ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Accumulated Other Comprehensive Income (Loss), Net of Taxes (Details) - USD ($)
$ in Millions

3 Months Ended

Dec. 27, 2025

Dec. 28, 2024

AOCI Attributable to Parent, Net of Tax [Roll Forward]

Balance at beginning of period

$ (9,679)

$ (6,283)

Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax

Pension and postretirement benefit plans adjustment, net of tax

Foreign currency translation adjustment

(227)

Other Comprehensive Income (Loss), Net of Tax

(205)

Balance at end of period

(9,263)

(6,251)

Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax

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)

Derivative, Gain (Loss) on Derivative, Tax Expense (Benefit)

(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

Derivative, Gain (Loss) on Derivative, Tax Expense (Benefit)

Accumulated Other Comprehensive Loss

AOCI Attributable to Parent, Net of Tax [Roll Forward]

Balance at beginning of period

(10)

(42)

Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax

Pension and postretirement benefit plans adjustment, net of tax

Foreign currency translation adjustment

(227)

Other Comprehensive Income (Loss), Net of Tax

^[1]

(205)

Balance at end of period

(247)

Unrealized losses on derivatives (1)

AOCI Attributable to Parent, Net of Tax [Roll Forward]

Balance at beginning of period

^[2]

(4)

Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax

^[1],[2]

Balance at end of period

^[2]

Pension and post-retirement benefit plans adjustment (2)

AOCI Attributable to Parent, Net of Tax [Roll Forward]

Balance at beginning of period

^[3]

(2)

Pension and postretirement benefit plans adjustment, net of tax

^[1],[3]

Balance at end of period

^[3]

(2)

Foreign currency translation adjustment (3)

AOCI Attributable to Parent, Net of Tax [Roll Forward]

Balance at beginning of period

^[4]

(4)

(62)

Foreign currency translation adjustment

^[1],[4]

(227)

Balance at end of period

^[4]

$ 22

$ (289)

[1]	Presented net of reclassifications out of accumulated other comprehensive income (loss) 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 $1 million (net of taxes of $1 million), respectively, for the thirteen week period ended December 27, 2025 and less than $(1) million (net of taxes of less than $(1) million) and $1 million (net of taxes of less than $1 million), respectively, for the thirteen week period ended December 28, 2024
[2]	Represents unrealized gains (losses) on derivatives designated and qualifying as cash flow hedges, net of tax (expense) benefit, of $2 million and $7 million for the thirteen week periods ended December 27, 2025 and December 28, 2024, respectively
[3]	There were no material pension liability adjustments, net of taxes, related to activity for the defined pension plans and postretirement benefit plans for the thirteen week periods ended December 27, 2025 and December 28, 2024.
[4]	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.

TransDigm Group INC 10-Q