0001260221-25-000081 | 10-K | XBRL Viewer

LEASES (Tables)

12 Months Ended

Sep. 30, 2025

The components of lease expense for the fiscal years ended September 30, 2025 and 2024 are as follows (in millions):


		Fiscal Years Ended September 30,
	Classification	2025		2024
Operating lease cost	Cost of sales or selling and administrative expenses	$	23	$	22
Finance lease cost:
Amortization of leased assets	Cost of sales	15		12
Interest on lease liabilities	Interest expense-net	19		16
Total lease cost		$	57	$	50

Schedule of Cash Flow, Supplemental Disclosures

Supplemental cash flow information related to leases for the fiscal years ended September 30, 2025 and 2024 is as follows (in millions):


	Fiscal Years Ended September 30,
	2025		2024
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows from operating leases	$	23	$	21
Operating cash outflows from finance leases	16		14
Financing cash outflows from finance leases	7		6

Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$	25	$	21
Financing leases	25		83

Operating Leases, Supplemental Balance Sheet Information

Supplemental balance sheet information related to leases is as follows (in millions):


	Classification	September 30, 2025		September 30, 2024
Operating Leases
Operating lease right-of-use assets	Other non-current assets	$	65	$	61

Current operating lease liabilities	Accrued and other current liabilities	15		19
Long-term operating lease liabilities	Other non-current liabilities	51		43
Total operating lease liabilities		$	66	$	62

Finance Leases
Finance lease right-of-use assets, net	Property, plant and equipment-net	$	264	$	252

Current finance lease liabilities	Current portion of long-term debt	8		6
Long-term finance lease liabilities	Long-term debt	276		256
Total finance lease liabilities		$	284	$	262

Leases, Weighted-Average Term and Discount Rate Remaining

As of September 30, 2025, the Company has the following remaining lease term and weighted average discount rates:


Weighted-average remaining lease term
Operating leases			6.4 years
Finance leases			19.8 years

Weighted-average discount rate
Operating leases			5.7%
Finance leases			7.0%

Finance Lease, Liability, Maturity

Maturities of lease liabilities at September 30, 2025 are as follows (in millions):


	Operating Leases		Finance Leases
2026	$	19	$	22
2027	16		26
2028	12		25
2029	9		25
2030	5		27
Thereafter	20		437
Total future minimum lease payments	81		562
Less: imputed interest	15		278
Present value of lease liabilities reported	$	66	$	284

Lessee, Operating Lease, Liability, Maturity

Maturities of lease liabilities at September 30, 2025 are as follows (in millions):


	Operating Leases		Finance Leases
2026	$	19	$	22
2027	16		26
2028	12		25
2029	9		25
2030	5		27
Thereafter	20		437
Total future minimum lease payments	81		562
Less: imputed interest	15		278
Present value of lease liabilities reported	$	66	$	284

PROPERTY, PLANT AND EQUIPMENT

12 Months Ended

Sep. 30, 2025

Property, Plant and Equipment [Abstract]

PROPERTY, PLANT AND EQUIPMENT

Property, plant and equipment consist of the following (in millions):


	September 30, 2025		September 30, 2024
Land and improvements	$	192	$	186
Buildings and improvements	794		733
Machinery, equipment and other	1,621		1,445
Construction-in-progress	163		141
Total	2,770		2,505
Accumulated depreciation	(1,191)		(1,017)
Property, plant and equipment—Net	$	1,579	$	1,488

AUDIT INFORMATION	12 Months Ended
AUDIT INFORMATION	Sep. 30, 2025
Audit Information [Abstract]
Auditor Firm ID	42
Auditor Name	Ernst & Young LLP
Auditor Location	Cleveland, Ohio

INCOME TAXES - Income Tax Provision on Income Before Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Current
Federal	$ 420	$ 354	$ 276
State	45	38	41
Foreign	100	98	97
Total Current	565	490	414
Deferred Federal Income Tax Expense (Benefit)	(32)	(6)	28
Deferred State and Local Income Tax Expense (Benefit)	1	7	11
Deferred Foreign Income Tax Expense (Benefit)	21	9	(36)
Deferred	(10)	10	3
INCOME TAX PROVISION	$ 555	$ 500	$ 417

LEASES - Maturities of Lease Liabilities Operating and Financing (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Leases [Abstract]
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	$ 19
Lessee, Operating Lease, Liability, Payments, Due Year Two	16
Lessee, Operating Lease, Liability, Payments, Due Year Three	12
Lessee, Operating Lease, Liability, Payments, Due Year Four	9
Lessee, Operating Lease, Liability, Payments, Due Year Five	5
Lessee, Operating Lease, Liability, Payments, Due after Year Five	20
Lessee, Operating Lease, Liability, Payments, Due	81
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	15
Operating Lease, Liability	66	$ 62
Finance Lease, Liability, Payments, Due Next Twelve Months	22
Finance Lease, Liability, Payments, Due Year Two	26
Finance Lease, Liability, Payments, Due Year Three	25
Finance Lease, Liability, Payments, Due Year Four	25
Finance Lease, Liability, Payments, Due Year Five	27
Finance Lease, Liability, Payments, Due after Year Five	437
Finance Lease, Liability, Payment, Due	562
Finance Lease, Liability, Undiscounted Excess Amount	278
Finance lease obligations	$ 284	$ 262

DEBT - Secured and Subordinate Notes (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Aug. 19, 2025	May 20, 2025
Senior Subordinated Notes
Debt Instrument [Line Items]
Long Term Debt, Principal Amount, Guaranteed	$ 200
Senior Subordinated Notes \| 6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”)
Debt Instrument [Line Items]
Interest rate	6.375%		6.375%
Senior Subordinated Notes \| 4.625% senior subordinated notes due 2029 (“4.625% 2029 Notes”)
Debt Instrument [Line Items]
Interest rate	4.625%
Senior Subordinated Notes \| 4.875% senior subordinated notes due 2029 (“4.875% 2029 Notes”)
Debt Instrument [Line Items]
Interest rate	4.875%
Senior Subordinated Notes \| 6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”)
Debt Instrument [Line Items]
Interest rate	6.75%	6.75%
Secured Debt
Debt Instrument [Line Items]
Long Term Debt, Principal Amount, Guaranteed	$ 200

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

DEBT - Schedule of Term Loans (Details) - USD ($) $ in Millions				12 Months Ended
	Sep. 17, 2025	Sep. 16, 2025	Aug. 19, 2025	Sep. 30, 2025	Sep. 30, 2024
Debt Instrument [Line Items]
Gross Amount				$ 29,520	$ 24,581
Term loans
Debt Instrument [Line Items]
Gross Amount				11,124	8,702
Tranche I \| Term loans
Debt Instrument [Line Items]
Gross Amount				$ 0	1,871
Debt Instrument, Basis Spread on Variable Rate				2.75%
Tranche J \| Term loans
Debt Instrument [Line Items]
Gross Amount				$ 3,595	3,632
Debt Instrument, Basis Spread on Variable Rate				2.50%
Tranche K \| Term loans
Debt Instrument [Line Items]
Gross Amount				$ 3,544	1,699
Debt Instrument, Basis Spread on Variable Rate	2.25%	2.75%		2.25%
Tranche L \| Term loans
Debt Instrument [Line Items]
Gross Amount				$ 1,485	1,500
Debt Instrument, Basis Spread on Variable Rate				2.50%
Tranche M \| Term loans
Debt Instrument [Line Items]
Gross Amount				$ 2,500	$ 0
Debt Instrument, Basis Spread on Variable Rate			2.50%	2.50%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

ACQUISITIONS - Servotronics, Inc. (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Jul. 01, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Jun. 02, 2025
Business Combination [Line Items]
Acquisition of businesses, net of cash acquired		$ 419	$ 2,347	$ 762
GOODWILL		$ 10,612	$ 10,419	$ 8,988
Servotronics, Inc.
Business Combination [Line Items]
Business combination, price per share (in dollars per share)					$ 47.00
Acquisition of businesses, net of cash acquired	$ 133
GOODWILL	75
Other intangible assets	$ 46

- Definition

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- Definition

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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+ Details

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
CURRENT ASSETS:
Cash and cash equivalents	$ 2,808	$ 6,261
Trade accounts receivable—Net	1,617	1,381
Inventories—Net	2,095	1,876
Prepaid expenses and other	492	511
Total current assets	7,012	10,029
PROPERTY, PLANT AND EQUIPMENT—NET	1,579	1,488
GOODWILL	10,612	10,419
OTHER INTANGIBLE ASSETS—NET	3,454	3,446
OTHER NON-CURRENT ASSETS	252	204
TOTAL ASSETS	22,909	25,586
CURRENT LIABILITIES:
Current portion of long-term debt	124	98
Short-term borrowings—trade receivable securitization facility	724	486
Accounts payable	368	323
Dividends payable	0	4,216
Accrued and other current liabilities	966	1,216
Total current liabilities	2,182	6,339
LONG-TERM DEBT	29,167	24,296
DEFERRED INCOME TAXES	759	766
OTHER NON-CURRENT LIABILITIES	480	468
Total liabilities	32,588	31,869
TD GROUP STOCKHOLDERS’ DEFICIT:
Common stock - $.01 par value; authorized 224,400,000 shares; issued 62,465,317 and 61,904,833 at September 30, 2025 and September 30, 2024, respectively	1	1
Additional paid-in capital	3,135	2,819
Accumulated deficit	(10,606)	(7,362)
Accumulated other comprehensive loss	(10)	(42)
Treasury stock, at cost; 6,089,675 and 5,688,639 shares at September 30, 2025 and September 30, 2024, respectively	(2,206)	(1,706)
Total TD Group stockholders’ deficit	(9,686)	(6,290)
NONCONTROLLING INTERESTS	7	7
Total stockholders’ deficit	(9,679)	(6,283)
TOTAL LIABILITIES AND STOCKHOLDERS’ DEFICIT	$ 22,909	$ 25,586

GOODWILL AND INTANGIBLE ASSETS - Summary of Changes in Carrying Value of Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 10,419	$ 8,988
Goodwill, Acquired During Period	202	1,349
Purchase price allocation adjustments	(38)	35
Currency translation adjustments and other	29	47
Goodwill, Ending Balance	10,612	10,419
Power & Control
Goodwill [Line Items]
Goodwill, Beginning Balance	5,034	4,208
Goodwill, Acquired During Period	189	786
Purchase price allocation adjustments	18	0
Currency translation adjustments and other	32	40
Goodwill, Ending Balance	5,273	5,034
Airframe
Goodwill [Line Items]
Goodwill, Beginning Balance	5,306	4,701
Goodwill, Acquired During Period	13	563
Purchase price allocation adjustments	(56)	35
Currency translation adjustments and other	(3)	7
Goodwill, Ending Balance	5,260	5,306
Non-aviation
Goodwill [Line Items]
Goodwill, Beginning Balance	79	79
Goodwill, Acquired During Period	0	0
Purchase price allocation adjustments	0	0
Currency translation adjustments and other	0	0
Goodwill, Ending Balance	$ 79	$ 79

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

SEGMENTS - Total Assets, Capital Expenditures and Depreciation and Amortization by Segment (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Total assets	$ 22,909	$ 25,586	$ 19,970
Capital expenditures	222	165	139
Depreciation and amortization expense	367	312	268
Operating Segments \| Power & Control
Segment Reporting Information [Line Items]
Total assets	9,859	9,180	7,356
Capital expenditures	108	90	67
Depreciation and amortization expense	180	133	110
Operating Segments \| Airframe
Segment Reporting Information [Line Items]
Total assets	10,267	10,045	8,972
Capital expenditures	103	73	65
Depreciation and amortization expense	181	172	152
Operating Segments \| Non-aviation
Segment Reporting Information [Line Items]
Total assets	202	193	193
Capital expenditures	9	2	6
Depreciation and amortization expense	6	6	5
Corporate
Segment Reporting Information [Line Items]
Total assets	2,581	6,168	3,449
Capital expenditures	2	0	1
Depreciation and amortization expense	$ 0	$ 1	$ 1

- Definition

Amount of asset recognized for present right to economic benefit.

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+ Details

- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References + Details

STOCK-BASED COMPENSATION - Summary of Activity, Pricing and Other Information for Performance Vested Stock-Based Award Activity (Detail)	12 Months Ended
	Sep. 30, 2025 USD ($) $ / shares shares
2019 Stock Option Plan
Number of Options
Number of Options, Granted	3,210,451
2019 Stock Option Plan \| Performance Vested Stock Options
Number of Options
Number of Options, Outstanding, beginning of period	561,109
Number of Options, Granted	346,664
Number of Options, Exercised	(26,420)
Number of Options, Forfeited	(121,745)
Number of Options, Expired	0
Number of Options, Outstanding, end of period	759,608
Number of Options, Expected to vest	409,971
Number of Options Exercisable at end of period	93,696
Weighted average exercise price per option
Weighted-Average Exercise Price Per Option, Outstanding, beginning of period \| $ / shares	$ 795.95
Weighted-Average Exercise Price Per Option, Granted \| $ / shares	1,316.43
Weighted-Average Exercise Price Per Option, Exercised \| $ / shares	656.47
Weighted-Average Exercise Price Per Option, Forfeited \| $ / shares	909.08
Weighted-Average Exercise Price Per Option, Expired \| $ / shares	0
Weighted-Average Exercise Price Per Option, Outstanding, end of period \| $ / shares	1,020.2
Weighted-Average Exercise Price Per Option, Expected to vest \| $ / shares	1,051.67
Weighted-Average Exercise Price Per Option, Exercisable \| $ / shares	$ 724.47
Weighted average remaining contractual term
Weighted-Average Remaining Contractual Term, Outstanding, years	8 years 4 months 24 days
Weighted-Average Remaining Contractual Term, Expected to vest, years	8 years 6 months
Weighted-Average Remaining Contractual Term, Exercisable, years	7 years 7 months 6 days
Aggregate intrinsic value
Aggregate Intrinsic Value, Outstanding \| $	$ 226,226,455
Aggregate Intrinsic Value, Expected to vest \| $	109,195,776
Aggregate Intrinsic Value, Exercisable \| $	$ 55,613,261
2014 Stock Option Plan \| Performance Vested Stock Options
Number of Options
Number of Options, Outstanding, beginning of period	3,779,503
Number of Options, Granted	0
Number of Options, Exercised	(462,368)
Number of Options, Forfeited	(86,209)
Number of Options, Expired	0
Number of Options, Outstanding, end of period	3,230,926
Number of Options, Expected to vest	478,730
Number of Options Exercisable at end of period	2,429,832
Weighted average exercise price per option
Weighted-Average Exercise Price Per Option, Outstanding, beginning of period \| $ / shares	$ 466.18
Weighted-Average Exercise Price Per Option, Granted \| $ / shares	0
Weighted-Average Exercise Price Per Option, Exercised \| $ / shares	288.80
Weighted-Average Exercise Price Per Option, Forfeited \| $ / shares	620.43
Weighted-Average Exercise Price Per Option, Expired \| $ / shares	0
Weighted-Average Exercise Price Per Option, Outstanding, end of period \| $ / shares	487.45
Weighted-Average Exercise Price Per Option, Expected to vest \| $ / shares	670.73
Weighted-Average Exercise Price Per Option, Exercisable \| $ / shares	$ 376.64
Weighted average remaining contractual term
Weighted-Average Remaining Contractual Term, Outstanding, years	4 years 4 months 24 days
Weighted-Average Remaining Contractual Term, Expected to vest, years	7 years 1 month 6 days
Weighted-Average Remaining Contractual Term, Exercisable, years	3 years 7 months 6 days
Aggregate intrinsic value
Aggregate Intrinsic Value, Outstanding \| $	$ 2,683,510,208
Aggregate Intrinsic Value, Expected to vest \| $	309,877,142
Aggregate Intrinsic Value, Exercisable \| $	$ 2,287,395,248

INCOME TAXES Income before Tax from Continuing Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Income before Tax from Continuing Operations [Abstract]
Income (Loss) from Continuing Operations before Income Taxes, Domestic	$ 2,119	$ 1,800	$ 1,413
Income (Loss) from Continuing Operations before Income Taxes, Foreign	510	415	303
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	$ 2,629	$ 2,215	$ 1,716

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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+ Details

INCOME TAXES - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 14	$ 17
Additions based on tax positions related to the prior year	7	1
Additions based on tax positions related to the current year	2	0
Reductions based on tax positions related to the prior year	0	0
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	0	3
Lapse in statute of limitations	0	(1)
Balance at end of period	$ 23	$ 14

ACCUMULATED OTHER COMPREHENSIVE LOSS

12 Months Ended

Sep. 30, 2025

Equity [Abstract]

ACCUMULATED OTHER COMPREHENSIVE LOSS

The following table presents the total changes by component in accumulated other comprehensive loss (“AOCL”), net of taxes, for the fiscal years ended September 30, 2025 and 2024 (in millions):


	Unrealized losses on derivatives (1)		Pension and post-retirement benefit plans adjustment (2)		Foreign currency translation adjustment (3)		Total
Balance at September 30, 2023	$	143	$	2	$	(243)	$	(98)


Net current-period other comprehensive (loss) income (4)	(124)		(1)		181		56
Balance at September 30, 2024	19		1		(62)		(42)


Net current-period other comprehensive (loss) income (4)	(23)		(3)		58		32
Balance at September 30, 2025	$	(4)	$	(2)	$	(4)	$	(10)

(1)Represents unrealized gains (losses) on derivatives designated and qualifying as cash flow hedges, net of tax (expense) benefit, of $8 million, $(37) million and $6 million for the fiscal years ended September 30, 2025, 2024 and 2023, respectively.

(2)There were no material pension liability adjustments, net of taxes, related to activity for the defined pension plans and postretirement benefit plans for the fiscal years ended September 30, 2025 and 2024.

(3)Represents gains (losses) resulting from foreign currency translation of financial statements, including gains (losses) from certain intercompany transactions, into U.S. dollars at the rates of exchange in effect at the balance sheet dates. Refer to Note 1, “Summary of Significant Accounting Policies,” for additional information.

(4)Presented net of reclassifications out of AOCL into earnings, specifically net sales and interest expense-net, for realized (losses) gains on derivatives designated and qualifying as cash flow hedges of $(1) million (net of taxes of less than $(1) million) and $57 million (net of taxes of $18 million), respectively, for the fiscal year ended September 30, 2025 and $(3) million (net of taxes of $(1) million) and $106 million (net of taxes of $33 million) for the fiscal year ended September 30, 2024, respectively.

DERIVATIVES AND HEDGING ACTIVITIES - Narratives (Detail) $ in Millions	12 Months Ended
	Sep. 30, 2025 USD ($)
Interest Rate Swap and Cap
Derivative [Line Items]
Derivative (gain) loss to be recognized	$ 7.0
Derivative, Notional Amount	2,750.0
Foreign Exchange Forward
Derivative [Line Items]
Derivative, Notional Amount	118.0
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Earnings, net of Tax, Next 12 months (Estimated)	$ (2.0)

GOODWILL AND INTANGIBLE ASSETS - Schedule of Intangible Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Intangible Asset, Acquired, Finite-Lived [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 4,851	$ 4,643
Intangible Assets, Accumulated Amortization	1,397	1,197
Total	3,454	3,446
Technology
Intangible Asset, Acquired, Finite-Lived [Line Items]
Gross Carrying Amount	2,647	2,510
Accumulated Amortization	1,137	1,003
Net	1,510	1,507
Order backlog
Intangible Asset, Acquired, Finite-Lived [Line Items]
Gross Carrying Amount	59	61
Accumulated Amortization	28	13
Net	31	48
Customer relationships
Intangible Asset, Acquired, Finite-Lived [Line Items]
Gross Carrying Amount	971	895
Accumulated Amortization	225	175
Net	746	720
Other Intangible Assets
Intangible Asset, Acquired, Finite-Lived [Line Items]
Gross Carrying Amount	12	12
Accumulated Amortization	7	6
Net	5	6
Trademarks and trade names
Intangible Asset, Acquired, Finite-Lived [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill), Gross	1,162	1,165
Indefinite-Lived Intangible Assets, Accumulated Amortization	0	0
Intangible Assets (Excluding Goodwill), Net	$ 1,162	$ 1,165

ACCRUED AND OTHER CURRENT LIABILITIES - Schedule of Accrued and Other Current Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Payables and Accruals [Abstract]
Compensation and related benefits	$ 235	$ 256
Income taxes payable, current	40	108
Interest	208	185
Contract liabilities, current (Note 3)	143	168
Product warranties	37	36
Dividend equivalent payments, current (Note 16)	59	180
Environmental and other litigation reserves	25	27
Current operating lease liabilities (Note 17)	15	19
Foreign currency forward exchange contracts (Note 18)	2	1
Other	202	236
Accrued and other current liabilities	$ 966	$ 1,216

TRADE ACCOUNTS RECEIVABLE (Tables)

12 Months Ended

Sep. 30, 2025

Receivables [Abstract]

Schedule of Trade Accounts Receivable

Trade accounts receivable consist of the following (in millions):


	September 30, 2025		September 30, 2024
Trade accounts receivable—gross	$	1,642	$	1,413
Allowance for uncollectible accounts	(25)		(32)
Trade accounts receivable—Net	$	1,617	$	1,381

EARNINGS PER SHARE - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Numerator for earnings per share:
Net income	$ 2,074	$ 1,715	$ 1,299
Less: Net income attributable to noncontrolling interests	0	1	1
Net income attributable to TD Group	2,074	1,714	1,298
Less: Dividends declared or paid on participating securities	(208)	(233)	(38)
NET INCOME APPLICABLE TO TD GROUP COMMON STOCKHOLDERS	$ 1,866	$ 1,481	$ 1,260
Denominator for basic and diluted earnings per share under the two-class method:
Weighted-average common shares outstanding - basic (in shares)	56.3	55.8	54.9
Weighted-average common shares outstanding - diluted (in shares)	56.3	55.8	54.9
Vested options deemed participating securities	1.9	2.0	2.3
Weighted-average shares outstanding - basic (in shares)	58.2	57.8	57.2
Weighted-average shares outstanding - diluted (in shares)	58.2	57.8	57.2
Earnings per share—basic (in usd per share)	$ 32.08	$ 25.62	$ 22.03
Earnings per share - diluted (in usd per share)	$ 32.08	$ 25.62	$ 22.03

INCOME TAXES (Tables)

12 Months Ended

Sep. 30, 2025

Income Tax Disclosure [Abstract]

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

The Company’s income from continuing operations before income taxes includes the following components for the periods shown below (in millions):


	Fiscal Years Ended September 30,
	2025		2024		2023
United States	$	2,119	$	1,800	$	1,413
Foreign	510		415		303
	$	2,629	$	2,215	$	1,716

Income Tax Provision on Income Before Income Taxes

The Company’s income tax provision (benefit) on income from continuing operations consists of the following for the periods shown below (in millions):


	Fiscal Years Ended September 30,
	2025		2024		2023
Current
Federal	$	420	$	354	$	276
State	45		38		41
Foreign	100		98		97
	565		490		414
Deferred
Federal	(32)		(6)		28
State	1		7		11
Foreign	21		9		(36)
	(10)		10		3
	$	555	$	500	$	417

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the federal statutory income tax rate to the effective income tax rate for the periods shown below is as follows:


	Fiscal Years Ended September 30,
	2025		2024		2023
Federal statutory income tax rate	21.0	%	21.0	%	21.0	%
Changes in valuation allowances impacting results	3.7	%	4.0	%	5.3	%
State and local income taxes, net of federal benefit	0.9	%	1.3	%	1.7	%
Foreign-derived intangible income	(1.6)	%	(1.2)	%	(1.2)	%
Stock-based compensation	(2.9)	%	(3.6)	%	(2.3)	%
Other—net	—	%	1.1	%	(0.2)	%
Effective income tax rate	21.1	%	22.6	%	24.3	%

Components of Deferred Taxes

The components of the deferred taxes consist of the following (in millions):


	September 30, 2025		September 30, 2024
Deferred tax assets (liabilities):
Intangible assets	$	(1,012)	$	(1,008)
Property, plant and equipment	(99)		(101)
Interest expense limitation	419		279
Employee benefits	131		115
Inventories	99		90
Capitalized research and development costs	86		73
Net operating losses	59		52
Other	14		52
Total	(303)		(448)
Add: Valuation allowance	(456)		(318)
Total net deferred tax assets (liabilities)	$	(759)	$	(766)

Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in millions):


	2025		2024
Balance at October 1	$	14	$	17

Additions based on tax positions related to the prior year	7		1
Additions based on tax positions related to the current year	2		—
Reductions based on tax positions related to the prior year	—		—
Settlement with tax authorities	—		(3)
Lapse in statute of limitations	—		(1)
Balance at September 30	$	23	$	14

INCOME TAXES - Income Tax Expense Reconciliation (Detail)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Statutory tax rate	21.00%	21.00%	21.00%
Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act, Percent	3.70%	4.00%	5.30%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	0.90%	1.30%	1.70%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization, Percent	(1.60%)	(1.20%)	(1.20%)
Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Percent	(2.90%)	(3.60%)	(2.30%)
Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent	0.00%	1.10%	(0.20%)
Effective Income Tax Rate Reconciliation, Percent	21.10%	22.60%	24.30%

LEASES - Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Leases [Abstract]
Operating Lease, Payments	$ 23	$ 21
Finance Lease, Interest Payment on Liability	16	14
Finance Lease, Principal Payments	7	6
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	25	21
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 25	$ 83

