TransDigm (TDG) 10-Q 8 Aug 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	9 Months Ended
	Jun. 30, 2018	Jul. 31, 2018
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	TDG
Entity Registrant Name	TRANSDIGM GROUP INC
Entity Central Index Key	1,260,221
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		52,628,694

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 1,853,373	$ 650,561
Trade accounts receivable - Net	658,168	636,127
Inventories - Net	815,251	730,681
Assets held-for-sale	0	77,500
Prepaid expenses and other	58,610	38,683
Total current assets	3,385,402	2,133,552
PROPERTY, PLANT AND EQUIPMENT - NET	380,475	324,924
GOODWILL	6,209,247	5,745,338
OTHER INTANGIBLE ASSETS - NET	1,715,074	1,717,862
OTHER	114,279	53,985
TOTAL ASSETS	11,804,477	9,975,661
CURRENT LIABILITIES:
Current portion of long-term debt	75,793	69,454
Short-term borrowings - trade receivable securitization facility	299,956	299,587
Accounts payable	155,937	148,761
Accrued liabilities	285,484	335,888
Liabilities held-for-sale	0	17,304
Total current liabilities	817,170	870,994
LONG-TERM DEBT	12,516,010	11,393,620
DEFERRED INCOME TAXES	357,680	500,949
OTHER NON-CURRENT LIABILITIES	212,097	161,302
Total liabilities	13,902,957	12,926,865
STOCKHOLDERS’ DEFICIT:
Common stock - $.01 par value; authorized 224,400,000 shares; issued 56,717,525 and 56,093,659 at June 30, 2018 and September 30, 2017, respectively	567	561
Additional paid-in capital	1,171,549	1,095,319
Accumulated deficit	(2,471,575)	(3,187,220)
Accumulated other comprehensive loss	(23,717)	(85,143)
Treasury stock, at cost; 4,161,326 and 4,159,207 shares at June 30, 2018 and September 30, 2017, respectively	(775,304)	(774,721)
Total stockholders’ deficit	(2,098,480)	(2,951,204)
TOTAL LIABILITIES AND STOCKHOLDERS’ DEFICIT	$ 11,804,477	$ 9,975,661

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets Parenthetical - $ / shares	Jun. 30, 2018	Sep. 30, 2017
Statement of Financial Position [Abstract]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	224,400,000	224,400,000
Common Stock, Shares, Issued	56,717,525	56,093,659
Treasury Stock, Shares	4,161,326	4,159,207

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
NET SALES	$ 980,662	$ 897,655	$ 2,761,692	$ 2,580,401
COST OF SALES	411,142	377,959	1,181,448	1,127,013
GROSS PROFIT	569,520	519,696	1,580,244	1,453,388
SELLING AND ADMINISTRATIVE EXPENSES	113,019	108,104	327,073	310,677
AMORTIZATION OF INTANGIBLE ASSETS	19,224	23,259	53,793	70,822
INCOME FROM OPERATIONS	437,277	388,333	1,199,378	1,071,889
INTEREST EXPENSE - NET	167,577	152,141	489,776	445,986
REFINANCING COSTS	4,159	345	5,910	35,936
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	265,541	235,847	703,692	589,967
INCOME TAX PROVISION	48,150	66,015	(27,550)	145,573
INCOME FROM CONTINUING OPERATIONS	217,391	169,832	731,242	444,394
LOSS FROM DISCONTINUED OPERATIONS, NET OF TAX	(145)	(779)	(2,943)	(965)
NET INCOME	217,246	169,053	728,299	443,429
NET INCOME APPLICABLE TO COMMON STOCK	$ 217,246	$ 169,053	$ 672,151	$ 347,458
Net earnings per share:
Net earnings per share from continuing operations - basic and diluted	$ 3.91	$ 3.09	$ 12.14	$ 6.25
Net loss per share from discontinued operations - basic and diluted	0	(0.01)	(0.05)	(0.02)
Net earnings per share	3.91	3.08	12.09	6.23
Cash dividends paid per common share	$ 0	$ 0	$ 0	$ 24
Weighted-average shares outstanding:
Basic and diluted (in shares)	55,597	54,890	55,598	55,773

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Net income	$ 217,246	$ 169,053	$ 728,299	$ 443,429
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(32,543)	24,525	(4,355)	4,523
Interest rate swap and cap agreements	2,307	(8,386)	65,781	32,568
Other comprehensive (loss) income, net of tax	(30,236)	16,139	61,426	37,091
TOTAL COMPREHENSIVE INCOME	$ 187,010	$ 185,192	$ 789,725	$ 480,520