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Sep. 30, 2025
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES General Information TransDigm Group Incorporated (“TD Group”), through its wholly-owned subsidiary, TransDigm Inc., is a leading global designer, producer and supplier of highly engineered aircraft components that are critical to the safe and effective operation of nearly all commercial and military aircraft worldwide. Our products are represented in nearly every commercial and military aircraft in service today. TransDigm Inc., along with TransDigm Inc.’s direct and indirect wholly-owned operating subsidiaries (collectively, with TD Group, the “Company” or “TransDigm”), offers a broad range of proprietary aerospace products. TD Group has no significant assets or operations other than its 100% ownership of TransDigm Inc. TD Group’s common stock is listed on the New York Stock Exchange, or the NYSE, under the trading symbol “TDG.” As used in this Annual Report on Form 10-K, unless the context otherwise requires, the terms “Company”, “TD Group”, “TransDigm”, “we,” “our” or “us” refer to TransDigm Group Incorporated and its subsidiaries. Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements were prepared in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) and include the accounts of TD Group and subsidiaries. Intercompany balances and transactions have been eliminated. Certain reclassifications to the consolidated financial statements and notes have been made to the prior year amounts to conform to the current year presentation, none of which are material. Estimates – The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Revenue Recognition – The Company recognizes revenue from contracts with customers using the five step model prescribed in ASC 606. A substantial portion of the Company's revenue is recorded at a point in time basis. Revenue is recognized from the sale of products or services when obligations under the terms of the contract are satisfied and control of promised goods or services have transferred to the customer. Control is transferred when the customer has the ability to direct the use of and obtain benefits from the goods or services. Revenue is measured at the amount of consideration the Company expects to be paid in exchange for goods or services. Refer to Note 3, “Revenue Recognition,” for further information. Shipping and Handling Costs – Shipping and handling costs are included in cost of sales in the consolidated statements of income. Research and Development Costs – The Company expenses research and development costs as incurred and classifies such amounts in selling and administrative expenses. The expense recognized for research and development costs for the fiscal years ended September 30, 2025, 2024 and 2023 was approximately $118 million, $107 million, and $105 million, respectively. Cash Equivalents – The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash equivalents are recorded at cost, which approximates fair value. Allowance for Credit Losses – The Company's allowance for credit losses is the allowance for uncollectible accounts. The allowance for uncollectible accounts reduces the trade accounts receivable balance to the estimated net realizable value equal to the amount that is expected to be collected. The Company’s method for developing its allowance for credit losses is based on historical write-off experience, the aging of receivables, an assessment of the creditworthiness of customers, economic conditions and other external market information. The allowance also incorporates a provision for the estimated impact of disputes with customers. All provisions for allowances for uncollectible accounts are included in selling and administrative expenses. The determination of the amount of the allowance for uncollectible accounts is subject to judgment and estimation by management and is also assessed individually at each operating unit by the operating unit’s management team. If circumstances change or economic conditions deteriorate or improve, the allowance for uncollectible accounts could increase or decrease. Refer to Note 5, “Trade Accounts Receivable,” for further information. Inventories – Inventories are stated at the lower of cost or net realizable value. Cost of inventories is generally determined by the average actual cost and the first-in, first-out (“FIFO”) methods and includes material, labor and overhead related to the manufacturing process. Provision for potentially obsolete or slow-moving inventory is made based on management’s analysis of inventory levels, historical usage and future sales forecasts. Refer to Note 6, “Inventories,” for further information. Property, Plant and Equipment – Property, plant and equipment are stated at cost and include improvements which significantly increase capacities or extend the useful lives of existing plant and equipment. Depreciation is computed using the straight-line method over the following general estimated useful lives: land improvements from 10 to 20 years, buildings and improvements from 5 to 30 years, machinery and equipment from 2 to 10 years and furniture and fixtures from 3 to 10 years. Certain exceptions do apply in which an asset will have an estimated useful life outside of the range listed above dependent on, among other things, the nature and condition of the asset. Net gains or losses related to asset dispositions are recognized in earnings in the period in which dispositions occur. Routine maintenance, repairs and replacements are expensed as incurred. Amortization expense of assets accounted for as finance leases is included within depreciation expense. Property, plant and equipment is assessed for potential impairment whenever indicators of impairment are present by determining whether the carrying value of the property can be recovered through projected, undiscounted cash flows from future operations over the property’s remaining estimated useful life. Any impairment recognized is the amount by which the carrying amount exceeds the fair value of the asset. Fair value is measured based on quoted market prices in active markets, if available. If quoted market prices are not available, the estimate of fair value is based on various valuation techniques, including the discounted value of estimated future cash flows. No material impairments of long-lived assets were recorded in fiscal 2025, 2024 or 2023. Refer to Note 7, “Property, Plant and Equipment,” for further information. Financial Instruments – Interest rate swap, cap and collar agreements are used to manage interest rate risk associated with floating rate borrowings under our Second Amended and Restated Credit Agreement dated as of June 4, 2014 (the “Credit Agreement”). These agreements involve the receipt of floating rate amounts in exchange for fixed rate interest payments over the term of the agreements without an exchange of the underlying principal amount. The agreements utilized by the Company effectively modify the Company’s exposure to interest rate risk by converting a portion of the Company’s floating rate debt to a fixed rate basis from the effective date through the maturity date of the respective interest rate swap, cap and collar agreements, thereby reducing the impact of interest rate movements on future interest expense. These derivative instruments qualify as effective cash flow hedges under U.S. GAAP. The Company transacts business in various foreign currencies, which subjects the Company’s cash flows and results of operations to exposure related to changes in foreign currency exchange rates. These exposures arise primarily from purchases or sales of products and services from third parties. Foreign currency forward exchange contracts provide for the purchase or sale of foreign currencies at specified future dates at specified exchange rates, and are used to offset changes in the fair value of certain assets or liabilities or forecasted cash flows resulting from transactions denominated in foreign currencies. For the interest rate swap, cap and collar agreements and the foreign currency forward contracts designated as cash flow hedges, the effective portion of the gain or loss from the financial instruments is reported as a component of accumulated other comprehensive loss in stockholders’ deficit and subsequently reclassified into earnings in the same line as the hedged item in the same period or periods during which the hedged item affected earnings. As the interest rate swap, cap and collar agreements are used to manage interest rate risk, any gains or losses from the derivative instruments that are reclassified into earnings are recognized in interest expense-net in the consolidated statements of income. As the foreign currency forward exchange contracts are used to manage foreign currency exposure primarily arising from sales to third parties, any gains or losses from the derivative instruments that are reclassified into earnings are recognized in net sales in the consolidated statements of income. The cash flows from settled contracts are recognized in net cash provided by operating activities in the consolidated statements of cash flows. Refer to Note 18, “Derivatives and Hedging Activities,” for further information. Business Combinations – In accordance with ASC 805, “Business Combinations,” the Company uses the acquisition method of accounting to allocate costs of acquired businesses to the assets acquired and liabilities assumed based on their estimated fair values at the dates of acquisition. The excess costs of acquired businesses over the fair values of the assets acquired and liabilities assumed were recognized as goodwill. The valuations of the acquired assets and liabilities assumed will impact the determination of future operating results. Determining the fair value of assets acquired and liabilities assumed requires management’s judgment and often involves the use of estimates and assumptions which may be significant, including assumptions with respect to future cash inflows and outflows, revenue growth rates and earnings before interest, taxes, depreciation and amortization (“EBITDA”) margins, discount rates, customer attrition rates, royalty rates, asset lives and market multiples, among other items. These assumptions are forward looking and could be affected by future economic and market conditions. We determine the fair values of intangible assets acquired generally in consultation with third-party valuation advisors. Fair value adjustments to the Company’s assets and liabilities are recognized and the results of operations of the acquired business are included in our consolidated financial statements from the effective date of the merger or acquisition. Intangible assets other than goodwill are recognized if the benefit of the intangible asset is obtained through contractual or other legal rights, or if the intangible asset can be sold, transferred, licensed or exchanged, regardless of the Company’s intent to do so. Goodwill is the excess of the purchase price paid over the estimated fair value of the net assets of a business acquired. Other intangible assets consist of identifiable intangibles acquired or recognized in accounting for the acquisitions (trademarks, trade names, technology, customer relationships, order backlog and other intangible assets). Goodwill and intangible assets that have indefinite useful lives (i.e., trademarks and trade names) are subject to annual impairment testing or when indicators are present. Management determines fair value using a discounted future cash flow analysis or other accepted valuation techniques. Acquisition transaction-related expenses for the fiscal years ended September 30, 2025, 2024 and 2023 totaled approximately $6 million, $33 million and $6 million, respectively. These costs are expensed when incurred and included in selling and administrative expenses in the consolidated statements of income. Goodwill and Other Intangible Assets – The Company performs an annual impairment test for goodwill and other intangible assets as of the first day of the fourth fiscal quarter of each year, or more frequently, if an event occurs or circumstances change that would more likely than not reduce fair value below carrying value. We may elect to perform a qualitative assessment that considers economic, industry and company-specific factors for all or selected reporting units. If, after completing this assessment, it is determined that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value, we proceed to a quantitative test. We may also elect to perform a quantitative test instead of a qualitative assessment for any or all of our reporting units. In this application, the definition of “more-likely-than-not” is interpreted as a likelihood of more than 50%. For the quantitative test, management determines the estimated fair value through the use of a discounted cash flow valuation model incorporating discount rates commensurate with the risks involved for each reporting unit. If the estimated fair value of the reporting unit is less than the current carrying value, impairment of goodwill of the reporting unit is recognized. The assumptions used in the discounted cash flow valuation model for impairment testing includes discount rates, revenue growth rates and EBITDA margins, cash flow projections and terminal value rates. Discount rates are set by using the weighted average cost of capital (“WACC”) methodology. U.S. GAAP requires that the annual, and any interim, impairment assessment be performed at the reporting unit level. Our reporting units have been identified at the operating unit level, which is one level below our operating segments. Substantially all goodwill was determined and recognized for each reporting unit pursuant to the accounting for the merger or acquisition as of the date of each transaction. With respect to acquisitions integrated into an existing reporting unit, any acquired goodwill is combined with the goodwill of the reporting unit. The impairment test for indefinite lived intangible assets consists of a comparison between their fair values and carrying values. If the carrying amounts of intangible assets that have indefinite useful lives exceed their fair values, an impairment loss will be recognized in an amount equal to the sum of any such excesses. As of the first day of the fourth quarter of fiscal 2025, the date of the annual impairment test, no indefinite-lived intangible assets or goodwill was determined to be impaired. As economic and market conditions have not changed significantly since the first day of the fourth quarter, this conclusion remains appropriate as of September 30, 2025. The Company assesses the recoverability of its amortizable intangible assets only when indicators of impairment are present by determining whether the carrying value can be recovered through projected, undiscounted cash flows from future operations over their remaining lives. Amortization of amortizable intangible assets is computed using the straight-line method over the following general estimated useful lives: technology & other from 10 to 22 years, order backlog from 1 to 3 years, customer relationships from 10 to 20 years, and other intangible assets over 20 years. No indicators of impairment on the amortizable intangible assets were identified in fiscal 2025, 2024 or 2023. Stock-Based Compensation – The Company records stock-based compensation expense using the Black-Scholes pricing model based on certain valuation assumptions. Compensation expense is recorded over the vesting periods of the stock options, adjusted for expected forfeitures. The Company has classified stock-based compensation primarily within selling and administrative expenses to correspond with the classification of employees that receive stock option grants. The Company also evaluates any subsequent changes to the respective option holders terms under the modification rules of ASC 718. If determined to be a modification, the Black-Scholes pricing model is updated as of the date of the modification resulting in a cumulative catch up to expense, if necessary. Refer to Note 16, “Stock-Based Compensation,” for further information. Income Taxes – The provision for income taxes is calculated using the asset and liability method. Under the asset and liability method, deferred income taxes are recognized for the tax effect of temporary differences between the financial statement carrying amount of assets and liabilities and the amounts used for income tax purposes and for certain changes in valuation allowances. Valuation allowances are recorded to reduce certain deferred tax assets when, in our estimation, it is more likely than not that a tax benefit will not be realized. We recognize uncertain tax positions when we have determined it is more likely than not that a tax position will be sustained upon examination. However, new information may become available, or applicable laws or regulations may change, thereby resulting in a favorable or unfavorable adjustment to amounts recorded. Taxes related to Global Intangible Low-Taxed Income (“GILTI”) are treated as a current period expense when incurred. Refer to Note 12, “Income Taxes,” for further information. Comprehensive Income (Loss) – The term “comprehensive income (loss)” represents the change in stockholders’ equity (deficit) from transactions and other events and circumstances resulting from non-stockholder sources. The Company’s accumulated other comprehensive income or loss, consisting principally of fair value adjustments to its interest rate swap, cap and collar agreements (net of tax), cumulative foreign currency translation adjustments and pension liability adjustments (net of tax), is reported separately in the accompanying consolidated statements of comprehensive income. Foreign Currency Translation and Transactions – The assets and liabilities of subsidiaries located outside the United States are translated into U.S. dollars at the rates of exchange in effect at the balance sheet dates. Revenue and expense items are translated at the average monthly exchange rates prevailing during the period. Gains and losses resulting from foreign currency transactions are recognized currently in income and those resulting from translation of financial statements, including gains and losses from certain intercompany transactions, are accumulated as a separate component of other comprehensive income (loss) for the period. Foreign currency losses or (gains) recognized in cost of sales on the consolidated statements of income from changes in exchange rates were $10 million, $20 million and $14 million for the fiscal years ended September 30, 2025, 2024 and 2023, respectively. Earnings per Share – Earnings per share information is determined using the two-class method, which includes the weighted-average number of common shares outstanding during the period and other securities that participate in cash dividends (“participating securities”). Our vested stock options are considered “participating securities” because they include non-forfeitable rights to cash dividends. In applying the two-class method, earnings are allocated to both common shares and participating securities based on their respective weighted-average shares outstanding for the period. Diluted earnings per share information may include the additional effect of other securities, if dilutive, in which case the dilutive effect of such securities is calculated using the treasury stock method. Contingently issuable shares are not included in earnings per share until the period in which the contingency is satisfied. Refer to Note 4, “Earnings Per Share,” for further information. New Accounting Pronouncements Adopted In November 2023, the FASB issued ASU 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures.” ASU 2023-07 expands disclosures about a public business entity's reportable segments and provides for more detailed information about a reportable segment's expenses. Additionally, ASU 2023-07 requires all segment profit or loss and assets disclosures to be provided on an annual and interim basis. This standard is effective for annual periods beginning after December 15, 2023 (fiscal 2025) and interim periods within fiscal years beginning one year later (fiscal 2026). The Company adopted this standard in the fourth quarter of fiscal 2025. Refer to Note 15, “Segments,” for further information. New Accounting Pronouncements Issued In December 2023, the FASB issued ASU 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures,” which requires a public business entity to disclose specific categories in its annual effective tax rate reconciliation and disaggregated information about significant reconciling items by jurisdiction and by nature. The ASU also requires entities to disclose their income tax payments (net of refunds) to international, federal, and state and local jurisdictions. The standard makes several other changes to income tax disclosure requirements. This standard is effective for annual periods beginning after December 15, 2024 (fiscal 2026), and requires prospective application with the option to apply it retrospectively. Early adoption is permitted. The Company is currently evaluating this standard to determine its impact on our disclosures and believe that the adoption will not have a material impact on the consolidated financial statements and related disclosures. In November 2024, the FASB issued ASU 2024-03, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses.” Additionally, in January 2025, the FASB issued ASU 2025-01 to clarify the effective date of ASU 2024-03. The standard requires, among other items, additional disaggregated disclosures in the notes to financial statements for certain categories of expenses that are included on the face of the statement of income. The standard is effective for fiscal years beginning after December 15, 2026 (fiscal 2028), and for interim periods within fiscal years beginning after December 15, 2027 (fiscal 2029), on a retrospective or prospective basis, with early adoption permitted. The Company is currently evaluating this standard to determine its impact on our disclosures.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Sep. 30, 2025
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	The accompanying consolidated financial statements were prepared in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) and include the accounts of TD Group and subsidiaries. Intercompany balances and transactions have been eliminated.
Reclassification, Comparability Adjustment	Certain reclassifications to the consolidated financial statements and notes have been made to the prior year amounts to conform to the current year presentation, none of which are material.
Estimates	Estimates – The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Revenue Recognition	Revenue Recognition – The Company recognizes revenue from contracts with customers using the five step model prescribed in ASC 606. A substantial portion of the Company's revenue is recorded at a point in time basis. Revenue is recognized from the sale of products or services when obligations under the terms of the contract are satisfied and control of promised goods or services have transferred to the customer. Control is transferred when the customer has the ability to direct the use of and obtain benefits from the goods or services. Revenue is measured at the amount of consideration the Company expects to be paid in exchange for goods or services. Refer to Note 3, “Revenue Recognition,” for further information.
Shipping and Handling Costs	Shipping and Handling Costs – Shipping and handling costs are included in cost of sales in the consolidated statements of income.
Research and Development Expense	Research and Development Costs – The Company expenses research and development costs as incurred and classifies such amounts in selling and administrative expenses. The expense recognized for research and development costs for the fiscal years ended September 30, 2025, 2024 and 2023 was approximately $118 million, $107 million, and $105 million, respectively.
Cash and Cash Equivalents, Policy	Cash Equivalents – The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash equivalents are recorded at cost, which approximates fair value.
Credit Loss, Financial Instrument	Allowance for Credit Losses – The Company's allowance for credit losses is the allowance for uncollectible accounts. The allowance for uncollectible accounts reduces the trade accounts receivable balance to the estimated net realizable value equal to the amount that is expected to be collected. The Company’s method for developing its allowance for credit losses is based on historical write-off experience, the aging of receivables, an assessment of the creditworthiness of customers, economic conditions and other external market information. The allowance also incorporates a provision for the estimated impact of disputes with customers. All provisions for allowances for uncollectible accounts are included in selling and administrative expenses. The determination of the amount of the allowance for uncollectible accounts is subject to judgment and estimation by management and is also assessed individually at each operating unit by the operating unit’s management team. If circumstances change or economic conditions deteriorate or improve, the allowance for uncollectible accounts could increase or decrease. Refer to Note 5, “Trade Accounts Receivable,” for further information.
Inventories	Inventories – Inventories are stated at the lower of cost or net realizable value. Cost of inventories is generally determined by the average actual cost and the first-in, first-out (“FIFO”) methods and includes material, labor and overhead related to the manufacturing process. Provision for potentially obsolete or slow-moving inventory is made based on management’s analysis of inventory levels, historical usage and future sales forecasts. Refer to Note 6, “Inventories,” for further information.
Property, Plant and Equipment	Property, Plant and Equipment – Property, plant and equipment are stated at cost and include improvements which significantly increase capacities or extend the useful lives of existing plant and equipment. Depreciation is computed using the straight-line method over the following general estimated useful lives: land improvements from 10 to 20 years, buildings and improvements from 5 to 30 years, machinery and equipment from 2 to 10 years and furniture and fixtures from 3 to 10 years. Certain exceptions do apply in which an asset will have an estimated useful life outside of the range listed above dependent on, among other things, the nature and condition of the asset. Net gains or losses related to asset dispositions are recognized in earnings in the period in which dispositions occur. Routine maintenance, repairs and replacements are expensed as incurred. Amortization expense of assets accounted for as finance leases is included within depreciation expense. Property, plant and equipment is assessed for potential impairment whenever indicators of impairment are present by determining whether the carrying value of the property can be recovered through projected, undiscounted cash flows from future operations over the property’s remaining estimated useful life. Any impairment recognized is the amount by which the carrying amount exceeds the fair value of the asset. Fair value is measured based on quoted market prices in active markets, if available. If quoted market prices are not available, the estimate of fair value is based on various valuation techniques, including the discounted value of estimated future cash flows. No material impairments of long-lived assets were recorded in fiscal 2025, 2024 or 2023. Refer to Note 7, “Property, Plant and Equipment,” for further information.
Financial Instruments	Financial Instruments – Interest rate swap, cap and collar agreements are used to manage interest rate risk associated with floating rate borrowings under our Second Amended and Restated Credit Agreement dated as of June 4, 2014 (the “Credit Agreement”). These agreements involve the receipt of floating rate amounts in exchange for fixed rate interest payments over the term of the agreements without an exchange of the underlying principal amount. The agreements utilized by the Company effectively modify the Company’s exposure to interest rate risk by converting a portion of the Company’s floating rate debt to a fixed rate basis from the effective date through the maturity date of the respective interest rate swap, cap and collar agreements, thereby reducing the impact of interest rate movements on future interest expense. These derivative instruments qualify as effective cash flow hedges under U.S. GAAP. The Company transacts business in various foreign currencies, which subjects the Company’s cash flows and results of operations to exposure related to changes in foreign currency exchange rates. These exposures arise primarily from purchases or sales of products and services from third parties. Foreign currency forward exchange contracts provide for the purchase or sale of foreign currencies at specified future dates at specified exchange rates, and are used to offset changes in the fair value of certain assets or liabilities or forecasted cash flows resulting from transactions denominated in foreign currencies. For the interest rate swap, cap and collar agreements and the foreign currency forward contracts designated as cash flow hedges, the effective portion of the gain or loss from the financial instruments is reported as a component of accumulated other comprehensive loss in stockholders’ deficit and subsequently reclassified into earnings in the same line as the hedged item in the same period or periods during which the hedged item affected earnings. As the interest rate swap, cap and collar agreements are used to manage interest rate risk, any gains or losses from the derivative instruments that are reclassified into earnings are recognized in interest expense-net in the consolidated statements of income. As the foreign currency forward exchange contracts are used to manage foreign currency exposure primarily arising from sales to third parties, any gains or losses from the derivative instruments that are reclassified into earnings are recognized in net sales in the consolidated statements of income. The cash flows from settled contracts are recognized in net cash provided by operating activities in the consolidated statements of cash flows. Refer to Note 18, “Derivatives and Hedging Activities,” for further information.
Business Combinations	Business Combinations – In accordance with ASC 805, “Business Combinations,” the Company uses the acquisition method of accounting to allocate costs of acquired businesses to the assets acquired and liabilities assumed based on their estimated fair values at the dates of acquisition. The excess costs of acquired businesses over the fair values of the assets acquired and liabilities assumed were recognized as goodwill. The valuations of the acquired assets and liabilities assumed will impact the determination of future operating results. Determining the fair value of assets acquired and liabilities assumed requires management’s judgment and often involves the use of estimates and assumptions which may be significant, including assumptions with respect to future cash inflows and outflows, revenue growth rates and earnings before interest, taxes, depreciation and amortization (“EBITDA”) margins, discount rates, customer attrition rates, royalty rates, asset lives and market multiples, among other items. These assumptions are forward looking and could be affected by future economic and market conditions. We determine the fair values of intangible assets acquired generally in consultation with third-party valuation advisors. Fair value adjustments to the Company’s assets and liabilities are recognized and the results of operations of the acquired business are included in our consolidated financial statements from the effective date of the merger or acquisition. Intangible assets other than goodwill are recognized if the benefit of the intangible asset is obtained through contractual or other legal rights, or if the intangible asset can be sold, transferred, licensed or exchanged, regardless of the Company’s intent to do so. Goodwill is the excess of the purchase price paid over the estimated fair value of the net assets of a business acquired. Other intangible assets consist of identifiable intangibles acquired or recognized in accounting for the acquisitions (trademarks, trade names, technology, customer relationships, order backlog and other intangible assets). Goodwill and intangible assets that have indefinite useful lives (i.e., trademarks and trade names) are subject to annual impairment testing or when indicators are present. Management determines fair value using a discounted future cash flow analysis or other accepted valuation techniques. Acquisition transaction-related expenses for the fiscal years ended September 30, 2025, 2024 and 2023 totaled approximately $6 million, $33 million and $6 million, respectively. These costs are expensed when incurred and included in selling and administrative expenses in the consolidated statements of income.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets – The Company performs an annual impairment test for goodwill and other intangible assets as of the first day of the fourth fiscal quarter of each year, or more frequently, if an event occurs or circumstances change that would more likely than not reduce fair value below carrying value. We may elect to perform a qualitative assessment that considers economic, industry and company-specific factors for all or selected reporting units. If, after completing this assessment, it is determined that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value, we proceed to a quantitative test. We may also elect to perform a quantitative test instead of a qualitative assessment for any or all of our reporting units. In this application, the definition of “more-likely-than-not” is interpreted as a likelihood of more than 50%. For the quantitative test, management determines the estimated fair value through the use of a discounted cash flow valuation model incorporating discount rates commensurate with the risks involved for each reporting unit. If the estimated fair value of the reporting unit is less than the current carrying value, impairment of goodwill of the reporting unit is recognized. The assumptions used in the discounted cash flow valuation model for impairment testing includes discount rates, revenue growth rates and EBITDA margins, cash flow projections and terminal value rates. Discount rates are set by using the weighted average cost of capital (“WACC”) methodology. U.S. GAAP requires that the annual, and any interim, impairment assessment be performed at the reporting unit level. Our reporting units have been identified at the operating unit level, which is one level below our operating segments. Substantially all goodwill was determined and recognized for each reporting unit pursuant to the accounting for the merger or acquisition as of the date of each transaction. With respect to acquisitions integrated into an existing reporting unit, any acquired goodwill is combined with the goodwill of the reporting unit. The impairment test for indefinite lived intangible assets consists of a comparison between their fair values and carrying values. If the carrying amounts of intangible assets that have indefinite useful lives exceed their fair values, an impairment loss will be recognized in an amount equal to the sum of any such excesses. As of the first day of the fourth quarter of fiscal 2025, the date of the annual impairment test, no indefinite-lived intangible assets or goodwill was determined to be impaired. As economic and market conditions have not changed significantly since the first day of the fourth quarter, this conclusion remains appropriate as of September 30, 2025. The Company assesses the recoverability of its amortizable intangible assets only when indicators of impairment are present by determining whether the carrying value can be recovered through projected, undiscounted cash flows from future operations over their remaining lives. Amortization of amortizable intangible assets is computed using the straight-line method over the following general estimated useful lives: technology & other from 10 to 22 years, order backlog from 1 to 3 years, customer relationships from 10 to 20 years, and other intangible assets over 20 years. No indicators of impairment on the amortizable intangible assets were identified in fiscal 2025, 2024 or 2023.
Stock-Based Compensation	Stock-Based Compensation – The Company records stock-based compensation expense using the Black-Scholes pricing model based on certain valuation assumptions. Compensation expense is recorded over the vesting periods of the stock options, adjusted for expected forfeitures. The Company has classified stock-based compensation primarily within selling and administrative expenses to correspond with the classification of employees that receive stock option grants. The Company also evaluates any subsequent changes to the respective option holders terms under the modification rules of ASC 718. If determined to be a modification, the Black-Scholes pricing model is updated as of the date of the modification resulting in a cumulative catch up to expense, if necessary. Refer to Note 16, “Stock-Based Compensation,” for further information.
Income Taxes	Income Taxes – The provision for income taxes is calculated using the asset and liability method. Under the asset and liability method, deferred income taxes are recognized for the tax effect of temporary differences between the financial statement carrying amount of assets and liabilities and the amounts used for income tax purposes and for certain changes in valuation allowances. Valuation allowances are recorded to reduce certain deferred tax assets when, in our estimation, it is more likely than not that a tax benefit will not be realized. We recognize uncertain tax positions when we have determined it is more likely than not that a tax position will be sustained upon examination. However, new information may become available, or applicable laws or regulations may change, thereby resulting in a favorable or unfavorable adjustment to amounts recorded. Taxes related to Global Intangible Low-Taxed Income (“GILTI”) are treated as a current period expense when incurred. Refer to Note 12, “Income Taxes,” for further information.
Comprehensive Income (Loss)	Comprehensive Income (Loss) – The term “comprehensive income (loss)” represents the change in stockholders’ equity (deficit) from transactions and other events and circumstances resulting from non-stockholder sources. The Company’s accumulated other comprehensive income or loss, consisting principally of fair value adjustments to its interest rate swap, cap and collar agreements (net of tax), cumulative foreign currency translation adjustments and pension liability adjustments (net of tax), is reported separately in the accompanying consolidated statements of comprehensive income.
Foreign Currency Translations and Transactions	Foreign Currency Translation and Transactions – The assets and liabilities of subsidiaries located outside the United States are translated into U.S. dollars at the rates of exchange in effect at the balance sheet dates. Revenue and expense items are translated at the average monthly exchange rates prevailing during the period. Gains and losses resulting from foreign currency transactions are recognized currently in income and those resulting from translation of financial statements, including gains and losses from certain intercompany transactions, are accumulated as a separate component of other comprehensive income (loss) for the period. Foreign currency losses or (gains) recognized in cost of sales on the consolidated statements of income from changes in exchange rates were $10 million, $20 million and $14 million for the fiscal years ended September 30, 2025, 2024 and 2023, respectively.
Earnings per Share	Earnings per Share – Earnings per share information is determined using the two-class method, which includes the weighted-average number of common shares outstanding during the period and other securities that participate in cash dividends (“participating securities”). Our vested stock options are considered “participating securities” because they include non-forfeitable rights to cash dividends. In applying the two-class method, earnings are allocated to both common shares and participating securities based on their respective weighted-average shares outstanding for the period. Diluted earnings per share information may include the additional effect of other securities, if dilutive, in which case the dilutive effect of such securities is calculated using the treasury stock method. Contingently issuable shares are not included in earnings per share until the period in which the contingency is satisfied. Refer to Note 4, “Earnings Per Share,” for further information.
New Accounting Pronouncements Adopted and New Accounting Pronouncements Issued	New Accounting Pronouncements Adopted In November 2023, the FASB issued ASU 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures.” ASU 2023-07 expands disclosures about a public business entity's reportable segments and provides for more detailed information about a reportable segment's expenses. Additionally, ASU 2023-07 requires all segment profit or loss and assets disclosures to be provided on an annual and interim basis. This standard is effective for annual periods beginning after December 15, 2023 (fiscal 2025) and interim periods within fiscal years beginning one year later (fiscal 2026). The Company adopted this standard in the fourth quarter of fiscal 2025. Refer to Note 15, “Segments,” for further information. New Accounting Pronouncements Issued In December 2023, the FASB issued ASU 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures,” which requires a public business entity to disclose specific categories in its annual effective tax rate reconciliation and disaggregated information about significant reconciling items by jurisdiction and by nature. The ASU also requires entities to disclose their income tax payments (net of refunds) to international, federal, and state and local jurisdictions. The standard makes several other changes to income tax disclosure requirements. This standard is effective for annual periods beginning after December 15, 2024 (fiscal 2026), and requires prospective application with the option to apply it retrospectively. Early adoption is permitted. The Company is currently evaluating this standard to determine its impact on our disclosures and believe that the adoption will not have a material impact on the consolidated financial statements and related disclosures. In November 2024, the FASB issued ASU 2024-03, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses.” Additionally, in January 2025, the FASB issued ASU 2025-01 to clarify the effective date of ASU 2024-03. The standard requires, among other items, additional disaggregated disclosures in the notes to financial statements for certain categories of expenses that are included on the face of the statement of income. The standard is effective for fiscal years beginning after December 15, 2026 (fiscal 2028), and for interim periods within fiscal years beginning after December 15, 2027 (fiscal 2029), on a retrospective or prospective basis, with early adoption permitted. The Company is currently evaluating this standard to determine its impact on our disclosures.

DEBT

12 Months Ended

Sep. 30, 2025

Debt Disclosure [Abstract]

DEBT

The Company’s debt consists of the following (in millions):


	September 30, 2025
	Gross Amount		Debt Issuance Costs		Original Issue Discount		Net Amount
Short-term borrowings—trade receivable securitization facility	$	725	$	(1)	$	—	$	724
Term loans	$	11,124	$	(43)	$	(33)	$	11,048
6.750% secured notes due 2028 (“2028 Secured Notes”)	2,100		(11)		(6)		2,083
4.625% senior subordinated notes due 2029 (“4.625% 2029 Notes”)	1,200		(5)		—		1,195
6.375% secured notes due 2029 (“2029 Secured Notes”)	2,750		(17)		(1)		2,732
4.875% senior subordinated notes due 2029 (“4.875% 2029 Notes”)	750		(3)		—		747
6.875% secured notes due 2030 (“2030 Secured Notes”)	1,450		(10)		—		1,440
7.125% secured notes due 2031 (“2031 Secured Notes”)	1,000		(8)		(6)		986
6.625% secured notes due 2032 (“2032 Secured Notes”)	2,200		(17)		—		2,183
6.000% secured notes due 2033 (“2033 Secured Notes”)	1,500		(12)		—		1,488
6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”)	2,650		(14)		(20)		2,616
6.250% secured notes due 2034 (“2034 Secured Notes”)	500		(5)		—		495
6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”)	2,000		(18)		—		1,982
Government refundable advances	12		—		—		12
Finance lease obligations	284		—		—		284
	29,520		(163)		(66)		29,291
Less: current portion	125		(1)		—		124
Long-term debt	$	29,395	$	(162)	$	(66)	$	29,167


	September 30, 2024
	Gross Amount		Debt Issuance Costs		Original Issue Discount		Net Amount
Short-term borrowings—trade receivable securitization facility	$	487	$	(1)	$	—	$	486
Term loans	$	8,702	$	(25)	$	(35)	$	8,642
5.500% senior subordinated notes due 2027 (“5.500% 2027 Notes”)	2,650		(9)		—		2,641
2028 Secured Notes	2,100		(15)		(8)		2,077
4.625% 2029 Notes	1,200		(6)		—		1,194
2029 Secured Notes	2,750		(22)		(1)		2,727
4.875% 2029 Notes	750		(4)		—		746
2030 Secured Notes	1,450		(12)		—		1,438
2031 Secured Notes	1,000		(9)		(7)		984
2032 Secured Notes	2,200		(20)		—		2,180
2033 Secured Notes	1,500		(14)		—		1,486
Government refundable advances	17		—		—		17
Finance lease obligations	262		—		—		262
	24,581		(136)		(51)		24,394
Less: current portion	99		(1)		—		98
Long-term debt	$	24,482	$	(135)	$	(51)	$	24,296

Issuance of $2,650 million of Senior Subordinated Notes due 2033 – On May 20, 2025, the Company entered into a purchase agreement in connection with a private offering of $2,650 million in aggregate principal amount consisting of the 6.375% 2033 Notes at an issue price of 99.225% of the principal amount, which represents an approximately $20.5 million discount. The 6.375% 2033 Notes were issued pursuant to an indenture, dated as of May 20, 2025, amongst TransDigm Inc., as issuer, TransDigm Group and the other subsidiaries of TransDigm Inc. named therein, as guarantors. The 6.375% 2033 Notes bear interest at the rate of 6.375% per annum, which accrues from May 20, 2025 and is payable in arrears on November 30 and May 31 of each year, commencing on November 30, 2025. The 6.375% 2033 Notes mature on May 31, 2033, unless earlier redeemed or repurchased, and are subject to the terms and conditions set forth in the related indenture.

The Company capitalized $14 million in debt issuance costs associated with the 6.375% 2033 Notes during the fiscal year ended September 30, 2025.

Redemption of $2,650 million of Senior Subordinated Notes due 2027 – On June 20, 2025, the Company redeemed all $2,650 million aggregate principal of its outstanding 5.500% 2027 Notes at a redemption price of 100% of the principal amount thereof, plus accrued and unpaid interest thereon to, but not including, the redemption date, using the net proceeds of the offering of the 6.375% 2033 Notes (as further described above), together with existing cash on hand.

The Company recorded refinancing costs of $7 million, consisting of the write-off of the unamortized debt issuance costs during the fiscal year ended September 30, 2025 in conjunction with the redemption of the 5.500% 2027 Notes.

Issuance of $500 million of Senior Secured Notes due 2034 – On August 19, 2025, the Company entered into a purchase agreement in connection with a private offering of $500 million in aggregate principal amount consisting of the 2034 Secured Notes at an issue price of 100% of the principal amount. The 2034 Secured Notes were issued pursuant to an indenture, dated as of August 19, 2025, among TransDigm Inc., as issuer, TransDigm Group and the subsidiaries of TransDigm named therein, as guarantors. The 2034 Secured Notes bear interest at the rate of 6.250% per annum, which accrues from August 19, 2025 and is payable in arrears on January 31 and July 31 of each year, commencing on January 31, 2026. The 2034 Secured Notes mature on January 31, 2034, unless earlier redeemed or repurchased, and are subject to the terms and conditions set forth in the related indenture.

The Company capitalized approximately $5 million in debt issuance costs associated with the 2034 Secured Notes during the fiscal year ended September 30, 2025.

Issuance of $2,000 Subordinated Notes due 2034 - On August 19, 2025, the Company entered into a purchase agreement in connection with a private offering of $2,000 million in aggregate principal amount consisting of 6.750% 2034 Notes at an issue price of 100% of the principal amount. The 6.750% 2034 Notes were issued pursuant to an indenture, dated as of August 19, 2025 amongst TransDigm Inc., as issuer, TransDigm Group and the other subsidiaries of TransDigm Inc. named therein, as guarantors. The 6.750% 2034 Notes bear interest at the rate of 6.750% per annum, which accrues from August 19, 2025, and is payable in arrears on January 31 and July 31 of each year, commencing on January 31, 2026. The 6.750% 2034 Notes mature on January 31, 2034, unless earlier redeemed or repurchased, and are subject to the terms and conditions set forth in the related indenture.

The Company capitalized approximately $18 million in debt issuance costs associated with the 2034 Secured Notes during the fiscal year ended September 30, 2025.

Amendment No. 18 and Incremental Term Loan Assumption Agreement - On August 19, 2025, the Company entered into Amendment No. 18 and Incremental Term Loan Assumption Agreement (herein, “Amendment No. 18”), pursuant to which the Company, among other things, incurred $2,500 million in new Tranche M term loans. Original issue discount of 0.25%, or approximately $6 million, was paid to the lenders of the Tranche M term loans. The other terms and conditions that apply to the Tranche M term loans are substantially the same as the terms and conditions that apply to the other term loans existing under the Term Loans Facility. The Tranche M term loans were fully drawn on August 19, 2025. Principal payments commence on December 31, 2025, in which approximately $6 million is to be paid on a quarterly basis up to the August 19, 2032 maturity date.

The Tranche M term loans bear interest at the rate of Term SOFR plus 2.50% per annum, which accrues from August 19, 2025, and is payable in arrears on March 31, June 30, September 30, and December 31 of each year, commencing on December 31, 2025.

The Company capitalized $23 million in debt issuance costs associated with Amendment No. 18 during the fiscal year ended September 30, 2025.

The proceeds from the August 19, 2025 issuances of the 2034 Secured Notes, the 6.750% 2034 Notes and the Tranche M term loans were used, along with existing cash on hand, to fund a $90.00 special dividend declaration on each outstanding share of common stock and cash dividend equivalent payments on eligible vested options outstanding under its stock option plans and for related fees and expenses.

Amendment No. 19 Loan Modification Agreement and Refinancing Facility Agreement - On September 17, 2025, the Company entered into Amendment No. 19, Loan Modification Agreement and Refinancing Facility Agreement (herein, “Amendment No. 19”), pursuant to which the Company, among other things, (i) repriced all of its $1,686 million in existing Tranche K term loans to bear interest at Term SOFR plus 2.25% compared to Term SOFR plus 2.75% applicable prior to Amendment No. 19; and (ii) amended and extended $1,857 million in existing Tranche I term loans maturing August 24, 2028 and converting such loans into new Tranche K term loans maturing March 22, 2030 (herein, “the New Tranche K Term Loans”). The other terms and conditions that apply to the New Tranche K Term Loans are substantially the same as the terms and conditions that applied to the other term loans existing under the Term Loans Facility. Principal payments commence on December 31, 2025, in which approximately $9 million is to be paid on a quarterly basis up to the March 22, 2030 maturity date.

The New Tranche K Term Loans bear interest at the rate of Term SOFR plus 2.25% per annum compared to Term SOFR plus 2.75% applicable prior to Amendment No. 19. Interest accrues from September 17, 2025, and is payable in arrears on March 31, June 30, September 30, and December 31 of each year, commencing on December 31, 2025.

The Company recorded refinancing costs of $3 million associated with Amendment No. 19 during the fiscal year ended September 30, 2025.

Trade Receivable Securitization Facility – The Company’s trade receivable securitization facility (the “Securitization Facility”) effectively increases the Company’s borrowing capacity depending on the amount of the domestic operations’ trade accounts receivable. The Securitization Facility includes the right for the Company to exercise annual one year extensions as long as there have been no termination events as defined by the agreement. The Company uses the proceeds from the Securitization Facility as an alternative to other forms of debt, effectively reducing borrowing costs.

On July 11, 2025, the Company amended the Securitization Facility to, among other things, (i) increase the borrowing capacity from $650 million to $725 million; and (ii) extend the maturity date to July 10, 2026 at an interest rate of Term SOFR plus 1.35% compared to an interest rate of Term SOFR plus 1.45% that applied prior to the amendment.

The Company drew $163 million and $75 million available under the Securitization Facility in October 2024 and September 2025, respectively. As of September 30, 2025, the total drawn on the Securitization Facility is $725 million. For the fiscal years ended September 30, 2025 and 2024, the applicable interest rate was 5.67% and 6.73%, respectively. The Securitization Facility is collateralized by substantially all of the Company’s domestic operations’ trade accounts receivable.

Government Refundable Advances

Government refundable advances consist of payments received from the Canadian government to assist in research and development related to commercial aviation. The requirement to repay this advance is based on year-over-year commercial aviation revenue growth for certain product lines at CMC Electronics, which is a wholly-owned subsidiary of TransDigm. As of September 30, 2025 and 2024, the outstanding balance of these advances were $12 million and $17 million, respectively.

Obligations under Finance Leases

The Company leases certain buildings and equipment under finance leases. The present value of the minimum finance lease payments, net of the current portion, represents a balance of $284 million and $262 million at September 30, 2025 and 2024, respectively. The increase in fiscal 2025 is primarily attributable to certain new leases of facilities and amendments to previous agreements qualifying as lease modifications resulting in a change in classification from an operating lease to a finance lease. Refer to Note 17, “Leases,” for further disclosure of the Company’s lease obligations.

Senior Secured Term Loans Facility

As of September 30, 2025, TransDigm had $11,124 million in fully drawn term loans under the Term Loans Facility, $910 million in revolving commitments, of which $857 million was available to the Company, subject to an interest rate of 2.25% per annum. As of September 30, 2024, TransDigm had $8,702 million in fully drawn term loans, $910 million in revolving commitments, of which $843 million was available to the Company, subject to an interest rate of 2.25% per annum. The unused portion of the revolving commitments is subject to a fee of 0.5% per annum for both fiscal 2025 and 2024. The total fees incurred on the unused portion of the revolving commitments were not material in fiscal 2025 or fiscal 2024. TransDigm is in compliance with all the covenants contained in the Term Loans Facility.


Term Loans Facility	Maturity Date	Interest Rate under Term Loans Facility	Aggregate Principal as of September 30,
			2025		2024
Tranche I (1)	August 24, 2028	Term SOFR plus 2.75%	$	—	$	1,871
Tranche J	February 28, 2031	Term SOFR plus 2.50%	$	3,595	$	3,632
Tranche K	March 22, 2030	Term SOFR plus 2.25%	$	3,544	$	1,699
Tranche L	January 19, 2032	Term SOFR plus 2.50%	$	1,485	$	1,500
Tranche M	August 19, 2032	Term SOFR plus 2.50%	$	2,500	$	—

(1)As previously disclosed within this note, during fiscal 2025, Tranche I was converted into Tranche K.

The interest rates per annum applicable to the loans under the Term Loans Facility are, at TransDigm’s option, equal to either an alternate base rate or an adjusted Term SOFR for one, three or six-months thereafter (in each case, subject to the availability thereof), interest periods chosen by TransDigm, in each case, plus an applicable margin percentage. The adjusted Term SOFR related to the existing term loans are not subject to a floor. Refer to Note 18, “Derivatives and Hedging Activities,” for information about how our interest rate swaps, cap and collar agreements are used to hedge and offset, respectively, the variable interest rates on the Term Loans Facility.

Secured Notes

TransDigm Inc.’s 2028 Secured Notes are jointly and severally guaranteed, on a senior basis, by TransDigm Group, TransDigm UK and all of TransDigm Inc.'s Domestic Restricted Subsidiaries, as defined in the applicable indentures. The 2029 Secured Notes, 2030 Secured Notes, 2031 Secured Notes, 2032 Secured Notes, 2033 Secured Notes and 2034 Secured Notes (collectively with the 2028 Secured Notes, the “Secured Notes”) are guaranteed on a senior secured basis by TransDigm Group and each of TransDigm Inc.’s direct and indirect Restricted Subsidiaries (as defined in the applicable indenture) that is a borrower or guarantor under TransDigm’s senior secured credit facilities or that issues or guarantees any capital market indebtedness of TransDigm Inc. or any of the guarantors in an aggregate principal amount of at least $200 million. The guarantees of the Secured Notes rank equally in right of payment with all of the guarantors’ existing and future senior secured debt and are senior in right of payment to all of their existing and future senior subordinated debt. The Secured Notes are structurally subordinated to all of the liabilities of TransDigm’s non-guarantor subsidiaries. As of the date of this Form 10-K, the guarantors of the 2029 Secured Notes, 2030 Secured Notes, 2031 Secured Notes, 2032 Secured Notes, 2033 Secured Notes and 2034 Secured Notes are the same as the guarantors of the 2028 Secured Notes. The Secured Notes contain restrictive covenants that are substantially similar to many of the restrictive covenants included in the Credit Agreement. TransDigm is in compliance with all the covenants contained in the Secured Notes.

Subordinated Notes

The 4.625% 2029 Notes and the 4.875% 2029 Notes are fully and unconditionally guaranteed on a senior subordinated unsecured basis by TransDigm Group, TransDigm UK and TransDigm Inc.’s Domestic Restricted Subsidiaries (as defined in the applicable indentures). The 6.375% 2033 Notes and the 6.750% 2034 Notes are guaranteed, on a senior subordinated basis, by TransDigm Group and each of TransDigm Inc.’s direct and indirect restricted subsidiaries that is a borrower or guarantor under TransDigm’s senior secured credit facilities or that issues or guarantees any capital markets indebtedness of TransDigm or any of the guarantors in an aggregate principal amount of at least $200 million. The guarantees of the Subordinated Notes are subordinated to all of the guarantors’ existing and future senior debt, rank equally with all of their existing and future senior subordinated debt and rank senior to all of their future debt that is expressly subordinated to the guarantees of the Subordinated Notes. The Subordinated Notes are structurally subordinated to all of the liabilities of TransDigm Group’s non-guarantor subsidiaries. The Subordinated Notes contain restrictive covenants that are substantially similar to many of the restrictive covenants included in the Credit Agreement. TransDigm is in compliance with all the covenants contained in the Subordinated Notes.

Debt Repayment Schedule

At September 30, 2025, future maturities of long-term debt (excluding finance leases) are as follows (in millions), refer to Note 17, “Leases,” for future maturities of finance leases:


Fiscal Years Ended September 30,
2026	$	116
2027	116
2028	2,216
2029	4,812
2030	3,478
Thereafter	18,498
Total	$	29,236

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

GOODWILL AND INTANGIBLE ASSETS

12 Months Ended

Sep. 30, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

GOODWILL AND INTANGIBLE ASSETS

The following is a summary of changes in the carrying value of goodwill by segment for the fiscal years ended September 30, 2024 and 2025 (in millions):


	Power & Control		Airframe		Non-aviation		Total
Balance at September 30, 2023	$	4,208	$	4,701	$	79	$	8,988
Goodwill acquired during the period	786		563		—		1,349
Purchase price allocation adjustments (1)	—		35		—		35
Currency translation adjustments and other	40		7		—		47
Balance at September 30, 2024	5,034		5,306		79		10,419
Goodwill acquired during the period	189		13		—		202
Purchase price allocation adjustments (2)	18		(56)		—		(38)
Currency translation adjustments and other	32		(3)		—		29
Balance at September 30, 2025	$	5,273	$	5,260	$	79	$	10,612

(1)Primarily related to the opening balance sheet adjustments recorded from the fiscal 2023 acquisition of Calspan Corporation within the allowable measurement period (not to exceed one year).

(2)Primarily related to the opening balance sheet adjustments recorded from the acquisition of Raptor Scientific (Airframe) completed during the fourth quarter of fiscal 2024 and CPI's Electron Device Business (Power & Control) completed during the third quarter of fiscal 2024, within the allowable measurement period (not to exceed one year).

Other intangible assets–net in the consolidated balance sheets consist of the following at September 30 (in millions):


	2025						2024
	Gross Carrying Amount		Accumulated Amortization		Net		Gross Carrying Amount		Accumulated Amortization		Net
Trademarks and trade names	$	1,162	$	—	$	1,162	$	1,165	$	—	$	1,165
Technology	2,647		1,137		1,510		2,510		1,003		1,507
Order backlog	59		28		31		61		13		48
Customer relationships	971		225		746		895		175		720
Other	12		7		5		12		6		6
Total	$	4,851	$	1,397	$	3,454	$	4,643	$	1,197	$	3,446

The estimated fair value of the net identifiable tangible and intangible assets acquired is based on the acquisition method of accounting. The fair value of the net identifiable tangible and intangible assets acquired will be finalized within the measurement period (not to exceed one year). Intangible assets acquired during the fiscal year ended September 30, 2025 are summarized in the table below (in millions):


	Gross Amount		Amortization Period
Intangible assets not subject to amortization:
Trademarks and trade names	$	11

Intangible assets subject to amortization:
Technology & Other	71		10 to 20 years
Order backlog	17		1 year
Customer relationships	37		10 to 20 years
	125

Total	$	136

Information regarding the amortization expense of amortizable intangible assets is detailed below (in millions):

Annual Amortization Expense:


Fiscal Years Ended September 30,
2025	$	201
2024	161
2023	139

Estimated Amortization Expense:


Fiscal Years Ended September 30,
2026	$	203
2027	187
2028	179
2029	178
2030	170

ACQUISITIONS - Other Acquisitions (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Business Combination [Line Items]
Acquisition of businesses, net of cash acquired	$ 419	$ 2,347	$ 762
GOODWILL	$ 10,612	10,419	$ 8,988
Minimum
Business Combination [Line Items]
Estimated useful life of aircraft (in years)	25 years
Maximum
Business Combination [Line Items]
Estimated useful life of aircraft (in years)	30 years
Other Acquisitions
Business Combination [Line Items]
Acquisition of businesses, net of cash acquired	$ 285	314
GOODWILL	126	182
Other intangible assets	$ 90	$ 116
Goodwill and Intangible Assets, Deductible For Tax Purposes, Term	15 years	15 years
Amount of goodwill expected to be tax deductible	$ 126	$ 49
Business acquisition, intangible assets, expected tax deductible amount	$ 90	$ 22

ACQUISITIONS - Simmonds Precision Products, Inc. (Details) - USD ($) $ in Millions		12 Months Ended
	Oct. 06, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Business Combination [Line Items]
Acquisition of businesses, net of cash acquired		$ 419	$ 2,347	$ 762
Simmonds Precision Products, Inc. \| Subsequent Event
Business Combination [Line Items]
Acquisition of businesses, net of cash acquired	$ 757

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

DEBT - Issuance of $500 million of Senior Secured Notes due 2034 (Details) - USD ($) $ in Millions	Sep. 30, 2025	Aug. 19, 2025
Debt Instrument [Line Items]
Debt instrument, face amount	$ 29,236
6.250% secured notes due 2034 (“2034 Secured Notes”) \| Secured Debt
Debt Instrument [Line Items]
Debt instrument, face amount		$ 500
Issuance price of principal amount, percentage		100.00%
Interest rate	6.25%	6.25%
Debt issuance costs		$ 5

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Notional Amounts (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 15	$ 57
Derivative Liability, Fair Value, Gross Liability	3	10
Interest Rate Cap
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	20
Derivative Liability, Fair Value, Gross Liability	0	1
Interest Rate Collar
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	7	3
Derivative Liability, Fair Value, Gross Liability	3	8
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	8	34
Derivative Liability, Fair Value, Gross Liability	$ 0	$ 1

- Definition

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References + Details

- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References + Details

SEGMENTS - Geographic Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 8,831	$ 7,940	$ 6,585
Long-Lived Assets	1,644	1,549	1,319
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	5,535	5,032	4,265
Long-Lived Assets	1,339	1,273	1,063
Non-US
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	3,296	2,908	2,320
Long-Lived Assets	$ 305	$ 276	$ 256

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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+ Details

DEBT - Government Refundable Advances (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Government Refundable Advances
Debt Instrument [Line Items]
Government refundable advances	$ 12.0	$ 17.0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

PROPERTY, PLANT AND EQUIPMENT (Tables)

12 Months Ended

Sep. 30, 2025

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, plant and equipment consist of the following (in millions):


	September 30, 2025		September 30, 2024
Land and improvements	$	192	$	186
Buildings and improvements	794		733
Machinery, equipment and other	1,621		1,445
Construction-in-progress	163		141
Total	2,770		2,505
Accumulated depreciation	(1,191)		(1,017)
Property, plant and equipment—Net	$	1,579	$	1,488

SEGMENTS (Tables)

12 Months Ended

Sep. 30, 2025

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

The following table sets forth, for the periods indicated, certain financial information by reportable segment, which includes a reconciliation of EBITDA As Defined to consolidated income from continuing operations before income taxes (in millions):


	Fiscal Year Ended September 30, 2025
	Power & Control		Airframe		Non-aviation	Total
Net sales to external customers
Commercial and non-aerospace OEM	$	926	$	1,180		$	2,106
Commercial and non-aerospace aftermarket	1,360		1,444			2,804
Defense	2,273		1,488			3,761
Non-aviation	—		—		160	160
Net Sales	4,559		4,112		160	8,831
Less:
Other segment expenses (1)	1,964		1,902		93
Total segment EBITDA As Defined	2,595		2,210		67	4,872
Less: Unallocated corporate EBITDA As Defined						112
Depreciation and amortization expense						367
Interest expense-net						1,572
Acquisition transaction and integration-related expenses						42
Non-cash stock and deferred compensation expense						157
Refinancing costs						11
Other, net						(18)
Income from continuing operations before income taxes						$	2,629

(1)Primarily represents cost of sales, selling expenses, general and administrative expenses, research and development, and miscellaneous income or expense. Excludes depreciation and amortization; non-cash stock and deferred compensation expense; foreign currency transaction losses; acquisition transaction and integration-related expenses and payroll withholding taxes related to dividend equivalent payments.