Condensed Consolidated Stateme6

Condensed Consolidated Statement of Changes in Stockholders' Deficit - 9 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income	Treasury Stock
BALANCE (in shares) at Sep. 30, 2017	56,093,659	56,093,659
BALANCE (in shares) at Sep. 30, 2017	(4,159,207)					(4,159,207)
BALANCE at Sep. 30, 2017	$ (2,951,204)	$ 561	$ 1,095,319	$ (3,187,220)	$ (85,143)	$ (774,721)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Unvested dividend equivalents and other	(12,654)			(12,654)
Compensation expense recognized for employee stock options and restricted stock	35,460		35,460
Exercise of employee stock options, restricted stock activity and other, net (in shares)		623,361				(2,119)
Exercise of employee stock options, restricted stock activity and other, net	40,044	$ 6	40,621			$ (583)
Common stock issued (in shares)		505
Common stock issued	149		149
Net income	728,299			728,299
Foreign currency translation adjustments	(4,355)				(4,355)
Interest rate swaps and caps, net of tax	$ 65,781				65,781
BALANCE (in shares) at Jun. 30, 2018	56,717,525	56,717,525
BALANCE (in shares) at Jun. 30, 2018	(4,161,326)					(4,161,326)
BALANCE at Jun. 30, 2018	$ (2,098,480)	$ 567	$ 1,171,549	$ (2,471,575)	$ (23,717)	$ (775,304)

Condensed Consolidated Stateme7

Condensed Consolidated Statement of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
OPERATING ACTIVITIES:
Net income	$ 728,299	$ 443,429
Net loss from discontinued operations	2,943	965
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	41,248	37,581
Amortization of intangible assets and product certification costs	54,286	71,495
Amortization of debt issuance costs, original issue discount and premium	16,179	15,530
Refinancing costs	5,910	35,936
Non-cash equity compensation	36,411	32,707
Deferred income taxes	(166,783)	270
Changes in assets/liabilities, net of effects from acquisitions of businesses:
Trade accounts receivable	(861)	(21,195)
Inventories	(21,992)	(325)
Income taxes receivable/payable	6,730	(12,782)
Other assets	(2,500)	(4,104)
Accounts payable	724	(12,342)
Accrued interest	6,670	741
Accrued and other liabilities	(16,354)	(32,690)
Net cash provided by operating activities	690,910	555,216
INVESTING ACTIVITIES:
Capital expenditures	(50,097)	(55,671)
Payments made in connection with acquisitions	(582,262)	(135,507)
Proceeds (payments made) from sale (purchase) of discontinued operations	57,686	(79,695)
Net cash used in investing activities	(574,673)	(270,873)
FINANCING ACTIVITIES:
Proceeds from exercise of stock options	40,621	18,046
Special dividend and dividend equivalent payments	(56,148)	(1,376,034)
Treasury stock purchased	0	389,821
Proceeds from term loans, net	12,779,772	1,132,755
Repayments on term loans	(12,155,198)	(48,453)
Proceeds from senior subordinated notes due 2026, net	490,411	0
Cash tender and redemption of senior subordinated notes due 2021, including premium	0	(528,847)
Proceeds from additional senior subordinated notes due 2025, net	0	300,517
Other	(9,904)	(10,777)
Net cash provided by (used in) financing activities	1,089,554	(902,614)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	(2,979)	1,833
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	1,202,812	(616,438)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	650,561	1,586,994
CASH AND CASH EQUIVALENTS, END OF PERIOD	1,853,373	970,556
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid during the period for interest	469,667	434,295
Cash paid during the period for income taxes	$ 123,597	$ 157,899

DESCRIPTION OF THE BUSINESS

DESCRIPTION OF THE BUSINESS	9 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
DESCRIPTION OF THE BUSINESS	DESCRIPTION OF THE BUSINESS Description of the Business – 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 for use on 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 components. 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.” Major product offerings, substantially all of which are ultimately provided to end-users in the aerospace industry, include mechanical/electro-mechanical actuators and controls, ignition systems and engine technology, specialized pumps and valves, power conditioning devices, specialized AC/DC electric motors and generators, NiCad batteries and chargers, engineered latching and locking devices, rods and locking devices, engineered connectors and elastomers, databus and power controls, cockpit security components and systems, specialized cockpit displays, aircraft audio systems, specialized lavatory components, seat belts and safety restraints, engineered interior surfaces and related components, lighting and control technology, military personnel parachutes, high performance hoists, winches and lifting devices, and cargo loading, handling and delivery systems.