	Fiscal Year Ended September 30, 2024
	Power & Control		Airframe		Non-aviation	Total
Net sales to external customers
Commercial and non-aerospace OEM	$	841	$	1,280		$	2,121
Commercial and non-aerospace aftermarket	1,218		1,290			2,508
Defense	1,907		1,239			3,146
Non-aviation	—		—		165	165
Net Sales	3,966		3,809		165	$	7,940
Less:
Other segment expenses (1)	1,715		1,847		99
Total segment EBITDA As Defined	2,251		1,962		66	4,279
Less: Unallocated corporate EBITDA As Defined						106
Depreciation and amortization expense						312
Interest expense-net						1,286
Acquisition transaction and integration-related expenses						70
Non-cash stock and deferred compensation expense						217
Refinancing costs						58
Other, net						15
Income from continuing operations before income taxes						$	2,215


	Fiscal Year Ended September 30, 2023
	Power & Control		Airframe		Non-aviation	Total
Net sales to external customers
Commercial and non-aerospace OEM	$	696	$	989		$	1,685
Commercial and non-aerospace aftermarket	1,074		1,112			2,186
Defense	1,569		993			2,562
Non-aviation	—		—		152	152
Net Sales	3,339		3,094		152	$	6,585
Less:
Other segment expenses (1)	1,459		1,547		95
Total segment EBITDA As Defined	1,880		1,547		57	3,484
Less: Unallocated corporate EBITDA As Defined						89
Depreciation and amortization expense						268
Interest expense-net						1,164
Acquisition transaction and integration-related expenses						18
Non-cash stock and deferred compensation expense						157
Refinancing costs						56
Other, net						16
Income from continuing operations before income taxes						$	1,716

Assets, Capital Expenditures and Depreciation and Amortization by Segment


	September 30, 2025
	Power & Control	Airframe	Non-aviation	Corporate (1)	Total
Total assets	9,859	10,267	202	2,581	22,909
Capital expenditures	108	103	9	2	222
Depreciation and amortization	180	181	6	—	367

(1)Corporate consists of our corporate offices and does not constitute an operating segment. These amounts are included to reconcile to total consolidated assets, capital expenditures and depreciation and amortization, respectively.


	September 30, 2024
	Power & Control	Airframe	Non-aviation	Corporate (1)	Total
Total assets	9,180	10,045	193	6,168	25,586
Capital expenditures	90	73	2	—	165
Depreciation and amortization	133	172	6	1	312


	September 30, 2023
	Power & Control	Airframe	Non-aviation	Corporate (1)	Total
Total assets	7,356	8,972	193	3,449	19,970
Capital expenditures	67	65	6	1	139
Depreciation and amortization	110	152	5	1	268

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas

Geographic Area Information

Net sales are measured based on the geographic destination of sales. Long-lived assets consist of property, plant and equipment-net and operating lease right-of-use assets. Net sales and long-lived assets of individual countries outside of the United States are not material.

The following table presents net sales by geographic area (in millions):


	Fiscal Years Ended September 30,
	2025		2024		2023
Net sales
United States	$	5,535	$	5,032	$	4,265
Foreign Countries	3,296		2,908		2,320
	$	8,831	$	7,940	$	6,585

The following table presents long-lived assets by geographic area (in millions):


	September 30, 2025		September 30, 2024		September 30, 2023
Long-lived assets
United States	$	1,339	$	1,273	$	1,063
Foreign Countries	305		276		256
	$	1,644	$	1,549	$	1,319

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Accrued Environmental Loss Contingencies, Current	$ 5	$ 5
Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration]	Accrued and other current liabilities	Accrued and other current liabilities
Accrued Environmental Loss Contingencies, Noncurrent	$ 33	$ 36
Environmental Loss Contingency, Noncurrent, Statement of Financial Position [Extensible Enumeration]	OTHER NON-CURRENT LIABILITIES	OTHER NON-CURRENT LIABILITIES

DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Interest Rate Derivatives (Details) $ in Millions	Sep. 30, 2025 USD ($)
3.2188% Interest rate swap, effective September 30, 2025 and maturing September 30, 2027
Derivative [Line Items]
Derivative, Notional Amount	$ 700
Derivative, Basis Spread on Variable Rate	3.22%
3.1075% Interest rate swap, effective September 30, 2027 and maturing September 30, 2029
Derivative [Line Items]
Derivative, Notional Amount	$ 125
Derivative, Basis Spread on Variable Rate	3.11%
3.1170% Interest rate swap, effective September 30, 2027 and maturing September 30, 2029
Derivative [Line Items]
Derivative, Notional Amount	$ 1,025
Derivative, Basis Spread on Variable Rate	3.12%
3.1355% Interest rate swap, effective September 30, 2027 and maturing September 30, 2029
Derivative [Line Items]
Derivative, Notional Amount	$ 900
Derivative, Basis Spread on Variable Rate	3.14%
2.00%-3.50% Interest rate collar, effective March 31, 2025 and Maturing September 30, 2026
Derivative [Line Items]
Derivative, Notional Amount	$ 1,100
2.00%-3.50% Interest rate collar, effective March 31, 2025 and Maturing September 30, 2026 \| Minimum
Derivative [Line Items]
Derivative, Variable Interest Rate	2.00%
2.00%-3.50% Interest rate collar, effective March 31, 2025 and Maturing September 30, 2026 \| Maximum
Derivative [Line Items]
Derivative, Variable Interest Rate	3.50%
2.00%-3.50% Interest rate collar, effective September 30, 2025 and Maturing September 30, 2026
Derivative [Line Items]
Derivative, Notional Amount	$ 500
2.00%-3.50% Interest rate collar, effective September 30, 2025 and Maturing September 30, 2026 \| Minimum
Derivative [Line Items]
Derivative, Variable Interest Rate	2.00%
2.00%-3.50% Interest rate collar, effective September 30, 2025 and Maturing September 30, 2026 \| Maximum
Derivative [Line Items]
Derivative, Variable Interest Rate	3.50%
2.50-4.50% Interest rate collar, effective September 30, 2025 and maturing September 30, 2027
Derivative [Line Items]
Derivative, Notional Amount	$ 1,338
2.50-4.50% Interest rate collar, effective September 30, 2025 and maturing September 30, 2027 \| Minimum
Derivative [Line Items]
Derivative, Variable Interest Rate	2.50%
2.50-4.50% Interest rate collar, effective September 30, 2025 and maturing September 30, 2027 \| Maximum
Derivative [Line Items]
Derivative, Variable Interest Rate	4.50%
2.00-3.91% Interest rate collar, effective September 30, 2025 and maturing September 30, 2027
Derivative [Line Items]
Derivative, Notional Amount	$ 700
2.00-3.91% Interest rate collar, effective September 30, 2025 and maturing September 30, 2027 \| Minimum
Derivative [Line Items]
Derivative, Variable Interest Rate	3.91%
2.00-3.91% Interest rate collar, effective September 30, 2025 and maturing September 30, 2027 \| Maximum
Derivative [Line Items]
Derivative, Variable Interest Rate	2.00%
2.50-4.50% Interest rate collar, effective September 30, 2026 and maturing September 30, 2027
Derivative [Line Items]
Derivative, Notional Amount	$ 1,550
2.50-4.50% Interest rate collar, effective September 30, 2026 and maturing September 30, 2027 \| Minimum
Derivative [Line Items]
Derivative, Variable Interest Rate	2.50%
2.50-4.50% Interest rate collar, effective September 30, 2026 and maturing September 30, 2027 \| Maximum
Derivative [Line Items]
Derivative, Variable Interest Rate	4.50%
2.211-4.25% Interest rate collar, effective September 30, 2027 and maturing September 30, 2029
Derivative [Line Items]
Derivative, Notional Amount	$ 2,050
2.211-4.25% Interest rate collar, effective September 30, 2027 and maturing September 30, 2029 \| Minimum
Derivative [Line Items]
Derivative, Variable Interest Rate	2.21%
2.211-4.25% Interest rate collar, effective September 30, 2027 and maturing September 30, 2029 \| Maximum
Derivative [Line Items]
Derivative, Variable Interest Rate	4.25%

INVENTORIES (Tables)

12 Months Ended

Sep. 30, 2025

Inventory Disclosure [Abstract]

Schedule of Inventory

Inventories consist of the following (in millions):


	September 30, 2025		September 30, 2024
Raw materials and purchased component parts	$	1,522	$	1,314
Work-in-progress	555		508
Finished goods	288		290
Total	2,365		2,112
Reserves for excess and obsolete inventory	(270)		(236)
Inventories—Net	$	2,095	$	1,876

Insider Trading Policies and Procedures	12 Months Ended
Insider Trading Policies and Procedures	Sep. 30, 2025
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

ACQUISITIONS - Raptor Scientific (Details) - USD ($) $ in Millions		12 Months Ended
	Jul. 31, 2024	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Business Combination [Line Items]
Acquisition of businesses, net of cash acquired		$ 419	$ 2,347	$ 762
GOODWILL		10,612	$ 10,419	$ 8,988
Raptor Scientific
Business Combination [Line Items]
Acquisition of businesses, net of cash acquired	$ 646
GOODWILL		365
Other intangible assets		264
Amount of goodwill expected to be tax deductible		350
Business acquisition, intangible assets, expected tax deductible amount		$ 251
Goodwill and Intangible Assets, Deductible For Tax Purposes, Term	15 years

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 2,074	$ 1,715	$ 1,299
Less: Net income attributable to noncontrolling interests	0	(1)	(1)
Net income attributable to TD Group	2,074	1,714	1,298
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment, net of tax	58	181	137
Unrealized (losses) gains on derivatives	(23)	(124)	20
Pension and post-retirement benefit plans adjustment	(3)	(1)	12
Other comprehensive income, net of tax, attributable to TD Group	32	56	169
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO TD GROUP	$ 2,106	$ 1,770	$ 1,467

ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Accumulated Other Comprehensive Income (Loss), Net of Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (6,283)	$ (1,978)	$ (3,766)
Other comprehensive income, net of tax, attributable to TD Group	32	56	169
Ending balance	(9,679)	(6,283)	(1,978)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax	8	(37)	6
Pension Liability Adjustments, Net	0		0
Cash Flow Hedging \| Designated as Hedging Instrument \| Net Sales
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	(1)	(3)
Derivative, Gain (Loss) on Derivative, Tax Expense (Benefit)	(1)	(1)
Cash Flow Hedging \| Designated as Hedging Instrument \| Interest Expense, Net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	57	106
Derivative, Gain (Loss) on Derivative, Tax Expense (Benefit)	(18)	(33)
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(42)	(98)	(267)
Other comprehensive income, net of tax, attributable to TD Group	32	56
Ending balance	(10)	(42)	(98)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	19	143
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax	(23)	(124)
Ending balance	(4)	19	143
Defined benefit pension plan activity (3)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	1	2
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(3)	(1)
Ending balance	(2)	1	2
Currency translation adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(62)	(243)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	58	181
Ending balance	$ (4)	$ (62)	$ (243)

DEBT - Obligations under Finance Leases (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Debt Instrument [Line Items]
Finance lease obligations	$ 284.0	$ 262.0
Finance Lease Obligations
Debt Instrument [Line Items]
Finance lease obligations	$ 284.0	$ 262.0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
OPERATING ACTIVITIES:
Net income	$ 2,074	$ 1,715	$ 1,299
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	163	149	129
Amortization of intangible assets and product certification costs	204	163	139
Amortization of debt issuance costs, original issue discount and premium	38	40	41
Amortization of inventory step-up	10	21	2
Amortization of loss contract reserves	(51)	(35)	(34)
Refinancing costs	11	58	56
Gain on sale of businesses, net	(10)	(11)	0
Non-cash stock and deferred compensation expense	157	217	157
Deferred income taxes	(10)	10	3
Foreign currency exchange losses	10	20	14
Gain on settlement of the Esterline Retirement Plan (the “ERP”)	0	0	(9)
Cash refund for the ERP settlement, net	0	0	9
Changes in assets/liabilities, net of effects from acquisitions and sales of businesses:
Trade accounts receivable	(212)	(84)	(212)
Inventories	(156)	(104)	(261)
Income taxes (receivable) payable	(94)	(62)	168
Other assets	(55)	(60)	(44)
Accounts payable	38	(11)	12
Accrued interest	23	60	(45)
Accrued and other liabilities	(102)	(41)	(49)
Net cash provided by operating activities	2,038	2,045	1,375
INVESTING ACTIVITIES:
Capital expenditures	(222)	(165)	(139)
Acquisition of businesses, net of cash acquired	(419)	(2,347)	(762)
Other investing transactions, net	46	71	1
Net cash used in investing activities	(595)	(2,441)	(900)
FINANCING ACTIVITIES:
Proceeds from exercise of stock options	166	245	215
Dividends and dividend equivalent payments	(9,629)	(2,038)	(38)
Repurchases of common stock	(500)	0	0
Proceeds from issuance of senior secured notes, net	494	7,373	3,504
Repayments of senior secured notes	0	(4,400)	(1,122)
Proceeds from issuance of senior subordinated notes, net	4,598	0	0
Repayments of senior subordinated notes, net	(2,650)	(550)	(1,459)
Proceeds from trade receivable securitization facility, net	238	137	0
Proceeds from term loans, net	6,015	6,815	6,238
Repayment on term loans	3,622	4,403	7,334
Financing costs and other, net	(10)	(8)	(20)
Net cash (used in) provided by financing activities	(4,900)	3,171	(16)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	4	14	12
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(3,453)	2,789	471
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	6,261	3,472	3,001
CASH AND CASH EQUIVALENTS, END OF PERIOD	2,808	6,261	3,472
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid during the period for interest, net	1,481	1,158	1,160
Cash paid during the period for income taxes, net of refunds	$ 640	$ 539	$ 260

VALUATION AND QUALIFYING ACCOUNTS

12 Months Ended

Sep. 30, 2025

SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]

VALUATION AND QUALIFYING ACCOUNTS

TRANSDIGM GROUP INCORPORATED

VALUATION AND QUALIFYING ACCOUNTS

FOR THE FISCAL YEARS ENDED SEPTEMBER 30, 2025, 2024, AND 2023

(Amounts in millions)


Column A	Column B		Column C				Column D		Column E
	Balance at Beginning of Period		Additions				Divestitures & Deductions from Reserve (1)		Balance at End of Period
Description			Charged to Costs and Expenses		Acquisitions & Purchase Price Adjustments
Year Ended September 30, 2025
Allowance for uncollectible accounts	$	32	$	4	$	—	$	(11)	$	25
Inventory valuation reserves	236		51		2		(19)		270
Valuation allowance for deferred tax assets	318		138		—		—		456
Year Ended September 30, 2024
Allowance for uncollectible accounts	$	31	$	3	$	—	$	(2)	$	32
Inventory valuation reserves	209		35		11		(19)		236
Valuation allowance for deferred tax assets	227		91		—		—		318
Year Ended September 30, 2023
Allowance for uncollectible accounts	$	35	$	4	$	—	$	(8)	$	31
Inventory valuation reserves	196		20		—		(7)		209
Valuation allowance for deferred tax assets	137		90		—		—		227

(1)The amounts in this column represent the impact from divestitures, charge-offs net of recoveries and the impact of foreign currency translation adjustments.

REVENUE RECOGNITION (Tables)

12 Months Ended

Sep. 30, 2025

Revenue Recognition [Abstract]

Contract with Customer, Asset and Liability


	September 30, 2025		September 30, 2024
Contract assets, current (1)	$	280	$	270
Contract assets, non-current (2)	94		31
Total contract assets	374		301
Contract liabilities, current (3)	143		168
Contract liabilities, non-current (4)	7		9
Total contract liabilities	150		177
Net contract assets	$	224	$	124

(1)Included in prepaid expenses and other on the consolidated balance sheets.

(2)Included in other non-current assets on the consolidated balance sheets.

(3)Included in accrued and other current liabilities on the consolidated balance sheets.

(4)Included in other non-current liabilities on the consolidated balance sheets.

INCOME TAXES

12 Months Ended

Sep. 30, 2025

Income Tax Disclosure [Abstract]

INCOME TAXES

The Company’s income from continuing operations before income taxes includes the following components for the periods shown below (in millions):


	Fiscal Years Ended September 30,
	2025		2024		2023
United States	$	2,119	$	1,800	$	1,413
Foreign	510		415		303
	$	2,629	$	2,215	$	1,716

The Company’s income tax provision (benefit) on income from continuing operations consists of the following for the periods shown below (in millions):


	Fiscal Years Ended September 30,
	2025		2024		2023
Current
Federal	$	420	$	354	$	276
State	45		38		41
Foreign	100		98		97
	565		490		414
Deferred
Federal	(32)		(6)		28
State	1		7		11
Foreign	21		9		(36)
	(10)		10		3
	$	555	$	500	$	417

A reconciliation of the federal statutory income tax rate to the effective income tax rate for the periods shown below is as follows:


	Fiscal Years Ended September 30,
	2025		2024		2023
Federal statutory income tax rate	21.0	%	21.0	%	21.0	%
Changes in valuation allowances impacting results	3.7	%	4.0	%	5.3	%
State and local income taxes, net of federal benefit	0.9	%	1.3	%	1.7	%
Foreign-derived intangible income	(1.6)	%	(1.2)	%	(1.2)	%
Stock-based compensation	(2.9)	%	(3.6)	%	(2.3)	%
Other—net	—	%	1.1	%	(0.2)	%
Effective income tax rate	21.1	%	22.6	%	24.3	%

The components of the deferred taxes consist of the following (in millions):


	September 30, 2025		September 30, 2024
Deferred tax assets (liabilities):
Intangible assets	$	(1,012)	$	(1,008)
Property, plant and equipment	(99)		(101)
Interest expense limitation	419		279
Employee benefits	131		115
Inventories	99		90
Capitalized research and development costs	86		73
Net operating losses	59		52
Other	14		52
Total	(303)		(448)
Add: Valuation allowance	(456)		(318)
Total net deferred tax assets (liabilities)	$	(759)	$	(766)

At September 30, 2025, the Company has state net operating loss carryforwards of approximately $780 million, German net operating loss carryforwards of $66 million and United Kingdom net operating loss carryforwards of approximately $93 million that expire in various fiscal years from 2026 to 2045. The Company has U.S. and non-U.S. tax credit carryforwards of $9 million that expire beginning in fiscal year 2026.

The deferred tax assets for the interest expense limitation, net operating losses, and tax credit carryforwards are reduced by a valuation allowance for the amount of such assets that the Company believes will not be realized.

With limited exception, no provision has been made for income taxes on undistributed earnings of foreign subsidiaries of approximately $30 million at September 30, 2025, since it is the Company’s intention to indefinitely reinvest such undistributed earnings. The cash that is permanently reinvested is typically used to expand operations either organically or through acquisitions. It is not practicable to estimate the additional taxes that would be payable on the remittance of such earnings. We have provided for taxes in jurisdictions in which we are not considered indefinitely reinvested, however, such amounts are not significant.

The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction and various state, local and foreign jurisdictions. The Company is no longer subject to U.S. federal examinations for years before fiscal 2018. The Company is currently under examination for its federal income taxes in Canada for fiscal years 2013 through 2019, in France for fiscal years 2020 through 2022, and in Germany for fiscal years 2017 through 2019. In addition, the Company is subject to state income tax examinations for fiscal years 2015 and later.

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in millions):


	2025		2024
Balance at October 1	$	14	$	17

Additions based on tax positions related to the prior year	7		1
Additions based on tax positions related to the current year	2		—
Reductions based on tax positions related to the prior year	—		—
Settlement with tax authorities	—		(3)
Lapse in statute of limitations	—		(1)
Balance at September 30	$	23	$	14

Unrecognized tax benefits at September 30, 2025 and 2024, the recognition of which would have an effect on the effective tax rate for each fiscal year, amounted to $23 million and $14 million, respectively. The Company classifies all income tax-related interest and penalties as income tax expense, which were not significant for the years ended September 30, 2025 and 2024. As of September 30, 2025 and 2024, the Company accrued $5 million and $4 million, respectively, for the potential payment of interest and penalties. Within the next twelve months, it is reasonably possible that unrecognized tax benefits could be reduced by approximately $2 million resulting from the resolution or closure of tax examinations. Any increase in the amount of unrecognized tax benefits within the next twelve months is not expected to be material.

On July 4, 2025, H.R. 1, commonly referred to as the One Big Beautiful Bill Act (the “Act”) was signed into law. It contains a broad range of tax reform provisions affecting businesses. The majority of these provisions will impact us starting in fiscal year 2027. We continue to evaluate the future effects of the Act on our effective tax rate and cash tax position. The impact of the legislation on our operating results for the year ended September 30, 2025 was not material.

- Definition

The entire disclosure for income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477617/942-740-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478822/944-740-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
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-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 5: http://www.xbrl.org/2003/role/exampleRef
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-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 12C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12C

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12B
-Publisher FASB
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 270
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-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477891/740-270-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-13

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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-Section S99
-Paragraph 1
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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-URI https://asc.fasb.org/740/tableOfContent

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-14

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-21

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

INVENTORIES - Schedule of Inventories (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Inventory Disclosure [Abstract]
Raw materials and purchased component parts	$ 1,522	$ 1,314
Work-in-progress	555	508
Finished goods	288	290
Total	2,365	2,112
Reserves for excess and obsolete inventory	(270)	(236)
Inventories—Net	$ 2,095	$ 1,876

GOODWILL AND INTANGIBLE ASSETS - Schedule of Finite-Lived Assets, Future Amortization (Details) $ in Millions	Sep. 30, 2025 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 203
Finite-Lived Intangible Assets, Amortization Expense, Year Two	187
Finite-Lived Intangible Assets, Amortization Expense, Year Three	179
Finite-Lived Intangible Assets, Amortization Expense, Year Four	178
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 170

INCOME TAXES - Components of Deferred Taxes (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Intangible assets	$ (1,012)	$ (1,008)
Property, plant and equipment	(99)	(101)
Interest expense limitation	419	279
Employee benefits	131	115
Inventories	99	90
Capitalized research and development costs	86	73
Net operating losses	59	52
Other	14	52
Total deferred tax liabilities	(303)	(448)
Add: Valuation allowance	(456)	(318)
Total net deferred tax liabilities	$ (759)	$ (766)

LEASES - Components of Lease Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Lessee, Lease, Description [Line Items]
Lease, Cost	$ 57	$ 50
Operating Expense
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	23	22
Cost of Sales
Lessee, Lease, Description [Line Items]
Finance Lease, Right-of-Use Asset, Amortization	15	12
Interest Expense
Lessee, Lease, Description [Line Items]
Finance Lease, Interest Expense	$ 19	$ 16

INVENTORIES

12 Months Ended

Sep. 30, 2025

Inventory Disclosure [Abstract]

INVENTORIES

Inventories consist of the following (in millions):


	September 30, 2025		September 30, 2024
Raw materials and purchased component parts	$	1,522	$	1,314
Work-in-progress	555		508
Finished goods	288		290
Total	2,365		2,112
Reserves for excess and obsolete inventory	(270)		(236)
Inventories—Net	$	2,095	$	1,876

STOCK-BASED COMPENSATION

12 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

The Company’s equity compensation plans are designed to assist the Company in attracting, retaining, motivating and rewarding key employees, directors or consultants, and promoting the creation of long-term value for stockholders by closely aligning the interests of these individuals with those of the Company’s stockholders. The Company’s equity compensation plans provide for the granting of stock options.

Non-cash stock compensation expense recognized by the Company during the fiscal years ended September 30, 2025, 2024 and 2023 was $152 million, $188 million and $135 million, respectively. The related tax benefit for the fiscal years ended September 30, 2025, 2024 and 2023 was $24 million, $24 million and $15 million, respectively. Of the non-cash stock compensation expense recorded in fiscal 2025, 2024 and 2023, $150 million, $134 million and $112 million was recorded as a component of additional paid in capital and less than $2 million, $54 million and $23 million was recorded as a component of other non-current liabilities. The liability awards relate to stock options granted between fiscal 2017 to fiscal 2020 from the 2014 stock option plan to certain employees in lieu of these individuals receiving salary and bonus compensation paid in cash. The vesting of the stock options are subject to the achievement of the same operating performance goals as other grants. The liability is remeasured each reporting period based on the market value of our common shares on the last day of the reported period. The other non-current liabilities related to stock-based compensation was $102 million as of September 30, 2025 and 2024.

The weighted-average grant date fair value of options granted during the fiscal years ended September 30, 2025, 2024 and 2023 was $549.03, $397.31 and $251.73, respectively. The total fair value of options vested during fiscal years ended September 30, 2025, 2024 and 2023 was $107 million, $97 million and $80 million, respectively.

Compensation expense is recognized based upon probability assessments of awards that are expected to vest in future periods, adjusted for expected forfeitures. Such probability assessments are subject to revision and, therefore, unrecognized compensation expense is subject to future changes in estimate. As of September 30, 2025, there was approximately $208 million of total unrecognized compensation expense related to non-vested awards expected to vest, which is expected to be recognized over a weighted-average period of 1.8 years.

The fair value of the Company’s employee stock options was estimated at the date of grant or modification using a Black-Scholes option-pricing model with the following weighted average assumptions for all options granted during the fiscal years ended:


	Fiscal Years Ended September 30,
	2025	2024	2023
Risk-free interest rate	4.0% to 4.5%	4.1% to 4.7%	3.5% to 4.2%
Expected life of options	6.5 years	6.5 years	6.5 years
Expected dividend yield of stock	—	—	—
Expected volatility of stock	32.5%	33.5%	32.5%

The risk-free interest rate is based upon the U.S. Treasury bond rates with a term similar to the expected life of the award as of the grant date or modification date. The average expected life of stock-based awards is based on the Company’s actual historical exercise experience. The Company uses actual historical changes in the market value of its stock to calculate the volatility assumption as it is management’s belief that this is the best indicator of future volatility. The Company estimates stock option forfeitures based on historical data. The total number of stock options expected to vest is adjusted by actual and estimated forfeitures. Changes to the actual and estimated forfeitures will result in a cumulative adjustment in the period of change. Notwithstanding the special cash dividends declared and paid from time to time, the Company historically has not declared and paid regular cash dividends and does not anticipate declaring and paying regular cash dividends in future periods. Furthermore, since vested options under the Company’s equity compensation plans are entitled to participate in dividend equivalents (refer to “Dividends and Dividend Equivalent Plans” section below) upon declaration of a special dividend, no expected dividend yield is assumed.

2019 Stock Option Plan

In August 2019, the Board of Directors of TD Group adopted a new stock option plan, which was subsequently approved by stockholders on October 3, 2019. The 2019 stock option plan permits TD Group to award stock options to our key employees, directors or consultants. The total number shares of TD Group common stock reserved for issuance or delivery under the 2019 stock option plan is 4,000,000, subject to adjustment in the event of any stock dividend or split, reorganization, recapitalization, merger, share exchange or any other similar corporate transaction or event.

Performance Vested Stock Options – Generally all of the options granted through September 30, 2025 under the 2019 stock option plan have been pursuant to an equity incentive program adopted by the Company in 2008. Under the 2008 equity incentive program, generally all of the options granted will vest based on the Company’s achievement of established operating performance goals. The following table summarizes the activity, pricing and other information for the Company’s performance vested stock-based award activity during the fiscal year ended September 30, 2025:


	Number of Options	Weighted-Average Exercise Price Per Option		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding at September 30, 2024	561,109	$	795.95
Granted	346,664	1,316.43
Exercised	(26,420)	656.47
Forfeited	(121,745)	909.08
Expired	—	—
Outstanding at September 30, 2025	759,608	$	1,020.20	8.4 years	$	226,226,455
Expected to vest	409,971	$	1,051.67	8.5 years	$	109,195,776
Exercisable at September 30, 2025	93,696	$	724.47	7.6 years	$	55,613,261

At September 30, 2025, there were 3,210,451 remaining shares available for award under TD Group’s 2019 stock option plan.

2014 Stock Option Plan

In July 2014, the Board of Directors of TD Group adopted the 2014 stock option plan, which was subsequently approved by stockholders on October 2, 2014. The 2014 stock option plan permitted TD Group to award stock options to our key employees, directors or consultants. The total number of shares of TD Group common stock reserved for issuance or delivery under the 2014 stock option plan was 5,000,000, subject to adjustment in the event of any stock dividend or split, reorganization, recapitalization, merger, share exchange or any other similar corporate transaction or event. The 2014 stock option plan expired on July 24, 2024 and no further shares are granted under the plan thereafter.

Performance Vested Stock Options – Generally all of the options granted through September 30, 2025 under the 2014 stock option plan have been pursuant to an equity incentive program adopted by the Company in 2008. Under the 2008 equity incentive program, generally all of the options granted will vest based on the Company’s achievement of established operating performance goals. The following table summarizes the activity, pricing and other information for the Company’s performance vested stock-based award activity during the fiscal year ended September 30, 2025:


	Number of Options	Weighted-Average Exercise Price Per Option		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding at September 30, 2024	3,779,503	$	466.18
Granted	—	—
Exercised	(462,368)	288.80
Forfeited	(86,209)	620.43
Expired	—	—
Outstanding at September 30, 2025	3,230,926	$	487.45	4.4 years	$	2,683,510,208
Expected to vest	478,730	$	670.73	7.1 years	$	309,877,142
Exercisable at September 30, 2025	2,429,832	$	376.64	3.6 years	$	2,287,395,248

2006 Stock Incentive Plan

In conjunction with the consummation of the Company’s initial public offering, a 2006 stock incentive plan was adopted by TD Group. In July 2008 and March 2011, the 2006 stock incentive plan was amended to increase the number of shares available for issuance thereunder. TD Group reserved 8,119,668 shares of its common stock for issuance to key employees, directors or consultants under the plan. The 2006 stock incentive plan expired on March 14, 2016 and no further shares are granted under the plan thereafter. At September 30, 2025, there were 1,450 options outstanding and exercisable under TD Group’s 2006 stock incentive plan.

The total intrinsic value of performance options exercised during the fiscal years ended September 30, 2025, 2024 and 2023 was $600 million, $794 million and $500 million, respectively.

Dividends and Dividend Equivalent Plans

Since August 5, 2022, pursuant to the Fourth Amended and Restated TransDigm Group Incorporated 2006 Stock Incentive Plan Dividend Equivalent Plan, the Amended and Restated 2014 Stock Option Plan Dividend Equivalent Plan and the 2019 Stock Option Plan Dividend Equivalent Plan, all of the vested options granted under the existing stock option plans, except for grants to the members of the Board of Directors, are entitled to certain dividend equivalent payments in the event of the declaration of a special dividend by the Company.

In fiscal 2025, the Company's Board of Directors authorized and declared $90.00 in special dividends on each outstanding share of common stock and cash dividend equivalent payments on eligible vested options outstanding under its stock option plans. The total cash payment in September 2025 was approximately $5,073 million in special dividends and $159 million in cash dividend equivalent payments.

Dividend equivalents on vested options were $208 million, $233 million and $38 million during the fiscal years ended September 30, 2025, 2024 and 2023, respectively. At September 30, 2025, there was $59 million recorded in accrued and other current liabilities and $76 million recorded in other non-current liabilities on the consolidated balance sheets related to future dividend equivalent payments.

FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Carrying Amounts and Fair Values of Financial Instruments

The following summarizes the carrying amounts and fair values of financial instruments (in millions):


		September 30, 2025				September 30, 2024
	Level	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Assets:
Cash and cash equivalents	1	$	2,808	$	2,808	$	6,261	$	6,261
Interest rate swap agreements (1)	2	3		3		34		34
Interest rate cap agreements (1)	2	—		—		20		20
Interest rate collar agreements (1)	2	4		4		—		—
Foreign currency forward exchange contracts (1)	2	—		—		3		3
Interest rate swap agreements (2)	2	5		5		—		—

Interest rate collar agreements (2)	2	3		3		3		3
Liabilities:
Interest rate swap agreements (3)	2	—		—		1		1
Interest rate cap agreements (3)	2	—		—		1		1
Foreign currency forward exchange contracts (3)	2	2		2		—		—


Interest rate collar agreements (4)	2	3		3		8		8
Short-term borrowings - trade receivable securitization facility (5)	2	724		724		486		486
Long-term debt, including current portion:
Term loans (5)	2	11,048		11,120		8,642		8,694
5.500% 2027 Notes (5)	1	—		—		2,641		2,637
2028 Secured Notes (5)	1	2,083		2,139		2,077		2,160
4.625% 2029 Notes (5)	1	1,195		1,175		1,194		1,160
2029 Secured Notes (5)	1	2,732		2,812		2,727		2,836
4.875% 2029 Notes (5)	1	747		739		746		729
2030 Secured Notes (5)	1	1,440		1,501		1,438		1,519
2031 Secured Notes (5)	1	986		1,041		984		1,058
2032 Secured Notes (5)	1	2,183		2,263		2,180		2,291
2033 Secured Notes (5)	1	1,488		1,517		1,486		1,521
6.375% 2033 Notes (5)	1	2,616		2,686		—		—
2034 Secured Notes (5)	1	495		514		—		—
6.750% 2034 Notes (5)	1	1,982		2,068		—		—
Government refundable advances	2	12		12		17		17
Finance lease obligations	2	284		284		262		262

(1)Included in prepaid expenses and other on the consolidated balance sheets.

(2)Included in other assets on the consolidated balance sheets.

(3)Included in accrued and other current liabilities on the consolidated balance sheets.

(4)Included in other non-current liabilities on the consolidated balance sheets.

(5)The carrying amount of the debt instrument is presented net of debt issuance costs and original issue discount. Refer to Note 10, “Debt,” for gross carrying amounts.

LEASES

12 Months Ended

Sep. 30, 2025

Leases [Abstract]

LEASES

The Company leases certain manufacturing facilities, offices, land, equipment and vehicles. Such leases, some of which are noncancellable and, in many cases, include renewals, expire at various dates. Such options to renew are included in the lease term when it is reasonably certain that the option will be exercised. The Company’s lease agreements typically do not contain any significant residual value guarantees or restrictive covenants, and payments within certain lease agreements are adjusted periodically for changes in an index or rate.

The Company determines if an arrangement is a lease at inception. Operating lease assets and liabilities are recognized at the commencement date of the lease based on the present value of lease payments over the lease term. Lease assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. The discount rate implicit within our leases is generally not determinable and therefore we determine the discount rate based on our incremental borrowing rate. The incremental borrowing rate for our leases is determined based on the lease term and the currency in which lease payments are made. The length of a lease term includes options to extend or terminate the lease when it is reasonably certain that the Company will exercise those options. The Company made an accounting policy election to not recognize lease assets or liabilities for leases with a term of twelve months or less. Additionally, when accounting for leases, the Company combines payments for leased assets, related services and other components of a lease.

The components of lease expense for the fiscal years ended September 30, 2025 and 2024 are as follows (in millions):


		Fiscal Years Ended September 30,
	Classification	2025		2024
Operating lease cost	Cost of sales or selling and administrative expenses	$	23	$	22
Finance lease cost:
Amortization of leased assets	Cost of sales	15		12
Interest on lease liabilities	Interest expense-net	19		16
Total lease cost		$	57	$	50

Supplemental cash flow information related to leases for the fiscal years ended September 30, 2025 and 2024 is as follows (in millions):


	Fiscal Years Ended September 30,
	2025		2024
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows from operating leases	$	23	$	21
Operating cash outflows from finance leases	16		14
Financing cash outflows from finance leases	7		6

Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$	25	$	21
Financing leases	25		83

Supplemental balance sheet information related to leases is as follows (in millions):


	Classification	September 30, 2025		September 30, 2024
Operating Leases
Operating lease right-of-use assets	Other non-current assets	$	65	$	61

Current operating lease liabilities	Accrued and other current liabilities	15		19
Long-term operating lease liabilities	Other non-current liabilities	51		43
Total operating lease liabilities		$	66	$	62

Finance Leases
Finance lease right-of-use assets, net	Property, plant and equipment-net	$	264	$	252

Current finance lease liabilities	Current portion of long-term debt	8		6
Long-term finance lease liabilities	Long-term debt	276		256
Total finance lease liabilities		$	284	$	262

As of September 30, 2025, the Company has the following remaining lease term and weighted average discount rates:


Weighted-average remaining lease term
Operating leases			6.4 years
Finance leases			19.8 years

Weighted-average discount rate
Operating leases			5.7%
Finance leases			7.0%

Maturities of lease liabilities at September 30, 2025 are as follows (in millions):


	Operating Leases		Finance Leases
2026	$	19	$	22
2027	16		26
2028	12		25
2029	9		25
2030	5		27
Thereafter	20		437
Total future minimum lease payments	81		562
Less: imputed interest	15		278
Present value of lease liabilities reported	$	66	$	284

DEBT - Schedule of Debt (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Aug. 19, 2025	May 20, 2025	Sep. 30, 2024
Debt Instrument [Line Items]
Debt Issuance Costs	$ (163.0)			$ (136.0)
Original Issue Discount	(66.0)			(51.0)
Short-term borrowings—trade receivable securitization facility	724.0			486.0
Gross Amount	29,520.0			24,581.0
Net Amount	29,291.0			24,394.0
Finance lease obligations	284.0			262.0
Current portion of long-term debt	124.0			98.0
Long-term Debt, Gross and Lease Obligation	29,395.0			24,482.0
Deferred Finance Costs, Excluding Current Maturities	(162.0)			(135.0)
Debt Instrument, Unamortized Discount, Excluding Current Maturities	(66.0)			(51.0)
LONG-TERM DEBT	29,167.0			24,296.0
Term loans
Debt Instrument [Line Items]
Debt Issuance Costs	(43.0)			(25.0)
Original Issue Discount	(33.0)			(35.0)
Gross Amount	11,124.0			8,702.0
Net Amount	$ 11,048.0			8,642.0
Secured Debt \| 6.750% secured notes due 2028 (“2028 Secured Notes”)
Debt Instrument [Line Items]
Interest rate	6.75%
Debt Issuance Costs	$ (11.0)			(15.0)
Original Issue Discount	(6.0)			(8.0)
Gross Amount	2,100.0			2,100.0
Net Amount	$ 2,083.0			2,077.0
Secured Debt \| 6.875% secured notes due 2030 (“2030 Secured Notes”)
Debt Instrument [Line Items]
Interest rate	6.875%
Debt Issuance Costs	$ (10.0)			(12.0)
Original Issue Discount	0.0			0.0
Gross Amount	1,450.0			1,450.0
Net Amount	$ 1,440.0			1,438.0
Secured Debt \| 6.375% secured notes due 2029 (“2029 Secured Notes”)
Debt Instrument [Line Items]
Interest rate	6.375%
Debt Issuance Costs	$ (17.0)			(22.0)
Original Issue Discount	(1.0)			(1.0)
Gross Amount	2,750.0			2,750.0
Net Amount	$ 2,732.0			2,727.0
Secured Debt \| 7.125% secured notes due 2031 (“2031 Secured Notes”)
Debt Instrument [Line Items]
Interest rate	7.125%
Debt Issuance Costs	$ (8.0)			(9.0)
Original Issue Discount	(6.0)			(7.0)
Gross Amount	1,000.0			1,000.0
Net Amount	$ 986.0			984.0
Secured Debt \| 6.625% secured notes due 2032 (“2032 Secured Notes”)
Debt Instrument [Line Items]
Interest rate	6.625%
Debt Issuance Costs	$ (17.0)			(20.0)
Original Issue Discount	0.0			0.0
Gross Amount	2,200.0			2,200.0
Net Amount	$ 2,183.0			2,180.0
Secured Debt \| 6.000% secured notes due 2033 (“2033 Secured Notes”)
Debt Instrument [Line Items]
Interest rate	6.00%
Debt Issuance Costs	$ (12.0)			(14.0)
Original Issue Discount	0.0			0.0
Gross Amount	1,500.0			1,500.0
Net Amount	1,488.0			1,486.0
Secured Debt \| 6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”)
Debt Instrument [Line Items]
Net Amount	$ 2,616.0			0.0
Secured Debt \| 6.250% secured notes due 2034 (“2034 Secured Notes”)
Debt Instrument [Line Items]
Interest rate	6.25%	6.25%
Debt Issuance Costs	$ (5.0)
Original Issue Discount	0.0
Gross Amount	500.0
Net Amount	495.0			0.0
Secured Debt \| 6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”)
Debt Instrument [Line Items]
Net Amount	$ 1,982.0			0.0
Senior Subordinated Notes \| 5.500% senior subordinated notes due 2027 (“5.500% 2027 Notes”)
Debt Instrument [Line Items]
Interest rate	5.50%
Debt Issuance Costs				(9.0)
Original Issue Discount				0.0
Gross Amount				2,650.0
Net Amount	$ 0.0			2,641.0
Senior Subordinated Notes \| 4.625% senior subordinated notes due 2029 (“4.625% 2029 Notes”)
Debt Instrument [Line Items]
Interest rate	4.625%
Debt Issuance Costs	$ (5.0)			(6.0)
Original Issue Discount	0.0			0.0
Gross Amount	1,200.0			1,200.0
Net Amount	$ 1,195.0			1,194.0
Senior Subordinated Notes \| 4.875% senior subordinated notes due 2029 (“4.875% 2029 Notes”)
Debt Instrument [Line Items]
Interest rate	4.875%
Debt Issuance Costs	$ (3.0)			(4.0)
Original Issue Discount	0.0			0.0
Gross Amount	750.0			750.0
Net Amount	$ 747.0			746.0
Senior Subordinated Notes \| 6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”)
Debt Instrument [Line Items]
Interest rate	6.375%		6.375%
Debt Issuance Costs	$ (14.0)
Original Issue Discount	(20.0)
Gross Amount	2,650.0
Net Amount	$ 2,616.0
Senior Subordinated Notes \| 6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”)
Debt Instrument [Line Items]
Interest rate	6.75%	6.75%
Debt Issuance Costs	$ (18.0)
Original Issue Discount	0.0
Gross Amount	2,000.0
Net Amount	1,982.0
Government Refundable Advances
Debt Instrument [Line Items]
Debt Issuance Costs	0.0			0.0
Original Issue Discount	0.0			0.0
Net Amount	12.0			17.0
Government refundable advances	12.0			17.0
Finance Lease Obligations
Debt Instrument [Line Items]
Debt Issuance Costs	0.0
Original Issue Discount	0.0
Finance lease obligations	284.0
Long-term Debt, Current Maturities
Debt Instrument [Line Items]
Debt Issuance Costs	(1.0)			(1.0)
Original Issue Discount	0.0			0.0
Less: current portion	125.0			99.0
Current portion of long-term debt	124.0			98.0
Finance Lease Obligations
Debt Instrument [Line Items]
Debt Issuance Costs				0.0
Original Issue Discount				0.0
Finance lease obligations	284.0			262.0
Asset-backed Securities
Debt Instrument [Line Items]
Short-term borrowings—trade receivable securitization facility, Gross	725.0			487.0
Debt Issuance Costs	(1.0)			(1.0)
Original Issue Discount	0.0			0.0
Short-term borrowings—trade receivable securitization facility	$ 724.0			$ 486.0

DERIVATIVES AND HEDGING ACTIVITIES (Tables)

12 Months Ended

Sep. 30, 2025

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Notional Amounts of Outstanding Derivative Positions

The tables below summarize the key terms of the swaps and collars as of September 30, 2025 (aggregated by effective date).

Interest rate swap agreements:

Aggregate Notional Amount (in millions)

Effective Date

Maturity Date

Conversion of Related Variable Rate Debt subject to Term SOFR to Fixed Rate of:

$700

9/30/2025

9/30/2027

3.22% plus applicable margin percentage

$125

9/30/2027

9/30/2029

3.11% plus applicable margin percentage

$1,025

9/30/2027

9/30/2029

3.12% plus applicable margin percentage

$900

9/30/2027

9/30/2029

3.14% plus applicable margin percentage

Interest rate collar agreements:

Aggregate Notional Amount (in millions)

Effective Date

Maturity Date

Offsets Variable Rate Debt Attributable to Fluctuations Below and Above:

$1,100

3/31/2025

9/30/2026

Three-month Term SOFR rate of 2.00% (floor) and 3.50% (cap)

$500

9/30/2025

9/30/2026

Three-month Term SOFR rate of 2.00% (floor) and 3.50% (cap)

$1,338

9/30/2025

9/30/2027

Three-month Term SOFR rate of 2.50% (floor) and 4.50% (cap)

$700

9/30/2025

9/30/2027

Three-month Term SOFR rate of 2.00% (floor) and 3.91% (cap)

$1,550

9/30/2026

9/30/2027

Three-month Term SOFR rate of 2.50% (floor) and 4.50% (cap)

$2,050

9/30/2027

9/30/2029

Three-month Term SOFR rate of 2.21% (floor) and 4.25% (cap)

Schedule of Interest Rate Derivatives


	September 30, 2025				September 30, 2024
	Asset		Liability		Asset		Liability
Interest rate cap agreement	$	—	$	—	$	20	$	1
Interest rate collar agreements	7		3		3		8
Interest rate swap agreements	8		—		34		1


Net derivatives as classified in the consolidated balance sheets (1)	$	15	$	3	$	57	$	10

(1)Refer to Note 11, “Fair Value Measurements,” for the consolidated balance sheets classification of the Company’s interest rate swap, cap and collar agreements.

SEGMENTS - Net Sales and EBITDA Defined by Segment to Consolidated Income Before Taxes Operations (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	$ 8,831	$ 7,940	$ 6,585
Earnings before interest taxes depreciation and amortization	112	106	89
Depreciation and amortization expense	367	312	268
Interest expense-net	1,572	1,286	1,164
Acquisition transaction and integration-related expenses	42	70	18
Non-cash stock and deferred compensation expense	157	217	157
Refinancing costs	11	58	56
Other, net	(18)	15	16
Income from continuing operations before income taxes	2,629	2,215	1,716
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	8,831	7,940	6,585
Earnings before interest taxes depreciation and amortization	4,872	4,279	3,484
Operating Segments \| Commercial and non-aerospace OEM
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	2,106	2,121	1,685
Operating Segments \| Commercial and non-aerospace aftermarket
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	2,804	2,508	2,186
Operating Segments \| Defense
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	3,761	3,146	2,562
Operating Segments \| Power & Control
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	4,559	3,966	3,339
Other segment expenses	1,964	1,715	1,459
Earnings before interest taxes depreciation and amortization	2,595	2,251	1,880
Depreciation and amortization expense	180	133	110
Operating Segments \| Power & Control \| Commercial and non-aerospace OEM
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	926	841	696
Operating Segments \| Power & Control \| Commercial and non-aerospace aftermarket
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	1,360	1,218	1,074
Operating Segments \| Power & Control \| Defense
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	2,273	1,907	1,569
Operating Segments \| Airframe
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	4,112	3,809	3,094
Other segment expenses	1,902	1,847	1,547
Earnings before interest taxes depreciation and amortization	2,210	1,962	1,547
Depreciation and amortization expense	181	172	152
Operating Segments \| Airframe \| Commercial and non-aerospace OEM
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	1,180	1,280	989
Operating Segments \| Airframe \| Commercial and non-aerospace aftermarket
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	1,444	1,290	1,112
Operating Segments \| Airframe \| Defense
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	1,488	1,239	993
Operating Segments \| Non-aviation
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	160	165	152
Other segment expenses	93	99	95
Earnings before interest taxes depreciation and amortization	67	66	57
Depreciation and amortization expense	$ 6	$ 6	$ 5

Insider Trading Arrangements	3 Months Ended	12 Months Ended
Insider Trading Arrangements	Sep. 30, 2025 shares	Sep. 30, 2025 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Joel Reiss [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		On August 12, 2025, Joel Reiss, the Company’s Co-Chief Operating Officer, entered into a new “Rule 10b5-1 trading arrangement” (as defined in Item 408 of Regulation S-K) for the sale of 65,600 shares of common stock issuable upon the exercise of vested options intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act, which Rule 10b5-1 trading arrangement is scheduled to begin on November 17, 2025 and terminate no later than October 30, 2026.
Name	Joel Reiss
Title	Co-Chief Operating Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	August 12, 2025
Expiration Date	October 30, 2026
Arrangement Duration	347 days
Aggregate Available	65,600	65,600

COMMITMENTS AND CONTINGENCIES	12 Months Ended
COMMITMENTS AND CONTINGENCIES	Sep. 30, 2025
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES During the ordinary course of business, the Company is from time to time threatened with, or may become a party to, legal actions and other proceedings such as product liability claims, employee claims, workers’ compensation claims and class action lawsuits. Insurance may cover some of the costs associated with these claims and proceedings. While the Company is currently involved in certain legal proceedings, it believes the results of these proceedings will not have a material adverse effect on its financial condition, results of operations, or cash flows. Environmental Liabilities – Our operations and facilities are subject to a number of federal, state, local and foreign environmental laws and regulations that govern, among other things, discharges of pollutants into the air and water, the generation, handling, storage and disposal of hazardous materials and wastes, the remediation of contamination and the health and safety of our employees. Environmental laws and regulations may require that the Company investigate and remediate the effects of the release or disposal of materials at sites associated with past and present operations. Certain facilities and third-party sites utilized by the Company have been identified as potentially responsible parties under the federal superfund laws and comparable state laws. The Company is currently involved in the investigation and remediation of a number of sites under applicable laws. Estimates of the Company’s environmental liabilities are based on current facts, laws, regulations and technology. These estimates take into consideration the Company’s prior experience and professional judgment of the Company’s environmental advisors. Estimates of the Company’s environmental liabilities are further subject to uncertainties regarding the nature and extent of site contamination, the range of remediation alternatives available, evolving remediation standards, imprecise engineering evaluations and cost estimates, the extent of corrective actions that may be required and the number and financial condition of other potentially responsible parties, as well as the extent of their responsibility for the remediation. Accordingly, as investigation and remediation proceed, it is likely that adjustments in the Company’s accruals will be necessary to reflect new information. The amounts of any such adjustments could have a material adverse effect on the Company’s results of operations or cash flows in a given period. Based on currently available information, however, the Company does not believe that future environmental costs in excess of those accrued with respect to sites for which the Company has been identified as a potentially responsible party are likely to have a material adverse effect on the Company’s financial condition or results of operations. Environmental liabilities are recorded when the liability is probable and the costs are reasonably estimable, which generally is not later than at completion of a feasibility study or when the Company has recommended a remedy or has committed to an appropriate plan of action. The Company also takes into consideration the estimated period of time in which payments will be required. The liabilities are reviewed periodically and, as investigation and remediation proceed, adjustments are made as necessary. Liabilities for losses from environmental remediation obligations do not consider the effects of inflation and anticipated expenditures are not discounted to their present value. The liabilities are not offset by possible recoveries from insurance carriers or other third parties, but do reflect anticipated allocations among potentially responsible parties at federal superfund sites or similar state-managed sites, third party indemnity obligations, and an assessment of the likelihood that such parties will fulfill their obligations at such sites. The Company’s consolidated balance sheets includes current environmental remediation obligations at both September 30, 2025 and 2024 of $5 million classified as a component of accrued and other current liabilities, respectively, and non-current environmental remediation obligations at September 30, 2025 and 2024 of $33 million and $36 million classified as a component of other non-current liabilities, respectively.