UNAUDITED INTERIM FINANCIAL INF

UNAUDITED INTERIM FINANCIAL INFORMATION	9 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
UNAUDITED INTERIM FINANCIAL INFOMRATION	UNAUDITED INTERIM FINANCIAL INFORMATION The financial information included herein is unaudited; however, the information reflects all adjustments (consisting of normal recurring adjustments) that are, in the opinion of management, necessary for a fair presentation of the Company’s financial position and results of operations and cash flows for the interim periods presented. These financial statements and notes should be read in conjunction with the financial statements and related notes for the year ended September 30, 2017 included in TD Group’s Form 10-K filed on November 13, 2017. As disclosed therein, the Company’s annual consolidated financial statements were prepared in conformity with generally accepted accounting principles in the United States (“GAAP”). The September 30, 2017 condensed consolidated balance sheet was derived from TD Group’s audited financial statements. The results of operations for the thirty-nine week period ended June 30, 2018 are not necessarily indicative of the results to be expected for the full year. Certain reclassifications have been made to the prior year financial statements to conform to current year presentation related to the designation of Schroth as discontinued operations beginning in the fourth quarter of fiscal 2017 (refer to Note 14, "Discontinued Operations," for further information) and an organizational realignment effective October 1, 2017 of certain businesses comprising the Power & Control and the Non-Aviation segments.

ACQUISITIONS AND DIVESTITURES

ACQUISITIONS AND DIVESTITURES	9 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS AND DIVESTITURES During the thirty-nine week period ended June 30, 2018 , the Company completed the acquisitions of Extant Components Group Holdings, Inc. ("Extant") and the Kirkhill elastomers business ("Kirkhill") from Esterline Technologies. During the fiscal year ended September 30, 2017 , the Company completed the acquisitions of three separate aerospace product lines (collectively, the "Third Quarter 2017 Acquisitions"). The Company accounted for the acquisitions using the acquisition method and included the results of operations of the acquisitions in its condensed consolidated financial statements from the effective date of each acquisition. As of June 30, 2018 , the one-year measurement period is open for Extant and Kirkhill; therefore, the assets acquired and liabilities assumed related to these acquisitions are subject to adjustment until the end of their respective one-year measurement periods. The Company is in the process of obtaining a third-party valuation of certain intangible assets and tangible assets and liabilities of Kirkhill and Extant. Pro forma net sales and results of operations for the acquisitions had they occurred at the beginning of the applicable thirty-nine week period ended June 30, 2018 or July 1, 2017 are not material and, accordingly, are not provided. The acquisitions 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 strategies (obtaining profitable new business, improving our cost structure, and providing highly engineered value-added products to customers). The purchase price paid for each acquisition reflects the current earnings before interest, taxes, depreciation and amortization (EBITDA) and cash flows, as well as the future EBITDA and cash flows expected to be generated by the business, 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 . Extant – On April 24, 2018, the Company acquired all of the outstanding stock of Extant for a total purchase price of approximately $532.5 million in cash, which is net of a $0.2 million working capital settlement received in the third quarter of fiscal 2018. Extant provides a broad range of proprietary aftermarket products and repair and overhaul services to the aerospace and defense end markets. Extant owns or exclusively licenses in excess of 2,500 assemblies and sub-assemblies on over 70 active platforms. Extant is included in TransDigm's Power and Control segment. Prior to the Company's acquisition of Extant, Extant was owned by an equity fund sponsored by Warburg Pincus LLC. Michael Graff, a director of TransDigm, is a managing director of Warburg Pincus LLC and was chairman of the board of Extant. Robert Henderson, Vice Chairman of TransDigm, was also on the board of Extant and owned less than 2% of Extant on a fully diluted basis. In addition, Mr. Graff, Mr. W. Nicholas Howley, TransDigm's Executive Chairman, and Messrs. Douglas Peacock and David Barr, directors of TransDigm, each had minority interests of less than 1% in the Warburg Pincus LLC fund that owned Extant. The total purchase price of Extant was allocated to the underlying assets acquired and liabilities assumed based upon management’s estimated fair values at the date of acquisition. To the extent the purchase price exceeded the estimated fair value of the net identifiable tangible and intangible assets acquired, such excess was allocated to goodwill. The following table summarizes the purchase price allocation of the estimated fair values of the assets acquired and liabilities assumed at the transaction date (in thousands). Assets acquired: Current assets, excluding cash acquired $ 58,021 Property, plant, and equipment 4,124 Intangible assets 36,000 Goodwill 460,707 Other 86 Total assets acquired 558,938 Liabilities assumed: Current liabilities 9,213 Other noncurrent liabilities 17,226 Total liabilities assumed 26,439 Net assets acquired $ 532,499 The Company expects that approximately $44 million of goodwill recognized for the acquisition will be deductible for tax purposes over 15 years and approximately $417 million of goodwill recognized for the acquisition will not be deductible for tax purposes. Kirkhill – On March 15, 2018, the Company acquired the assets and certain liabilities of the Kirkhill elastomers business from Esterline Technologies for a total purchase price of approximately $49.3 million , which is net of a $0.6 million working capital settlement received in the third quarter of fiscal 2018. Kirkhill's products are primarily proprietary, sole source with significant aftermarket content and used in a broad variety of most major commercial transport and military platforms. Kirkhill is included in TransDigm's Airframe segment. The Company expects that no goodwill recognized for the acquisition will be deductible for tax purposes. Third Quarter 2017 Acquisitions – The Third Quarter 2017 Acquisitions were acquired for an aggregate purchase price of approximately $106.7 million in cash, which includes working capital settlements totaling $1.0 million paid in the third and fourth quarters of fiscal 2017 and an earn-out of $0.4 million paid in the second quarter of fiscal 2018. All three product lines consist primarily of proprietary, sole source products with significant aftermarket content. The products include highly engineered aerospace controls, quick disconnect couplings, and communication electronics. Each product line acquired was consolidated into an existing TransDigm reporting unit within TransDigm's Power & Control segment. Approximately $66 million of goodwill recognized for the acquisitions is deductible for tax purposes over 15 years and approximately $9 million of goodwill recognized for the acquisitions is not deductible for tax purposes. Schroth – On February 22, 2017, the Company acquired all of the outstanding stock of Schroth Safety Products GmbH and certain aviation and defense assets and liabilities from subsidiaries of Takata Corporation (collectively, "Schroth"), for a total purchase price of approximately $89.7 million , which consisted primarily of $79.7 million paid in cash during fiscal 2017 and an approximately $9.0 million indemnity holdback, of which $8.5 million was paid in April 2018. In connection with the settlement of a Department of Justice investigation into the competitive effects of the acquisition, during the fourth quarter of 2017, the Company committed to dispose of the Schroth business. Therefore, Schroth was classified as held-for-sale beginning in the fourth quarter of 2017. The results of operations of Schroth are reflected as discontinued operations in the accompanying condensed consolidated financial statements. On January 26, 2018, the Company completed the sale of Schroth in a management buyout to a private equity fund and certain members of Schroth management for approximately $61.4 million , which includes a working capital adjustment of $0.3 million that was settled in July 2018. Further disclosure related to Schroth’s discontinued operations is included in Note 14.