ACQUISITIONS - CPI's Electron Device Business (Details) - USD ($) $ in Millions		12 Months Ended
	Jun. 06, 2024	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Business Combination [Line Items]
Acquisition of businesses, net of cash acquired		$ 419	$ 2,347	$ 762
GOODWILL		10,612	$ 10,419	$ 8,988
CPI Electron Device Business
Business Combination [Line Items]
Acquisition of businesses, net of cash acquired	$ 1,386
GOODWILL		763
Other intangible assets		$ 509

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

ACQUISITIONS	12 Months Ended
ACQUISITIONS	Sep. 30, 2025
Business Combination [Abstract]
ACQUISITIONS	ACQUISITIONS Simmonds Precision Products, Inc. – On June 30, 2025, the Company entered into a definitive agreement to acquire all the outstanding stock of the Simmonds Precision Products, Inc. Business (“Simmonds”) of Goodrich Corporation from RTX Corporation for approximately $757 million in cash. On October 6, 2025, the acquisition was completed. The acquisition was financed through existing cash on hand. Simmonds, headquartered in Vergennes, Vermont, is a leading global designer and manufacturer of fuel & proximity sensing and structural health monitoring solutions for the aerospace and defense end markets. The Company’s products are highly engineered, proprietary components with significant aftermarket content and a strong presence across major aerospace and defense platforms. The operating results of Simmonds will be included within TransDigm's Power & Control segment. Servotronics, Inc. – On June 2, 2025, the Company launched a tender offer to acquire all the issued and outstanding stock of Servotronics, Inc. (“Servotronics”), at a price of $47.00 per share in cash. On July 1, 2025, the tender offer expired, resulting in all issued and outstanding stock of Servotronics being canceled and Servotronics becoming a wholly owned subsidiary of the Company. The total purchase price was approximately $133 million in cash, which was financed through existing cash on hand. Servotronics, headquartered in Elma, New York, is a leading global designer and manufacturer of servo controls and other advanced technology components for aerospace and defense applications. Its products are highly engineered, proprietary components with significant aftermarket content and a strong presence across major aerospace and defense platforms. The operating results of Servotronics are included within TransDigm's Power & Control segment. Based on the fair value of the assets acquired and liabilities assumed, $75 million of goodwill and $46 million of other intangible assets was recognized for the acquisition as of September 30, 2025, none of which is expected to be deductible for tax purposes. As of September 30, 2025, the measurement period (not to exceed one year) is open; therefore, the assets acquired and liabilities assumed are subject to adjustment until the end of the measurement period. Raptor Scientific – On July 31, 2024, the Company acquired all the outstanding stock of Raptor Scientific for approximately $646 million in cash. The acquisition was financed through existing cash on hand. Raptor Scientific is a leading global manufacturer of complex test and measurement solutions primarily serving the aerospace and defense end markets. Its products are highly engineered, proprietary components with significant aftermarket content and a strong presence across major aerospace and defense platforms. The operating results of Raptor Scientific are included within TransDigm's Airframe segment. Based on the fair value of the assets acquired and liabilities assumed, $365 million of goodwill and $264 million of other intangible assets was recognized for the acquisition. Of the $365 million of goodwill recognized for the acquisition, $350 million is deductible for tax purposes. Of the $264 million of other intangible assets recognized for the acquisition, $251 million is deductible for tax purposes. The goodwill and intangible assets are deductible over 15 years. CPI's Electron Device Business – On June 6, 2024, the Company acquired all the outstanding stock of the Electron Device Business of Communications & Power Industries (“CPI's Electron Device Business”) for approximately $1,386 million in cash. The acquisition was financed through existing cash on hand. CPI’s Electron Device Business is a leading global manufacturer of electronic components and subsystems primarily serving the aerospace and defense market. Its products are highly engineered, proprietary components with significant aftermarket content and a strong presence across major aerospace and defense platforms. The operating results of CPI’s Electron Device Business are included within TransDigm's Power & Control segment. Based on the fair value of the assets acquired and liabilities assumed, $763 million of goodwill and $509 million of other intangible assets was recognized for the acquisition, none of which is deductible for tax purposes. Other Acquisitions – For the fiscal year ended September 30, 2025, the Company completed a number of acquisitions consisting of substantially all of the assets and technical data rights of certain product lines or all the outstanding stock of certain businesses (collectively, referred to herein as the “Other Acquisitions”), each meeting the definition of a business, for a total aggregate purchase price of $285 million in cash. Each of the acquisitions was financed through existing cash on hand. The operating results of the acquisitions, which represent bolt-ons to existing TransDigm operating units, are presented within TransDigm's Power & Control or Airframe segment. The Company expects that all of the $126 million of goodwill and $90 million of other intangible assets recognized as of September 30, 2025 for the acquisitions will be deductible for tax purposes over 15 years. As of September 30, 2025, the measurement period (not to exceed one year) is open for certain Other Acquisitions; therefore, the assets acquired and liabilities assumed are subject to adjustment until the end of the respective measurement period. For the fiscal year ended September 30, 2024, the Company completed a number of Other Acquisitions for a total aggregate purchase price of $314 million in cash. Each of the acquisitions was financed through existing cash on hand. The operating results of the acquisitions, which represent bolt-ons to existing TransDigm operating units, are presented within TransDigm's Power & Control or Airframe segment. Of the $182 million of goodwill recognized for the acquisitions, $49 million is deductible for tax purposes over 15 years. Of the $116 million of other intangible assets recognized for the acquisitions, $22 million is deductible for tax purposes over 15 years. Pro forma net sales and results of operations for the acquisitions, had they occurred at the beginning of the fiscal years ended September 30, 2025 or September 30, 2024 are not material and, accordingly, are not provided. The acquisitions completed by the Company strengthen and expand the Company’s position to design, produce and supply highly engineered proprietary aerospace components in niche markets with significant aftermarket content and provide opportunities to create value through the application of our three core value-driven operating strategy (obtaining profitable new business, continually improving our cost structure, and providing highly engineered value-added products to customers). The purchase prices paid reflect the current EBITDA As Defined and cash flows, as well as the future EBITDA As Defined and cash flows expected to be generated by the businesses, which are driven in most cases by the recurring aftermarket consumption over the life of a particular aircraft, estimated to be approximately 25 to 30 years.

- Definition

The entire disclosure for business combination.

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+ Details

TRADE ACCOUNTS RECEIVABLE - Content Trade Accounts Receivable (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Receivables [Abstract]
Trade accounts receivable—gross	$ 1,642	$ 1,413
Allowance for uncollectible accounts	(25)	(32)
Trade accounts receivable—Net	$ 1,617	$ 1,381

DEBT - Trade Receivable Securitization Facility (Details) - Securitization Facility - USD ($) $ in Millions	1 Months Ended
	Sep. 30, 2025	Oct. 31, 2024	Jul. 11, 2025	Jul. 10, 2025	Sep. 30, 2024
Short-Term Debt [Line Items]
Maximum borrowing capacity			$ 725	$ 650
Proceeds from Lines of Credit	$ 75	$ 163
Long-Term Line of Credit	$ 725
Interest rate			1.35%	1.45%
Debt, Weighted Average Interest Rate	5.67%				6.73%

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References + Details

GOODWILL AND INTANGIBLE ASSETS - Schedule of Intangible Assets Acquired (Detail) $ in Millions	12 Months Ended
	Sep. 30, 2025 USD ($)
Intangible Asset, Acquired, Finite-Lived [Line Items]
Intangible assets subject to amortization	$ 125
intangible Assets, Acquired During the Period	136
Trademarks and trade names
Intangible Asset, Acquired, Finite-Lived [Line Items]
Intangible assets not subject to amortization	11
Technology
Intangible Asset, Acquired, Finite-Lived [Line Items]
Intangible assets subject to amortization	$ 71
Technology \| Minimum
Intangible Asset, Acquired, Finite-Lived [Line Items]
Amortization Period (in years)	10 years
Technology \| Maximum
Intangible Asset, Acquired, Finite-Lived [Line Items]
Amortization Period (in years)	20 years
Order backlog
Intangible Asset, Acquired, Finite-Lived [Line Items]
Intangible assets subject to amortization	$ 17
Amortization Period (in years)	1 year
Order backlog \| Minimum
Intangible Asset, Acquired, Finite-Lived [Line Items]
Amortization Period (in years)	1 year
Order backlog \| Maximum
Intangible Asset, Acquired, Finite-Lived [Line Items]
Amortization Period (in years)	3 years
Customer relationships
Intangible Asset, Acquired, Finite-Lived [Line Items]
Intangible assets subject to amortization	$ 37
Customer relationships \| Minimum
Intangible Asset, Acquired, Finite-Lived [Line Items]
Amortization Period (in years)	10 years
Customer relationships \| Maximum
Intangible Asset, Acquired, Finite-Lived [Line Items]
Amortization Period (in years)	20 years

SEGMENTS

12 Months Ended

Sep. 30, 2025

Segment Reporting [Abstract]

SEGMENTS

The Company’s businesses are organized and managed in three reporting segments: Power & Control, Airframe and Non-aviation.

The Power & Control segment includes operations that primarily develop, produce and market systems and components that predominately provide power to or control power of the aircraft utilizing electronic, fluid, power and mechanical motion control technologies. Major product offerings include mechanical/electromechanical actuators and controls, ignition systems and engine technology, specialized pumps and valves, power conditioning devices, specialized AC/DC electric motors and generators, batteries and chargers, databus and power controls, advanced sensor products, switches and relay panels, high performance hoists, winches and lifting devices, cargo loading, handling and delivery systems, electronic components used in the generation, amplification, transmission and reception of microwave signals, and single and two-stage servo values. Primary customers of this segment are engine and power system and subsystem suppliers, airlines, third party maintenance suppliers, military buying agencies and repair depots. Products are sold in the original equipment and aftermarket market channels.

The Airframe segment includes operations that primarily develop, produce and market systems and components that are used in non-power airframe applications utilizing airframe and cabin structure technologies. Major product offerings include engineered latching and locking devices, engineered rods, engineered connectors and elastomer sealing solutions, cockpit security components and systems, specialized and advanced cockpit displays, engineered audio, radio and antenna systems, specialized lavatory components, seat belts and safety restraints, engineered and customized interior surfaces and related components, thermal protection and insulation, lighting and control technology, parachutes, specialized flight, wind tunnel and jet engine testing services and equipment and complex testing and instrumentation solutions. Primary customers of this segment are airframe manufacturers and cabin system suppliers and subsystem suppliers, airlines, third party maintenance suppliers, military buying agencies and repair depots. Products are sold in the original equipment and aftermarket market channels.

The Non-aviation segment includes operations that primarily develop, produce and market products for non-aviation markets. Major product offerings include seat belts and safety restraints for ground transportation applications, mechanical/electromechanical actuators and controls for space applications, hydraulic/electromechanical actuators and fuel valves for land-based gas turbines, and refueling systems for heavy equipment used in mining, construction and other industries and turbine controls for the energy and oil and gas markets. Primary customers of this segment are off-road vehicle suppliers and subsystem suppliers, child restraint system suppliers, satellite and space system suppliers, manufacturers of heavy equipment used in mining, construction and other industries and turbine original equipment manufacturers, gas pipeline builders and electric utilities.

The Company’s segments are reported on the same basis used internally by our Chief Operating Decision Maker (“CODM”) for evaluating performance and for allocating resources. The Company’s CODM is collectively the President and Chief Executive Officer and Co-Chief Operating Officers. The primary measurement used internally by our CODM and management to review and assess the operating performance of each segment is EBITDA As Defined. Actual results are compared to plan, forecast and prior year on a monthly basis. The Company defines EBITDA As Defined as earnings before interest, taxes, depreciation and amortization plus certain non-operating items recorded as corporate expenses including non-cash compensation charges incurred in connection with the Company’s stock incentive or deferred compensation plans, foreign currency gains and losses, acquisition-integration costs, acquisition transaction-related expenses, and refinancing costs. Acquisition transaction and integration-related expenses represent costs incurred to integrate acquired businesses into TD Group’s operations; facility relocation costs and other acquisition-related costs; transaction and valuation-related costs for acquisitions comprising deal fees, legal, financial and tax due diligence expenses; amortization expense of inventory step-up recorded in connection with the purchase accounting of acquired businesses.

EBITDA As Defined is not a measurement of financial performance under U.S. GAAP. Although the Company uses EBITDA As Defined to assess the performance of its business and for various other purposes, the use of this non-GAAP financial measure as an analytical tool has limitations, and it should not be considered in isolation or as a substitute for analysis of the Company’s results of operations as reported in accordance with U.S. GAAP.

The accounting policies for each segment are the same as those described in the summary of significant accounting policies in Note 1 to the Company’s consolidated financial statements. Intersegment sales and transfers are recorded at values based on market prices, which creates intercompany profit on intersegment sales or transfers that is eliminated in consolidation. Intersegment sales were immaterial for the periods presented below. Corporate consists of our corporate offices. Corporate expenses consist primarily of compensation, benefits, professional services and other administrative costs incurred by the corporate offices. Corporate assets consist primarily of cash and cash equivalents. Corporate expenses and assets reconcile reportable segment data to the consolidated totals. An immaterial amount of corporate expenses is allocated to the operating segments.


	Fiscal Year Ended September 30, 2025
	Power & Control		Airframe		Non-aviation	Total
Net sales to external customers
Commercial and non-aerospace OEM	$	926	$	1,180		$	2,106
Commercial and non-aerospace aftermarket	1,360		1,444			2,804
Defense	2,273		1,488			3,761
Non-aviation	—		—		160	160
Net Sales	4,559		4,112		160	8,831
Less:
Other segment expenses (1)	1,964		1,902		93
Total segment EBITDA As Defined	2,595		2,210		67	4,872
Less: Unallocated corporate EBITDA As Defined						112
Depreciation and amortization expense						367
Interest expense-net						1,572
Acquisition transaction and integration-related expenses						42
Non-cash stock and deferred compensation expense						157
Refinancing costs						11
Other, net						(18)
Income from continuing operations before income taxes						$	2,629


	September 30, 2025
	Power & Control	Airframe	Non-aviation	Corporate (1)	Total
Total assets	9,859	10,267	202	2,581	22,909
Capital expenditures	108	103	9	2	222
Depreciation and amortization	180	181	6	—	367


	Fiscal Year Ended September 30, 2024
	Power & Control		Airframe		Non-aviation	Total
Net sales to external customers
Commercial and non-aerospace OEM	$	841	$	1,280		$	2,121
Commercial and non-aerospace aftermarket	1,218		1,290			2,508
Defense	1,907		1,239			3,146
Non-aviation	—		—		165	165
Net Sales	3,966		3,809		165	$	7,940
Less:
Other segment expenses (1)	1,715		1,847		99
Total segment EBITDA As Defined	2,251		1,962		66	4,279
Less: Unallocated corporate EBITDA As Defined						106
Depreciation and amortization expense						312
Interest expense-net						1,286
Acquisition transaction and integration-related expenses						70
Non-cash stock and deferred compensation expense						217
Refinancing costs						58
Other, net						15
Income from continuing operations before income taxes						$	2,215


	September 30, 2024
	Power & Control	Airframe	Non-aviation	Corporate (1)	Total
Total assets	9,180	10,045	193	6,168	25,586
Capital expenditures	90	73	2	—	165
Depreciation and amortization	133	172	6	1	312


	Fiscal Year Ended September 30, 2023
	Power & Control		Airframe		Non-aviation	Total
Net sales to external customers
Commercial and non-aerospace OEM	$	696	$	989		$	1,685
Commercial and non-aerospace aftermarket	1,074		1,112			2,186
Defense	1,569		993			2,562
Non-aviation	—		—		152	152
Net Sales	3,339		3,094		152	$	6,585
Less:
Other segment expenses (1)	1,459		1,547		95
Total segment EBITDA As Defined	1,880		1,547		57	3,484
Less: Unallocated corporate EBITDA As Defined						89
Depreciation and amortization expense						268
Interest expense-net						1,164
Acquisition transaction and integration-related expenses						18
Non-cash stock and deferred compensation expense						157
Refinancing costs						56
Other, net						16
Income from continuing operations before income taxes						$	1,716


	September 30, 2023
	Power & Control	Airframe	Non-aviation	Corporate (1)	Total
Total assets	7,356	8,972	193	3,449	19,970
Capital expenditures	67	65	6	1	139
Depreciation and amortization	110	152	5	1	268

Geographic Area Information

The following table presents net sales by geographic area (in millions):


	Fiscal Years Ended September 30,
	2025		2024		2023
Net sales
United States	$	5,535	$	5,032	$	4,265
Foreign Countries	3,296		2,908		2,320
	$	8,831	$	7,940	$	6,585

The following table presents long-lived assets by geographic area (in millions):


	September 30, 2025		September 30, 2024		September 30, 2023
Long-lived assets
United States	$	1,339	$	1,273	$	1,063
Foreign Countries	305		276		256
	$	1,644	$	1,549	$	1,319

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

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+ Details

DEBT (Tables)

12 Months Ended

Sep. 30, 2025

Debt Disclosure [Abstract]

Schedule of Debt

The Company’s debt consists of the following (in millions):


	September 30, 2025
	Gross Amount		Debt Issuance Costs		Original Issue Discount		Net Amount
Short-term borrowings—trade receivable securitization facility	$	725	$	(1)	$	—	$	724
Term loans	$	11,124	$	(43)	$	(33)	$	11,048
6.750% secured notes due 2028 (“2028 Secured Notes”)	2,100		(11)		(6)		2,083
4.625% senior subordinated notes due 2029 (“4.625% 2029 Notes”)	1,200		(5)		—		1,195
6.375% secured notes due 2029 (“2029 Secured Notes”)	2,750		(17)		(1)		2,732
4.875% senior subordinated notes due 2029 (“4.875% 2029 Notes”)	750		(3)		—		747
6.875% secured notes due 2030 (“2030 Secured Notes”)	1,450		(10)		—		1,440
7.125% secured notes due 2031 (“2031 Secured Notes”)	1,000		(8)		(6)		986
6.625% secured notes due 2032 (“2032 Secured Notes”)	2,200		(17)		—		2,183
6.000% secured notes due 2033 (“2033 Secured Notes”)	1,500		(12)		—		1,488
6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”)	2,650		(14)		(20)		2,616
6.250% secured notes due 2034 (“2034 Secured Notes”)	500		(5)		—		495
6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”)	2,000		(18)		—		1,982
Government refundable advances	12		—		—		12
Finance lease obligations	284		—		—		284
	29,520		(163)		(66)		29,291
Less: current portion	125		(1)		—		124
Long-term debt	$	29,395	$	(162)	$	(66)	$	29,167


	September 30, 2024
	Gross Amount		Debt Issuance Costs		Original Issue Discount		Net Amount
Short-term borrowings—trade receivable securitization facility	$	487	$	(1)	$	—	$	486
Term loans	$	8,702	$	(25)	$	(35)	$	8,642
5.500% senior subordinated notes due 2027 (“5.500% 2027 Notes”)	2,650		(9)		—		2,641
2028 Secured Notes	2,100		(15)		(8)		2,077
4.625% 2029 Notes	1,200		(6)		—		1,194
2029 Secured Notes	2,750		(22)		(1)		2,727
4.875% 2029 Notes	750		(4)		—		746
2030 Secured Notes	1,450		(12)		—		1,438
2031 Secured Notes	1,000		(9)		(7)		984
2032 Secured Notes	2,200		(20)		—		2,180
2033 Secured Notes	1,500		(14)		—		1,486
Government refundable advances	17		—		—		17
Finance lease obligations	262		—		—		262
	24,581		(136)		(51)		24,394
Less: current portion	99		(1)		—		98
Long-term debt	$	24,482	$	(135)	$	(51)	$	24,296

Schedule of Term Loans


Term Loans Facility	Maturity Date	Interest Rate under Term Loans Facility	Aggregate Principal as of September 30,
			2025		2024
Tranche I (1)	August 24, 2028	Term SOFR plus 2.75%	$	—	$	1,871
Tranche J	February 28, 2031	Term SOFR plus 2.50%	$	3,595	$	3,632
Tranche K	March 22, 2030	Term SOFR plus 2.25%	$	3,544	$	1,699
Tranche L	January 19, 2032	Term SOFR plus 2.50%	$	1,485	$	1,500
Tranche M	August 19, 2032	Term SOFR plus 2.50%	$	2,500	$	—

(1)As previously disclosed within this note, during fiscal 2025, Tranche I was converted into Tranche K.

Future Maturities of Long-Term Debt

At September 30, 2025, future maturities of long-term debt (excluding finance leases) are as follows (in millions), refer to Note 17, “Leases,” for future maturities of finance leases:


Fiscal Years Ended September 30,
2026	$	116
2027	116
2028	2,216
2029	4,812
2030	3,478
Thereafter	18,498
Total	$	29,236

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

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-Section S99
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+ Details

STOCK REPURCHASE PROGRAM - Narratives (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Nov. 30, 2025	Nov. 08, 2017
Shareholders Equity [Line Items]
Common stock, authorized (in shares)		224,400,000	224,400,000
Common stock, par or stated value (in usd per share)		$ 0.01	$ 0.01
Preferred stock, shares authorized		149,600,000
Preferred stock, par value		$ 0.01
Common stock, issued (in shares)		62,465,317	61,904,833
Treasury stock, common (in shares)		6,089,675	5,688,639
Preferred stock, shares outstanding		0	0
Stock Repurchase Program, Authorized Amount		$ 2,200				$ 650
Treasury Stock Acquired, Average Cost Per Share		$ 1,246.71
Payments for Repurchase of Common Stock		$ 500	$ 0	$ 0
Shares repurchased under the program		401,036
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 788
Subsequent Event
Shareholders Equity [Line Items]
Stock Repurchase Program, Authorized Amount					$ 5,000
Treasury Stock Acquired, Average Cost Per Share	$ 1,249.9
Payments for Repurchase of Common Stock	$ 100
Shares repurchased under the program	79,959

EARNINGS PER SHARE

12 Months Ended

Sep. 30, 2025

Earnings Per Share [Abstract]

EARNINGS PER SHARE

The following table sets forth the computation of basic and diluted earnings per share (in millions, except per share data) using the two-class method:


	Fiscal Years Ended September 30,
	2025		2024		2023
Numerator for earnings per share:
Net income	$	2,074	$	1,715	$	1,299
Less: Net income attributable to noncontrolling interests	—		(1)		(1)
Net income attributable to TD Group	2,074		1,714		1,298
Less: Dividends declared or paid on participating securities	(208)		(233)		(38)

Net income applicable to TD Group common stockholders—basic and diluted	$	1,866	$	1,481	$	1,260
Denominator for basic and diluted earnings per share under the two-class method:
Weighted-average common shares outstanding	56.3		55.8		54.9
Vested options deemed participating securities	1.9		2.0		2.3
Total shares for basic and diluted earnings per share	58.2		57.8		57.2



Earnings per share—basic and diluted (1)	$	32.08	$	25.62	$	22.03

(1)Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated using unrounded numbers.

ACCRUED AND OTHER CURRENT LIABILITIES (Tables)

12 Months Ended

Sep. 30, 2025

Payables and Accruals [Abstract]

ACCRUED AND OTHER CURRENT LIABILITIES

Accrued and other current liabilities consist of the following (in millions):


	September 30, 2025		September 30, 2024
Compensation and related benefits	$	235	$	256
Interest	208		185
Contract liabilities, current (Note 3)	143		168
Dividend equivalent payments, current (Note 16)	59		180
Income taxes payable, current	40		108
Product warranties	37		36
Environmental and other litigation reserves	25		27
Current operating lease liabilities (Note 17)	15		19
Foreign currency forward exchange contracts (Note 18)	2		1
Other	202		236
Accrued and other current liabilities	$	966	$	1,216

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narratives (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Summary Of Significant Accounting Policies [Line Items]
Research and development expense	$ 118.0	$ 107.0	$ 105.0
Business acquisition cost	$ 6.0	$ 33.0	$ 6.0
Land Improvements \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	10 years
Land Improvements \| Maximum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	20 years
Building and improvements \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	5 years
Building and improvements \| Maximum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	30 years
Machinery and equipment \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	2 years
Machinery and equipment \| Maximum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	10 years
Furniture and Fixtures \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	3 years
Furniture and Fixtures \| Maximum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	10 years
Technology Intangible Assets \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Finite lived intangible asset useful life	10 years
Technology Intangible Assets \| Maximum
Summary Of Significant Accounting Policies [Line Items]
Finite lived intangible asset useful life	22 years
Order backlog
Summary Of Significant Accounting Policies [Line Items]
Finite lived intangible asset useful life	1 year
Order backlog \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Finite lived intangible asset useful life	1 year
Order backlog \| Maximum
Summary Of Significant Accounting Policies [Line Items]
Finite lived intangible asset useful life	3 years
Customer Relationships \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Finite lived intangible asset useful life	10 years
Other Intangible Assets \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Finite lived intangible asset useful life	20 years

DEBT - Redemption of $2,650 million of Senior Subordinated Notes due 2027 (Details) - USD ($) $ in Millions			12 Months Ended
	Jun. 20, 2025	May 20, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
REFINANCING COSTS			$ 11	$ 58	$ 56
5.500% senior subordinated notes due 2027 (“5.500% 2027 Notes”) \| Senior Subordinated Notes
Debt Instrument [Line Items]
Debt Instrument, repurchased face amount	$ 2,650
Interest rate			5.50%
Debt instrument, redemption price, percentage	100.00%
REFINANCING COSTS			$ 7
6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”) \| Senior Subordinated Notes
Debt Instrument [Line Items]
Interest rate		6.375%	6.375%
Debt instrument, redemption price, percentage		99.225%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

DEBT - Senior Secured Term Loans Facility (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024	Feb. 27, 2024
Debt Instrument [Line Items]
Gross Amount	$ 29,520	$ 24,581
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	910	$ 910
Line of Credit Facility, Remaining Borrowing Capacity	$ 857
Interest rate		2.25%	2.25%
Debt Instrument, Unused Portion, Fee, Percent	0.50%	0.50%
Term loans
Debt Instrument [Line Items]
Gross Amount	$ 11,124	$ 8,702
Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity		$ 843

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

GOODWILL AND INTANGIBLE ASSETS (Tables)

12 Months Ended

Sep. 30, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Changes in Carrying Value of Goodwill

The following is a summary of changes in the carrying value of goodwill by segment for the fiscal years ended September 30, 2024 and 2025 (in millions):


	Power & Control		Airframe		Non-aviation		Total
Balance at September 30, 2023	$	4,208	$	4,701	$	79	$	8,988
Goodwill acquired during the period	786		563		—		1,349
Purchase price allocation adjustments (1)	—		35		—		35
Currency translation adjustments and other	40		7		—		47
Balance at September 30, 2024	5,034		5,306		79		10,419
Goodwill acquired during the period	189		13		—		202
Purchase price allocation adjustments (2)	18		(56)		—		(38)
Currency translation adjustments and other	32		(3)		—		29
Balance at September 30, 2025	$	5,273	$	5,260	$	79	$	10,612

(1)Primarily related to the opening balance sheet adjustments recorded from the fiscal 2023 acquisition of Calspan Corporation within the allowable measurement period (not to exceed one year).

Schedule of Intangible Assets

Other intangible assets–net in the consolidated balance sheets consist of the following at September 30 (in millions):


	2025						2024
	Gross Carrying Amount		Accumulated Amortization		Net		Gross Carrying Amount		Accumulated Amortization		Net
Trademarks and trade names	$	1,162	$	—	$	1,162	$	1,165	$	—	$	1,165
Technology	2,647		1,137		1,510		2,510		1,003		1,507
Order backlog	59		28		31		61		13		48
Customer relationships	971		225		746		895		175		720
Other	12		7		5		12		6		6
Total	$	4,851	$	1,397	$	3,454	$	4,643	$	1,197	$	3,446

Schedule of Acquired Indefinite-lived Intangible Assets by Major Class

Intangible assets acquired during the fiscal year ended September 30, 2025 are summarized in the table below (in millions):


	Gross Amount		Amortization Period
Intangible assets not subject to amortization:
Trademarks and trade names	$	11

Intangible assets subject to amortization:
Technology & Other	71		10 to 20 years
Order backlog	17		1 year
Customer relationships	37		10 to 20 years
	125

Total	$	136

Schedule of Aggregate Amortization Expense

Information regarding the amortization expense of amortizable intangible assets is detailed below (in millions):

Annual Amortization Expense:


Fiscal Years Ended September 30,
2025	$	201
2024	161
2023	139

Schedule of Finite-Lived Intangible Assets, Future Amortization

Estimated Amortization Expense:


Fiscal Years Ended September 30,
2026	$	203
2027	187
2028	179
2029	178
2030	170

- Definition

Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.

+ References

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+ Details

STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

Weighted Average Assumptions for all Options Granted Estimated at Grant Date Using Black-Scholes-Merton Option-Pricing Model


	Fiscal Years Ended September 30,
	2025	2024	2023
Risk-free interest rate	4.0% to 4.5%	4.1% to 4.7%	3.5% to 4.2%
Expected life of options	6.5 years	6.5 years	6.5 years
Expected dividend yield of stock	—	—	—
Expected volatility of stock	32.5%	33.5%	32.5%

Summary of Activity, Pricing and Other Information for Performance Vested Stock-Based Award Activity

The following table summarizes the activity, pricing and other information for the Company’s performance vested stock-based award activity during the fiscal year ended September 30, 2025:


	Number of Options	Weighted-Average Exercise Price Per Option		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding at September 30, 2024	561,109	$	795.95
Granted	346,664	1,316.43
Exercised	(26,420)	656.47
Forfeited	(121,745)	909.08
Expired	—	—
Outstanding at September 30, 2025	759,608	$	1,020.20	8.4 years	$	226,226,455
Expected to vest	409,971	$	1,051.67	8.5 years	$	109,195,776
Exercisable at September 30, 2025	93,696	$	724.47	7.6 years	$	55,613,261

The following table summarizes the activity, pricing and other information for the Company’s performance vested stock-based award activity during the fiscal year ended September 30, 2025:


	Number of Options	Weighted-Average Exercise Price Per Option		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding at September 30, 2024	3,779,503	$	466.18
Granted	—	—
Exercised	(462,368)	288.80
Forfeited	(86,209)	620.43
Expired	—	—
Outstanding at September 30, 2025	3,230,926	$	487.45	4.4 years	$	2,683,510,208
Expected to vest	478,730	$	670.73	7.1 years	$	309,877,142
Exercisable at September 30, 2025	2,429,832	$	376.64	3.6 years	$	2,287,395,248

STOCK-BASED COMPENSATION - Weighted Average Assumptions used to Estimate Fair Value of all Options at Grant Date using Black-Scholes-Merton Option-Pricing Model (Detail)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Risk-free interest rate, minimum	4.00%	4.10%	3.50%
Risk-free interest rate, maximum	4.50%	4.70%	4.20%
Expected life of options	6 years 6 months	6 years 6 months	6 years 6 months
Expected dividend yield of stock	0.00%	0.00%	0.00%
Expected volatility of stock	32.50%	33.50%	32.50%

REVENUE RECOGNITION (Details) - USD ($) $ in Millions	12 Months Ended
REVENUE RECOGNITION (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Revenues	$ 8,831	$ 7,940	$ 6,585
Contract with Customer, Asset, Net, Current	280	270
Contract with Customer, Asset, Net, Noncurrent	94	31
Contract with Customer, Asset, after Allowance for Credit Loss	374	301
Contract liabilities, current (Note 3)	143	168
Contract with Customer, Liability, Noncurrent	7	9
Contract with Customer, Liability	150	177
Net Contract Asset	224	$ 124
Contract With Customer Liability, Revenue Recognized, Excluding Opening Balance	$ 125
Revenue Benchmark [Member] \| Customer Concentration Risk \| Customer 1
Percentage of net sales from one customer	10.00%	10.00%	10.00%
Geographic Distribution, Foreign
Revenues	$ 3,296	$ 2,908	$ 2,320

SEGMENTS - Narratives (Detail)	12 Months Ended
SEGMENTS - Narratives (Detail)	Sep. 30, 2025 Segment
Segment Reporting [Abstract]
Number of reporting segments	3

GOODWILL AND INTANGIBLE ASSETS - Schedule of Aggregate Amortization Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 201	$ 161	$ 139

- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)

12 Months Ended

Sep. 30, 2025

Equity [Abstract]

Schedule of Accumulated Other Comprehensive Loss

The following table presents the total changes by component in accumulated other comprehensive loss (“AOCL”), net of taxes, for the fiscal years ended September 30, 2025 and 2024 (in millions):


	Unrealized losses on derivatives (1)		Pension and post-retirement benefit plans adjustment (2)		Foreign currency translation adjustment (3)		Total
Balance at September 30, 2023	$	143	$	2	$	(243)	$	(98)


Net current-period other comprehensive (loss) income (4)	(124)		(1)		181		56
Balance at September 30, 2024	19		1		(62)		(42)


Net current-period other comprehensive (loss) income (4)	(23)		(3)		58		32
Balance at September 30, 2025	$	(4)	$	(2)	$	(4)	$	(10)

LEASES - Operating and Finance Leases, Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 65	$ 61
Current operating lease liabilities (Note 17)	15	19
Operating Lease, Liability, Noncurrent	51	43
Operating Lease, Liability	66	62
Finance Lease, Right-of-Use Asset	264	252
Finance Lease, Liability, Current	8	6
Finance Lease, Liability, Noncurrent	276	256
Finance lease obligations	$ 284	$ 262
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	OTHER NON-CURRENT ASSETS	OTHER NON-CURRENT ASSETS
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued and other current liabilities	Accrued and other current liabilities
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	OTHER NON-CURRENT LIABILITIES	OTHER NON-CURRENT LIABILITIES
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	PROPERTY, PLANT AND EQUIPMENT—NET	PROPERTY, PLANT AND EQUIPMENT—NET
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Current portion of long-term debt	Current portion of long-term debt
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	LONG-TERM DEBT	LONG-TERM DEBT

FAIR VALUE MEASUREMENTS

12 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

The following table presents our assets and liabilities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy. The fair value hierarchy has three levels based on the reliability of the inputs used to determine fair value. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities. Level 2 inputs are quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and inputs (other than quoted prices) that are observable for the asset or liability, either directly or indirectly. Level 3 inputs are unobservable inputs for the asset or liability. A financial asset or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement.

The following summarizes the carrying amounts and fair values of financial instruments (in millions):


		September 30, 2025				September 30, 2024
	Level	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Assets:
Cash and cash equivalents	1	$	2,808	$	2,808	$	6,261	$	6,261
Interest rate swap agreements (1)	2	3		3		34		34
Interest rate cap agreements (1)	2	—		—		20		20
Interest rate collar agreements (1)	2	4		4		—		—
Foreign currency forward exchange contracts (1)	2	—		—		3		3
Interest rate swap agreements (2)	2	5		5		—		—

Interest rate collar agreements (2)	2	3		3		3		3
Liabilities:
Interest rate swap agreements (3)	2	—		—		1		1
Interest rate cap agreements (3)	2	—		—		1		1
Foreign currency forward exchange contracts (3)	2	2		2		—		—


Interest rate collar agreements (4)	2	3		3		8		8
Short-term borrowings - trade receivable securitization facility (5)	2	724		724		486		486
Long-term debt, including current portion:
Term loans (5)	2	11,048		11,120		8,642		8,694
5.500% 2027 Notes (5)	1	—		—		2,641		2,637
2028 Secured Notes (5)	1	2,083		2,139		2,077		2,160
4.625% 2029 Notes (5)	1	1,195		1,175		1,194		1,160
2029 Secured Notes (5)	1	2,732		2,812		2,727		2,836
4.875% 2029 Notes (5)	1	747		739		746		729
2030 Secured Notes (5)	1	1,440		1,501		1,438		1,519
2031 Secured Notes (5)	1	986		1,041		984		1,058
2032 Secured Notes (5)	1	2,183		2,263		2,180		2,291
2033 Secured Notes (5)	1	1,488		1,517		1,486		1,521
6.375% 2033 Notes (5)	1	2,616		2,686		—		—
2034 Secured Notes (5)	1	495		514		—		—
6.750% 2034 Notes (5)	1	1,982		2,068		—		—
Government refundable advances	2	12		12		17		17
Finance lease obligations	2	284		284		262		262

(1)Included in prepaid expenses and other on the consolidated balance sheets.

(2)Included in other assets on the consolidated balance sheets.

(3)Included in accrued and other current liabilities on the consolidated balance sheets.

(4)Included in other non-current liabilities on the consolidated balance sheets.

(5)The carrying amount of the debt instrument is presented net of debt issuance costs and original issue discount. Refer to Note 10, “Debt,” for gross carrying amounts.

The Company values its financial instruments using an industry standard market approach, in which prices and other relevant information are generated by market transactions involving identical or comparable assets or liabilities. No financial instruments were recognized or disclosed using unobservable inputs (i.e., Level 3).

The Company’s derivatives consist of interest rate swap, cap and collar agreements and foreign currency exchange contracts. The fair values of the interest rate swap, cap and collar agreements were derived by taking the net present value of the expected cash flows using observable market inputs (Level 2) such as SOFR rate curves, futures, volatilities and basis spreads (when applicable). The fair values of the foreign currency exchange contracts were derived by using Level 2 inputs based on observable spot and forward exchange rates in active markets. There has not been any impact to the fair value of derivative liabilities due to the Company's own credit risk. Similarly, there has not been any material impact to the fair value of derivative assets based on the Company's evaluation of counterparties' credit risks.

The estimated fair value of the Company’s term loans was based on information provided by the agent under the Company’s Credit Agreement. The estimated fair values of the Company’s notes were based upon quoted market prices.

The fair value of cash and cash equivalents, trade accounts receivable-net and accounts payable approximated carrying value due to the short-term nature of these instruments at September 30, 2025 and 2024.

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
NET SALES	$ 8,831	$ 7,940	$ 6,585
COST OF SALES	3,520	3,268	2,743
GROSS PROFIT	5,311	4,672	3,842
SELLING AND ADMINISTRATIVE EXPENSES	945	980	780
AMORTIZATION OF INTANGIBLE ASSETS	201	161	139
INCOME FROM OPERATIONS	4,165	3,531	2,923
INTEREST EXPENSE—NET	1,572	1,286	1,164
REFINANCING COSTS	11	58	56
OTHER INCOME	(47)	(28)	(13)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	2,629	2,215	1,716
INCOME TAX PROVISION	555	500	417
Net income	2,074	1,715	1,299
LESS: NET INCOME ATTRIBUTABLE TO NONCONTROLLING INTERESTS	0	(1)	(1)
NET INCOME ATTRIBUTABLE TO TD GROUP	2,074	1,714	1,298
NET INCOME APPLICABLE TO TD GROUP COMMON STOCKHOLDERS	$ 1,866	$ 1,481	$ 1,260
Earnings Per Share [Abstract]
Earnings per share from continuing operations - basic (in usd per share)	$ 32.08	$ 25.62	$ 22.03
Earnings per share from continuing operations - diluted (in usd per share)	32.08	25.62	22.03
Cash dividends declared per common share (in usd per share)	$ 90.00	$ 110.00	$ 0
Weighted-average shares outstanding:
Weighted-average shares outstanding - basic (in shares)	58.2	57.8	57.2
Weighted-average shares outstanding - diluted (in shares)	58.2	57.8	57.2

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
Cybersecurity Risk Management and Strategy Disclosure	Sep. 30, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	We have established a risk-based cybersecurity and information security program (“program”) designed to assess, identify, and manage material risks from cybersecurity threats. Our cybersecurity risk management process includes policies that specify the requirements for technical security controls, monitoring systems, tools and services from third-party providers, and employee training and awareness. Our cybersecurity risk management process also includes regular independent audits across our operating units. Management oversees our cybersecurity risk management process in order to assess and manage material risks from cybersecurity threats identified by both internal and external threat intelligence. Our program monitors and evaluates risks from cybersecurity threats, and we aim to adapt our program and related processes accordingly. The multi-layered framework on which our cybersecurity and information security program is built incorporates cybersecurity standards and certain requirements of the National Institute of Standards and Technology (“NIST”) Special Publication 800-171—Protecting Controlled Unclassified Information in Non-Federal Systems and Organizations—along with other legal and regulatory requirements. However, this does not mean that we meet any particular technical standards, specifications, or requirements, but rather that we use NIST and other cybersecurity standards as a guide to help us identify, assess, and manage cybersecurity risks relevant to our business. Our cybersecurity and information security program is led by the Company’s Vice President of Cybersecurity (“VPoC”) who reports to our Chief Financial Officer. Our VPoC has served as a technology leader of cybersecurity, information security, infrastructure, and operational functions for over 35 years. The VPoC is supported by the Incident Response Team (“IRT”), a management committee made up of the Co-Chief Operating Officers, Chief Financial Officer, and executives in legal, finance, IT, and audit. The IRT supports the VPoC in assessing and managing risks from cybersecurity threats and in the event of a cybersecurity incident, provides oversight and leadership with respect to incident response. As adopted by our businesses, which has been overseen by our corporate executive team, we have a cybersecurity incident response plan that outlines our policies and procedures to identify, respond to, and recover from cybersecurity threats and cybersecurity incidents. Our businesses are required to conduct regular exercises of their incident response plan as part of our program. In the event of a potentially material cybersecurity incident, as determined by the VPoC with support from legal, as needed, the IRT is notified through an established escalation protocol. The Chair of the Audit Committee is also notified and briefed, and meetings of the Audit Committee and/or full Board of Directors would be held as appropriate. We maintain a relationship with third-party forensic vendor(s) available for incident response and investigation. Additionally, we maintain cybersecurity insurance. The Company’s Board of Directors oversees our enterprise risk management (“ERM”) program and has delegated the primary responsibility for its oversight, which includes oversight of cybersecurity risk, to the Audit Committee. The Audit Committee is informed of material risks from cybersecurity threats through regular discussion with management regarding cybersecurity risk mitigation and cybersecurity incident management. Executive management, including our VPoC, regularly presents to the Audit Committee regarding cybersecurity matters, including program updates, key metrics, and developments. The ERM program inventories and classifies key risk areas. We employ a methodology for scoring the risks based on the probability and impact of individual risks and discuss and implement countermeasures to address the risks.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	The multi-layered framework on which our cybersecurity and information security program is built incorporates cybersecurity standards and certain requirements of the National Institute of Standards and Technology (“NIST”) Special Publication 800-171—Protecting Controlled Unclassified Information in Non-Federal Systems and Organizations—along with other legal and regulatory requirements. However, this does not mean that we meet any particular technical standards, specifications, or requirements, but rather that we use NIST and other cybersecurity standards as a guide to help us identify, assess, and manage cybersecurity risks relevant to our business.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	Our cybersecurity and information security program is led by the Company’s Vice President of Cybersecurity (“VPoC”) who reports to our Chief Financial Officer. Our VPoC has served as a technology leader of cybersecurity, information security, infrastructure, and operational functions for over 35 years. The VPoC is supported by the Incident Response Team (“IRT”), a management committee made up of the Co-Chief Operating Officers, Chief Financial Officer, and executives in legal, finance, IT, and audit. The IRT supports the VPoC in assessing and managing risks from cybersecurity threats and in the event of a cybersecurity incident, provides oversight and leadership with respect to incident response. As adopted by our businesses, which has been overseen by our corporate executive team, we have a cybersecurity incident response plan that outlines our policies and procedures to identify, respond to, and recover from cybersecurity threats and cybersecurity incidents. Our businesses are required to conduct regular exercises of their incident response plan as part of our program. In the event of a potentially material cybersecurity incident, as determined by the VPoC with support from legal, as needed, the IRT is notified through an established escalation protocol. The Chair of the Audit Committee is also notified and briefed, and meetings of the Audit Committee and/or full Board of Directors would be held as appropriate. We maintain a relationship with third-party forensic vendor(s) available for incident response and investigation. Additionally, we maintain cybersecurity insurance. The Company’s Board of Directors oversees our enterprise risk management (“ERM”) program and has delegated the primary responsibility for its oversight, which includes oversight of cybersecurity risk, to the Audit Committee. The Audit Committee is informed of material risks from cybersecurity threats through regular discussion with management regarding cybersecurity risk mitigation and cybersecurity incident management. Executive management, including our VPoC, regularly presents to the Audit Committee regarding cybersecurity matters, including program updates, key metrics, and developments. The ERM program inventories and classifies key risk areas. We employ a methodology for scoring the risks based on the probability and impact of individual risks and discuss and implement countermeasures to address the risks.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	As adopted by our businesses, which has been overseen by our corporate executive team, we have a cybersecurity incident response plan that outlines our policies and procedures to identify, respond to, and recover from cybersecurity threats and cybersecurity incidents. Our businesses are required to conduct regular exercises of their incident response plan as part of our program.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	In the event of a potentially material cybersecurity incident, as determined by the VPoC with support from legal, as needed, the IRT is notified through an established escalation protocol. The Chair of the Audit Committee is also notified and briefed, and meetings of the Audit Committee and/or full Board of Directors would be held as appropriate. We maintain a relationship with third-party forensic vendor(s) available for incident response and investigation. Additionally, we maintain cybersecurity insurance.
Cybersecurity Risk Role of Management [Text Block]	The Company’s Board of Directors oversees our enterprise risk management (“ERM”) program and has delegated the primary responsibility for its oversight, which includes oversight of cybersecurity risk, to the Audit Committee. The Audit Committee is informed of material risks from cybersecurity threats through regular discussion with management regarding cybersecurity risk mitigation and cybersecurity incident management. Executive management, including our VPoC, regularly presents to the Audit Committee regarding cybersecurity matters, including program updates, key metrics, and developments.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	Our cybersecurity and information security program is led by the Company’s Vice President of Cybersecurity (“VPoC”) who reports to our Chief Financial Officer. Our VPoC has served as a technology leader of cybersecurity, information security, infrastructure, and operational functions for over 35 years. The VPoC is supported by the Incident Response Team (“IRT”), a management committee made up of the Co-Chief Operating Officers, Chief Financial Officer, and executives in legal, finance, IT, and audit. The IRT supports the VPoC in assessing and managing risks from cybersecurity threats and in the event of a cybersecurity incident, provides oversight and leadership with respect to incident response.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Our VPoC has served as a technology leader of cybersecurity, information security, infrastructure, and operational functions for over 35 years.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	In the event of a potentially material cybersecurity incident, as determined by the VPoC with support from legal, as needed, the IRT is notified through an established escalation protocol. The Chair of the Audit Committee is also notified and briefed, and meetings of the Audit Committee and/or full Board of Directors would be held as appropriate. We maintain a relationship with third-party forensic vendor(s) available for incident response and investigation. Additionally, we maintain cybersecurity insurance.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' DEFICIT - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interests
Beginning balance (in shares) at Sep. 30, 2023		60,995,513
Treasury stock, beginning balance (in shares) at Sep. 30, 2022						(5,688,639)
Beginning balance at Sep. 30, 2022	$ (3,766)	$ 1	$ 2,113	$ (3,914)	$ (267)	$ (1,706)	$ 7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Changes in noncontrolling interest of consolidated subsidiaries, net	(1)						(1)
Accrued unvested dividend equivalents and other	(5)			(5)
Compensation expense recognized for employee stock options	112		112
Stock-based compensation activity (in shares)		945,828
Stock-based compensation activity	215		215
Net income attributable to TD Group	1,298			1,298
Foreign currency translation adjustment, net of tax	137				137
Unrealized loss on derivatives, net of tax	20				20
Pension and post-retirement benefit plans adjustment, net of tax	12				12
Ending balance (in shares) at Sep. 30, 2022		60,049,685
Treasury stock, ending balance (in shares) at Sep. 30, 2023						(5,688,639)
Ending balance at Sep. 30, 2023	$ (1,978)	$ 1	2,440	(2,621)	(98)	$ (1,706)	6
Beginning balance (in shares) at Sep. 30, 2024	61,904,833	61,904,833
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Changes in noncontrolling interest of consolidated subsidiaries, net	$ 1						1
Special dividends and vested dividend equivalents declared	(6,368)			(6,368)
Accrued unvested dividend equivalents and other	(87)			(87)
Compensation expense recognized for employee stock options	134		134
Stock-based compensation activity (in shares)		909,320
Stock-based compensation activity	245		245
Net income attributable to TD Group	1,714			1,714
Foreign currency translation adjustment, net of tax	181				181
Unrealized loss on derivatives, net of tax	(124)				(124)
Pension and post-retirement benefit plans adjustment, net of tax	$ (1)				(1)
Ending balance (in shares) at Sep. 30, 2023		60,995,513
Treasury stock, ending balance (in shares) at Sep. 30, 2024	(5,688,639)					(5,688,639)
Ending balance at Sep. 30, 2024	$ (6,283)	$ 1	2,819	(7,362)	(42)	$ (1,706)	7
Beginning balance (in shares) at Sep. 30, 2025	62,465,317	62,465,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Special dividends and vested dividend equivalents declared	$ (5,232)			(5,232)
Accrued unvested dividend equivalents and other	(86)			(86)
Compensation expense recognized for employee stock options	150		150
Stock-based compensation activity (in shares)		560,484
Stock-based compensation activity	$ 166		166
Stock repurchases under repurchase program (in shares)	(401,036)					(401,036)
Stock repurchases under repurchase program	$ (500)					$ (500)
Net income attributable to TD Group	2,074			2,074
Foreign currency translation adjustment, net of tax	58				58
Unrealized loss on derivatives, net of tax	(23)				(23)
Pension and post-retirement benefit plans adjustment, net of tax	$ (3)				(3)
Ending balance (in shares) at Sep. 30, 2024	61,904,833	61,904,833
Treasury stock, ending balance (in shares) at Sep. 30, 2025	(6,089,675)					(6,089,675)
Ending balance at Sep. 30, 2025	$ (9,679)	$ 1	$ 3,135	$ (10,606)	$ (10)	$ (2,206)	$ 7

ACCRUED AND OTHER CURRENT LIABILITIES

12 Months Ended

Sep. 30, 2025

Payables and Accruals [Abstract]

ACCRUED AND OTHER CURRENT LIABILITIES

Accrued and other current liabilities consist of the following (in millions):


	September 30, 2025		September 30, 2024
Compensation and related benefits	$	235	$	256
Interest	208		185
Contract liabilities, current (Note 3)	143		168
Dividend equivalent payments, current (Note 16)	59		180
Income taxes payable, current	40		108
Product warranties	37		36
Environmental and other litigation reserves	25		27
Current operating lease liabilities (Note 17)	15		19
Foreign currency forward exchange contracts (Note 18)	2		1
Other	202		236
Accrued and other current liabilities	$	966	$	1,216

DEBT - Amendment No. 19 Loan Modification Agreement and Refinancing Facility Agreement (Details) - USD ($) $ in Millions				12 Months Ended
	Dec. 31, 2025	Sep. 17, 2025	Sep. 16, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Debt instrument, face amount				$ 29,236
REFINANCING COSTS				$ 11	$ 58	$ 56
Tranche K \| Term loans
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,686
Debt Instrument, Basis Spread on Variable Rate		2.25%	2.75%	2.25%
REFINANCING COSTS				$ 3
Tranche K \| Term loans \| Forecast
Debt Instrument [Line Items]
Debt instrument, quarterly principal payment	$ 9
Tranche I \| Term loans
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,857
Debt Instrument, Basis Spread on Variable Rate				2.75%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

FAIR VALUE MEASUREMENTS Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Assets, Carrying Amount	$ 2,808	$ 6,261
Short-term borrowings - trade receivable securitization facility, Carrying Amount	724	486
Net Amount	29,291	24,394
Prepaid Expenses and Other
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Cap Assets	0	20
Interest Rate Collar Assets	4	0
Foreign Currency Contract, Asset	0	3
Interest Rate Swap Asset Carrying Amount	3	34
Other Noncurrent Assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Collar Assets	3	3
Interest Rate Swap Asset Carrying Amount	5	0
Accrued Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Cap Liabilities	0	1
Interest rate swap agreements, Liabilities, Carrying Amount	0	1
Foreign Currency Contract, Liability	2	0
Other Non-Current Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Collar Liability	3	8
Term loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	11,048	8,642
Government Refundable Advances
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	12	17
Finance lease obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	284	262
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Assets, Fair Value	2,808	6,261
Fair Value, Inputs, Level 2 [Member] \| Prepaid Expenses and Other
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Cap Assets	0	20
Interest Rate Collar Assets	4	0
Foreign Currency Contract, Asset	0	3
Interest Rate Swap Asset at Fair Value	3	34
Fair Value, Inputs, Level 2 [Member] \| Other Noncurrent Assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Collar Assets	3	3
Interest Rate Swap Asset at Fair Value	5	0
Fair Value, Inputs, Level 2 [Member] \| Accrued Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Cap Liabilities	0	1
Interest Rate Cash Flow Hedge Liability at Fair Value	0	1
Foreign Currency Contract, Liability	2	0
Fair Value, Inputs, Level 2 [Member] \| Other Non-Current Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Collar Liability	3	8
Fair Value, Inputs, Level 2 [Member] \| Term loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	11,120	8,694
Fair Value, Inputs, Level 2 [Member] \| Government Refundable Advances
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	12	17
Fair Value, Inputs, Level 2 [Member] \| Finance lease obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	284	262
6.750% secured notes due 2028 (“2028 Secured Notes”) \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	2,083	2,077
6.750% secured notes due 2028 (“2028 Secured Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	2,139	2,160
5.500% senior subordinated notes due 2027 (“5.500% 2027 Notes”) \| Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	0	2,641
5.500% senior subordinated notes due 2027 (“5.500% 2027 Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	0	2,637
4.625% senior subordinated notes due 2029 (“4.625% 2029 Notes”) \| Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	1,195	1,194
4.625% senior subordinated notes due 2029 (“4.625% 2029 Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	1,175	1,160
4.875% senior subordinated notes due 2029 (“4.875% 2029 Notes”) \| Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	747	746
4.875% senior subordinated notes due 2029 (“4.875% 2029 Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	739	729
6.875% secured notes due 2030 (“2030 Secured Notes”) \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	1,440	1,438
6.875% secured notes due 2030 (“2030 Secured Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	1,501	1,519
6.375% secured notes due 2029 (“2029 Secured Notes”) \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	2,732	2,727
6.375% secured notes due 2029 (“2029 Secured Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	2,812	2,836
7.125% secured notes due 2031 (“2031 Secured Notes”) \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	986	984
7.125% secured notes due 2031 (“2031 Secured Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	1,041	1,058
6.625% secured notes due 2032 (“2032 Secured Notes”) \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	2,183	2,180
6.625% secured notes due 2032 (“2032 Secured Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	2,263	2,291
6.000% secured notes due 2033 (“2033 Secured Notes”) \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	1,488	1,486
6.000% secured notes due 2033 (“2033 Secured Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	1,517	1,521
6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”) \| Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	2,616
6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”) \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	2,616	0
6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	2,686	0
6.250% secured notes due 2034 (“2034 Secured Notes”) \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	495	0
6.250% secured notes due 2034 (“2034 Secured Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	514	0
6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”) \| Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	1,982
6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”) \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net Amount	1,982	0
6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”) \| Fair Value, Inputs, Level 1 [Member] \| Secured Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, Fair Value	2,068	0
Asset-backed Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings - trade receivable securitization facility, Carrying Amount	724	486
Asset-backed Securities \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings - trade receivable securitization facility, Fair Value	$ 724	$ 486

DEBT - Amendment No. 18 and Incremental Term Loan Assumption Agreement (Details) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
	Dec. 31, 2025	Aug. 19, 2025	Sep. 30, 2025
Debt Instrument [Line Items]
Debt instrument, face amount			$ 29,236
S 2025 Dividends
Debt Instrument [Line Items]
Dividends declared (in dollars per share)			$ 90.00
Tranche M \| Term loans
Debt Instrument [Line Items]
Debt instrument, face amount		$ 2,500
Original Issue Discount Rate		0.25%
Debt instrument, unamortized discount		$ 6
Debt Instrument, Basis Spread on Variable Rate		2.50%	2.50%
Debt issuance costs		$ 23
Tranche M \| Term loans \| Forecast
Debt Instrument [Line Items]
Debt instrument, quarterly principal payment	$ 6

PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Land and improvements	$ 192	$ 186
Buildings and improvements	794	733
Machinery, equipment and other	1,621	1,445
Construction-in-progress	163	141
Total	2,770	2,505
Accumulated depreciation	(1,191)	(1,017)
Property, plant and equipment—Net	$ 1,579	$ 1,488

INCOME TAXES - Narratives (Detail) - USD ($) $ in Millions	12 Months Ended
INCOME TAXES - Narratives (Detail) - USD ($) $ in Millions	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Income Tax Contingency [Line Items]
Statutory tax rate		21.00%	21.00%	21.00%
Net operating losses		$ 59.0	$ 52.0
US and non-US Tax Credit Carryforward		$ 9.0
US and non-US tax credit carryforward expiration period		2026
Effect of unrecognized tax benefits on effective tax rate		$ 23.0	14.0
Accrual for income tax penalties and interest		5.0	4.0
Deferred Federal Income Tax Expense (Benefit)		(32.0)	$ (6.0)	$ 28.0
Undistributed Earnings of Foreign Subsidiaries		30.0
Forecast
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Expected Reduction	$ 2.0
State
Income Tax Contingency [Line Items]
Net operating losses		$ 780.0
Minimum
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Year		2026
Maximum
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Year		2045
UNITED KINGDOM \| Foreign Country Jurisdiction
Income Tax Contingency [Line Items]
Net operating losses		$ 93.0
GERMANY \| Foreign Country Jurisdiction
Income Tax Contingency [Line Items]
Net operating losses		$ 66.0

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' DEFICIT (Parenthetical) - $ / shares	1 Months Ended		12 Months Ended
	Sep. 30, 2024	Nov. 30, 2023	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Statement of Stockholders' Equity [Abstract]
Dividends declared (in usd per share)	$ 75.00	$ 35.00	$ 90.00	$ 110.00	$ 0

DEBT - Issuance of $2,650 million of Senior Subordinated Notes due 2033 (Details) - USD ($) $ in Millions	May 20, 2025	Sep. 30, 2025
Debt Instrument [Line Items]
Debt instrument, face amount		$ 29,236.0
6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”) \| Senior Subordinated Notes
Debt Instrument [Line Items]
Debt instrument, face amount	$ 2,650.0
Interest rate	6.375%	6.375%
Debt instrument, redemption price, percentage	99.225%
Debt instrument, unamortized discount	$ 20.5
Debt issuance costs		$ 14.0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

EARNINGS PER SHARE (Tables)

12 Months Ended

Sep. 30, 2025

Earnings Per Share [Abstract]

Computation of Basic and Diluted Earnings Per Share (two-class method)

The following table sets forth the computation of basic and diluted earnings per share (in millions, except per share data) using the two-class method:


	Fiscal Years Ended September 30,
	2025		2024		2023
Numerator for earnings per share:
Net income	$	2,074	$	1,715	$	1,299
Less: Net income attributable to noncontrolling interests	—		(1)		(1)
Net income attributable to TD Group	2,074		1,714		1,298
Less: Dividends declared or paid on participating securities	(208)		(233)		(38)

Net income applicable to TD Group common stockholders—basic and diluted	$	1,866	$	1,481	$	1,260
Denominator for basic and diluted earnings per share under the two-class method:
Weighted-average common shares outstanding	56.3		55.8		54.9
Vested options deemed participating securities	1.9		2.0		2.3
Total shares for basic and diluted earnings per share	58.2		57.8		57.2



Earnings per share—basic and diluted (1)	$	32.08	$	25.62	$	22.03

(1)Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated using unrounded numbers.

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2025	Sep. 30, 2024
Statement of Financial Position [Abstract]
Common stock, par or stated value (in usd per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	224,400,000	224,400,000
Common stock, issued (in shares)	62,465,317	61,904,833
Treasury stock, common (in shares)	6,089,675	5,688,639

STOCK REPURCHASE PROGRAM	12 Months Ended
STOCK REPURCHASE PROGRAM	Sep. 30, 2025
Equity [Abstract]
STOCK REPURCHASE PROGRAM	STOCK REPURCHASE PROGRAM TD Group consists of 224,400,000 shares of $.01 par value common stock and 149,600,000 shares of $.01 par value preferred stock. The total number of shares of common stock issued at September 30, 2025 and 2024 was 62,465,317 and 61,904,833, respectively. The total number of shares held in treasury was 6,089,675 and 5,688,639 at September 30, 2025 and 2024, respectively. There were no shares of preferred stock outstanding at September 30, 2025 and 2024. The terms of the preferred stock have not been established. On January 27, 2022, the Board of Directors of the Company authorized a new stock repurchase program to permit repurchases of its outstanding common stock not to exceed $2,200 million in the aggregate (the “$2,200 million stock repurchase program”), replacing the $650 million stock repurchase program previously authorized by the Board of Directors on November 8, 2017, subject to any restrictions specified in the Credit Agreement and indentures governing the Company's existing Notes. There is no expiration date for this program. During fiscal 2025, the Company repurchased 401,036 shares of common stock at an average price of $1,246.71 per share, for a total amount of $500 million. The repurchased shares of common stock are classified as treasury stock in the statement of changes in stockholders' deficit. As of September 30, 2025, $788 million remained available for repurchase under the $2,200 million stock repurchase program. Subsequent Event – October Share Repurchase Activity – In October 2025, the Company repurchased 79,959 shares of common stock at an average price of $1,249.90 per share for a total amount of $100 million. Subsequent Event – Additional Share Repurchase Authorization – In November 2025, the Board of Directors authorized an additional $5,000 million in share repurchases of common stock permissible under the Company’s existing stock repurchase program, subject to any restrictions specified in the Credit Agreement and indentures governing the existing Subordinated and Secured Notes.

- Definition

The entire disclosure for equity.

+ References

+ Details

DOCUMENT AND ENTITY INFORMATION - USD ($)	12 Months Ended
DOCUMENT AND ENTITY INFORMATION - USD ($)	Sep. 30, 2025	Oct. 31, 2025	Mar. 28, 2025
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Sep. 30, 2025
Current Fiscal Year End Date	--09-30
Document Transition Report	false
Entity File Number	001-32833
Entity Registrant Name	TransDigm Group Incorporated
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	41-2101738
Entity Address, Address Line One	1350 Euclid Avenue,
Entity Address, Address Line Two	Suite 1600,
Entity Address, City or Town	Cleveland,
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	44115
City Area Code	216
Local Phone Number	706-2960
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	TDG
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 76,426,902,522
Entity Common Stock, Shares Outstanding		56,318,584
Documents Incorporated by Reference	Certain sections of the registrant’s definitive Proxy Statement to be filed in connection with its 2026 Annual Meeting of Shareholders expected to be held on March 5, 2026 are incorporated by reference into Part III of this Annual Report on Form 10-K.
Amendment Flag	false
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Entity Central Index Key	0001260221

REVENUE RECOGNITION

12 Months Ended

Sep. 30, 2025

Revenue Recognition [Abstract]

REVENUE RECOGNITION

TransDigm's sales are concentrated in the aerospace and defense industry. The Company’s customers include: distributors of aerospace components, commercial airlines, large commercial transport and regional and business aircraft original equipment manufacturers (“OEMs”), various armed forces of the U.S. and friendly foreign governments, defense OEMs, system suppliers, and various other industrial customers.

The Company recognizes revenue from contracts with customers using the five step model prescribed in ASC 606. A substantial portion of the Company's revenue is recorded at a point in time basis. Revenue is recognized from the sale of products or services when obligations under the terms of the contract are satisfied and control of promised goods or services have transferred to the customer. Control is transferred when the customer has the ability to direct the use of and obtain benefits from the goods or services. Revenue is measured at the amount of consideration the Company expects to be paid in exchange for goods or services.

In a limited number of contracts, control transfers to the customer over time, primarily in contracts where the customer is required to pay for the cost of both the finished and unfinished goods at the time of cancellation plus a reasonable profit relative to the work performed for products that were customized for the customer. Therefore, we recognize revenue over time for those agreements that have a right to margin and where the products being produced have no alternative use.

Based on our production cycle, it is generally expected that goods related to the revenue will be shipped and billed within twelve months. For revenue recognized over time, we estimate the amount of revenue attributable to a contract earned at a given point during the production cycle based on certain costs, such as materials and labor incurred to date, plus the expected profit, which is a cost-to-cost input method.

We consider the contractual consideration payable by the customer and assess variable consideration that may affect the total transaction price. Variable consideration is included in the estimated transaction price when there is a basis to reasonably estimate the amount, including whether the estimate should be constrained in order to avoid a significant reversal of revenue in a future period. These estimates are based on historical experience, anticipated performance under the terms of the contract and our best judgment at the time.

When contracts are modified to account for changes in contract specifications and requirements, the Company considers whether the modification either creates new or changes the existing enforceable rights and obligations. Contract modifications that are for goods or services that are not distinct from the existing contract, due to the significant integration with the original good or service provided, are accounted for as if they were part of that existing contract. The effect of a contract modification to an existing contract on the transaction price and our measure of progress for the performance obligation to which it relates, is recognized as an adjustment to revenue on a cumulative catch-up basis. When the modifications include additional performance obligations that are distinct and at relative stand-alone selling price, they are accounted for as a new contract and performance obligation, which are recognized prospectively.

The Company’s payment terms vary by the type and location of the customer and the products or services offered. The Company does not offer any payment terms that would meet the requirements for consideration as a significant financing component.

Shipping and handling fees and costs incurred in connection with products sold are recorded in cost of sales in the consolidated statements of income, and are not considered a performance obligation to our customers.

The Company pays sales commissions that relate to contracts for products or services that are satisfied at a point in time or over a period of one year or less and are expensed as incurred. These costs are reported as a component of selling and administrative expenses in the consolidated statements of income.

In fiscal 2025, 2024 and 2023, no customer individually accounted for 10% or more of the Company’s net sales.

Net sales to foreign customers, primarily in Western Europe, Canada and Asia, were $3,296 million, $2,908 million and $2,320 million during the fiscal years ended September 30, 2025, 2024 and 2023, respectively.

We have elected to adopt the practical expedient to not disclose the aggregate amount of transaction price allocated to performance obligations that are unsatisfied as of the end of the reporting period for performance obligations that are part of a contract with an original expected duration of one year or less.

Contract Assets and Liabilities – Contract assets reflect revenue recognized and performance obligations satisfied in advance of customer billing or reimbursable costs related to a specific contract. Contract liabilities (Deferred revenue) relate to payments received in advance of the satisfaction of performance under the contract. We receive payments from customers based on the terms established in our contracts. The following table summarizes our contract assets and liabilities balances (in millions):


	September 30, 2025		September 30, 2024
Contract assets, current (1)	$	280	$	270
Contract assets, non-current (2)	94		31
Total contract assets	374		301
Contract liabilities, current (3)	143		168
Contract liabilities, non-current (4)	7		9
Total contract liabilities	150		177
Net contract assets	$	224	$	124

(1)Included in prepaid expenses and other on the consolidated balance sheets.

(2)Included in other non-current assets on the consolidated balance sheets.

(3)Included in accrued and other current liabilities on the consolidated balance sheets.

(4)Included in other non-current liabilities on the consolidated balance sheets.

The increase in non-current contract assets is attributable to expected customer billing of certain contracts exceeding one year from September 30, 2025. For the fiscal year ended September 30, 2025, the revenue recognized that was included in the contract liability balance at the beginning of the fiscal year was approximately $125 million.

Refer to Note 15, “Segments,” for disclosures related to the disaggregation of revenue.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

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DEBT - Issuance of $2,000 Subordinated Notes due 2034 (Details) - USD ($) $ in Millions	Sep. 30, 2025	Aug. 19, 2025
Debt Instrument [Line Items]
Debt instrument, face amount	$ 29,236
6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”) \| Senior Subordinated Notes
Debt Instrument [Line Items]
Debt instrument, face amount		$ 2,000
Issuance price of principal amount, percentage		100.00%
Interest rate	6.75%	6.75%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

VALUATION AND QUALIFYING ACCOUNTS (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 32	$ 31	$ 35
Charged to Costs and Expenses	4	3	4
Acquisitions & Purchase Price Adjustments	0	0	0
Deductions from Reserve	(11)	(2)	(8)
Balance at End of Period	25	32	31
Reserve for excess and obsolete inventory
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	236	209	196
Charged to Costs and Expenses	51	35	20
Acquisitions & Purchase Price Adjustments	2	11	0
Deductions from Reserve	(19)	(19)	(7)
Balance at End of Period	270	236	209
Valuation Allowance of Deferred Tax Assets
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	318	227	137
Charged to Costs and Expenses	138	91	90
Acquisitions & Purchase Price Adjustments	0	0	0
Deductions from Reserve	0	0	0
Balance at End of Period	$ 456	$ 318	$ 227

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

LEASES - Weighted-Average Term and Discount Rate Remaining (Details)	Sep. 30, 2025
Leases [Abstract]
Operating Lease, Weighted Average Remaining Lease Term	6 years 4 months 24 days
Finance Lease, Weighted Average Remaining Lease Term	19 years 9 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent	5.70%
Finance Lease, Weighted Average Discount Rate, Percent	7.00%

DERIVATIVES AND HEDGING ACTIVITIES

12 Months Ended

Sep. 30, 2025

Derivative Instruments and Hedging Activities Disclosure [Abstract]

DERIVATIVES AND HEDGING ACTIVITIES

The Company is exposed to, among other things, the impact of changes in foreign currency exchange rates and interest rates in the normal course of business. The Company’s risk management program is designed to manage the exposure and volatility arising from these risks, and utilizes derivative financial instruments to offset a portion of these risks. The Company uses derivative financial instruments only to the extent necessary to hedge identified business risks and does not enter into such transactions for trading purposes. The Company generally does not require collateral or other security with counterparties to these financial instruments and is therefore subject to credit risk in the event of nonperformance; however, the Company monitors credit risk and currently does not anticipate nonperformance by other parties. These derivative financial instruments do not subject the Company to undue risk, as gains and losses on these instruments generally offset gains and losses on the underlying assets, liabilities, or anticipated transactions that are being hedged. The Company has agreements with each of its swap, cap and collar counterparties that contain a provision whereby if the Company defaults on the Credit Agreement, the Company could also be declared in default on its swaps, cap and collars resulting in an acceleration of settlement under the swaps, cap and collars.

All derivative financial instruments are recorded at fair value in the consolidated balance sheets. For a derivative that has not been designated as an accounting hedge, the change in the fair value is recognized immediately through earnings. For a derivative that has been designated as an accounting hedge of an existing asset or liability (a fair value hedge), the change in the fair value of both the derivative and underlying asset or liability is recognized immediately through earnings. For a derivative designated as an accounting hedge of an anticipated transaction (a cash flow hedge), the change in the fair value is recorded on the consolidated balance sheets in accumulated other comprehensive loss to the extent the derivative is effective in mitigating the exposure related to the anticipated transaction. The change in the fair value related to the ineffective portion of the hedge, if any, is immediately recognized in earnings. The amount recorded within accumulated other comprehensive loss is reclassified into earnings in the same period during which the underlying hedged transaction affects earnings.

Interest Rate Swap, Cap and Collar Agreements – Interest rate swap, cap and collar agreements are used to manage interest rate risk associated with floating rate borrowings, specifically the term loans, under our Credit Agreement. These agreements involve the receipt of floating rate amounts in exchange for fixed rate interest payments over the term of the agreements without an exchange of the underlying principal amount. The agreements utilized by the Company effectively modify the Company’s exposure to interest rate risk by converting a portion of the Company’s floating rate debt to a fixed rate basis from the effective date through the maturity date of the respective interest rate swap, cap and collar agreements, thereby reducing the impact of interest rate movements on future interest expense.

During the fourth quarter of fiscal 2025, we entered into forward starting interest rate collar agreements and interest rate swap agreements. The interest rate collar agreements, aggregating to a notional amount of $2,750 million, establish a range where we will pay the counterparties if the three-month Term SOFR rate falls below the established floor rate, and the counterparties will pay us if the three-month Term SOFR rate exceeds the ceiling rate as summarized in the table below. The collar will settle quarterly from the effective date through the maturity date. No payments or receipts will be exchanged on the interest rate collar contracts unless interest rates rise above or fall below the contracted ceiling or floor rates. The interest rate swap agreements hedge the variable interest rates on the Company's floating rate debt exposures for a fixed rate based on an aggregate notional amount of $2,750 million. The swap will settle quarterly from the effective date through the maturity date. The Company does not have any interest rate cap agreements as of September 30, 2025.

The tables below summarize the key terms of the swaps and collars as of September 30, 2025 (aggregated by effective date).

Interest rate swap agreements:

Aggregate Notional Amount (in millions)

Effective Date

Maturity Date

Conversion of Related Variable Rate Debt subject to Term SOFR to Fixed Rate of:

$700

9/30/2025

9/30/2027

3.22% plus applicable margin percentage

$125

9/30/2027

9/30/2029

3.11% plus applicable margin percentage

$1,025

9/30/2027

9/30/2029

3.12% plus applicable margin percentage

$900

9/30/2027

9/30/2029

3.14% plus applicable margin percentage

Interest rate collar agreements:

Aggregate Notional Amount (in millions)

Effective Date

Maturity Date

Offsets Variable Rate Debt Attributable to Fluctuations Below and Above:

$1,100

3/31/2025

9/30/2026

Three-month Term SOFR rate of 2.00% (floor) and 3.50% (cap)

$500

9/30/2025

9/30/2026

Three-month Term SOFR rate of 2.00% (floor) and 3.50% (cap)

$1,338

9/30/2025

9/30/2027

Three-month Term SOFR rate of 2.50% (floor) and 4.50% (cap)

$700

9/30/2025

9/30/2027

Three-month Term SOFR rate of 2.00% (floor) and 3.91% (cap)

$1,550

9/30/2026

9/30/2027

Three-month Term SOFR rate of 2.50% (floor) and 4.50% (cap)

$2,050

9/30/2027

9/30/2029

Three-month Term SOFR rate of 2.21% (floor) and 4.25% (cap)

These derivative instruments qualify as effective cash flow hedges under U.S. GAAP. For our cash flow hedges, the effective portion of the gain or loss from the financial instruments is initially reported as a component of accumulated other comprehensive loss in stockholders’ deficit and subsequently reclassified into earnings in the same line as the hedged item in the same period or periods during which the hedged item affects earnings. As the interest rate swap, cap and collar agreements are used to manage interest rate risk, any gains or losses from the derivative instruments that are reclassified into earnings are recognized in interest expense-net in the consolidated statements of income. Cash flows related to the derivative contracts are included in cash flows from operating activities on the consolidated statements of cash flows.

Certain derivative asset and liability balances are offset where master netting agreements provide for the legal right of setoff. For classification purposes, we record the net fair value of each type of derivative position that is expected to settle in less than one year with each counterparty as a net current asset or liability and each type of long-term position as a net non-current asset or liability. The amounts shown in the table below represent the gross amounts of recognized assets and liabilities, the amounts offset in the consolidated balance sheets and the net amounts of assets and liabilities presented therein (in millions):


	September 30, 2025				September 30, 2024
	Asset		Liability		Asset		Liability
Interest rate cap agreement	$	—	$	—	$	20	$	1
Interest rate collar agreements	7		3		3		8
Interest rate swap agreements	8		—		34		1


Net derivatives as classified in the consolidated balance sheets (1)	$	15	$	3	$	57	$	10

(1)Refer to Note 11, “Fair Value Measurements,” for the consolidated balance sheets classification of the Company’s interest rate swap, cap and collar agreements.

Based on the fair value amounts determined as of September 30, 2025, the estimated net amount of existing losses (gains) and caplet amortization expected to be reclassified into interest expense-net within the next twelve months is approximately $7 million.

Foreign Currency Forward Exchange Contracts – The Company transacts business in various foreign currencies, which subjects the Company’s cash flows and earnings to exposure related to changes in foreign currency exchange rates. These exposures arise primarily from purchases or sales of products and services from third parties. Foreign currency forward exchange contracts provide for the purchase or sale of foreign currencies at specified future dates at specified exchange rates, and are used to offset changes in the fair value of certain assets or liabilities or forecasted cash flows resulting from transactions denominated in foreign currencies. At September 30, 2025, the Company has outstanding foreign currency forward exchange contracts to sell U.S. dollars with notional amounts of $118 million. The maximum duration of the Company’s foreign currency cash flow hedge contracts at September 30, 2025 is twelve months. These notional values consist of contracts for the Canadian dollar and the euro and are stated in U.S. dollar equivalents at spot exchange rates at the respective trade dates. Amounts related to foreign currency forward exchange contracts included in accumulated other comprehensive loss in stockholders' deficit are reclassified into net sales when the hedged transaction settles. As of September 30, 2025, the Company expects to record a net loss of approximately $2 million on foreign currency forward exchange contracts designated as cash flow hedges to net sales over the next twelve months

- Definition

The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.

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+ Details

DEBT - Future Maturities of Long-Term Debt (Detail) $ in Millions	Sep. 30, 2025 USD ($)
Debt Disclosure [Abstract]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 116
Long-term Debt, Maturities, Repayments of Principal in Year Two	116
Long-term Debt, Maturities, Repayments of Principal in Year Three	2,216
Long-term Debt, Maturities, Repayments of Principal in Year Four	4,812
Long-term Debt, Maturities, Repayments of Principal in Year Five	3,478
Long-term Debt, Maturities, Repayments of Principal after Year Five	18,498
Debt Instrument, Face Amount	$ 29,236

STOCK-BASED COMPENSATION - Narratives (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Oct. 03, 2019	Oct. 02, 2014	Mar. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock and deferred compensation expense	$ 152,000,000	$ 188,000,000	$ 135,000,000
Stock option weighted-average grant date fair value	$ 549.03	$ 397.31	$ 251.73
Unrecognized compensation cost related to non-vested awards expected to vest	$ 208,000,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 9 months 18 days
Fair value of options vested	$ 107,000,000	$ 97,000,000	$ 80,000,000
Dividend equivalent payments, current (Note 16)	59,000,000	180,000,000
Dividend Equivalent Payments on Certain Stock Options, Non-current	76,000,000
Share-Based Payment Arrangement, Tax Benefit	24,000,000	24,000,000	15,000,000
Share-Based Payment Arrangement, Noncurrent Liabilities, Other	102,000,000
Dividend Equivalent Payments	208,000,000	233,000,000	38,000,000
Payments of special dividends	5,073,000,000
Cash dividend equivalent payments	159,000,000
Other Non-Current Liabilities
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock and deferred compensation expense	2,000,000	54,000,000	23,000,000
Additional Paid-In Capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock and deferred compensation expense	$ 150,000,000	134,000,000	112,000,000
2019 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock				4,000,000
Shares available for award	3,210,451
2014 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock					5,000,000
2006 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock						8,119,668
2003 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options exercised	$ 600,000,000	$ 794,000,000	$ 500,000,000
S 2025 Dividends
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends declared (in dollars per share)	$ 90.00
Performance Vested Stock Options \| 2019 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for award	346,664
Stock-based compensation activity (in shares)	26,420
Weighted-Average Exercise Price Per Option, Exercised	$ 656.47
Number of Options Exercisable at end of period	93,696
Weighted-Average Exercise Price Per Option, Exercisable	$ 724.47
Weighted-Average Remaining Contractual Term, Exercisable, years	7 years 7 months 6 days
Aggregate Intrinsic Value, Exercisable	$ 55,613,261
Performance Vested Stock Options \| 2014 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for award	0
Stock-based compensation activity (in shares)	462,368
Weighted-Average Exercise Price Per Option, Exercised	$ 288.80
Number of Options Exercisable at end of period	2,429,832
Weighted-Average Exercise Price Per Option, Exercisable	$ 376.64
Weighted-Average Remaining Contractual Term, Exercisable, years	3 years 7 months 6 days
Aggregate Intrinsic Value, Exercisable	$ 2,287,395,248

TRADE ACCOUNTS RECEIVABLE

12 Months Ended

Sep. 30, 2025

Receivables [Abstract]

TRADE ACCOUNTS RECEIVABLE

Trade accounts receivable consist of the following (in millions):


	September 30, 2025		September 30, 2024
Trade accounts receivable—gross	$	1,642	$	1,413
Allowance for uncollectible accounts	(25)		(32)
Trade accounts receivable—Net	$	1,617	$	1,381

Allowance for Credit Losses – The Company's allowance for credit losses is the allowance for uncollectible accounts. The allowance for uncollectible accounts reduces the trade accounts receivable balance to the estimated net realizable value equal to the amount that is expected to be collected.