RECENT ACCOUNTING PRONOUNCEMENT

RECENT ACCOUNTING PRONOUNCEMENTS	9 Months Ended
	Jun. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, which created a new topic in the Accounting Standards Codification (“ASC”) 606, “Revenue From Contracts With Customers .” In addition to superseding and replacing nearly all existing U.S. GAAP revenue recognition guidance, including industry-specific guidance, ASC 606 establishes a new control-based revenue recognition model. The new revenue standards may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized as of the date of adoption. The guidance is effective for the Company for annual reporting periods, including interim periods therein, beginning October 1, 2018, which will be the Company’s date of adoption. The Company will use the modified retrospective method. The Company is continuing to evaluate the impact of the standard. For each reporting unit, we have evaluated a representative sample of contracts and other agreements with our customers and evaluated the provisions contained within these contracts and agreements in consideration of the five step model specified within ASC 606. We are in the process of documenting the impact of the standard on our current accounting policies and practices in order to identify material differences, if any, that would result from applying the new requirements to our revenue contracts. We continue to make progress on our assessment of ASC 606 and are also in the process of evaluating the impact on changes to our business processes, systems, and controls to support recognition and disclosure requirements under ASC 606. In February 2016, the FASB issued ASU 2016-02, “Leases (ASC 842),” which will require that a lessee recognize assets and liabilities on the balance sheet for all leases with a lease term of more than twelve months, with the result being the recognition of a right of use asset and a lease liability. Additionally, in July 2018, the FASB issued ASU 2018-10, "Codification Improvements to ASC 842, Leases" which provides narrow amendments to clarify how to apply certain aspects of the new leases standard. The new leases standard guidance is effective for the Company for annual reporting periods, including interim periods therein, beginning October 1, 2019, with early adoption permitted. The Company is currently evaluating the impact of adopting this standard on its consolidated financial statements and disclosures. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments (ASU 2016-13)," which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. ASU 2016-13 is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted for annual and interim periods beginning after December 15, 2018. The Company is currently evaluating the impact of adopting this standard on its consolidated financial statements and disclosures. In August 2016, the FASB issued ASU 2016-15, "Statement of Cash Flows—Classification of Certain Cash Receipts and Cash Payments," which clarifies existing guidance related to accounting for cash receipts and cash payments and classification on the statement of cash flows. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, with early adoption permitted. The Company elected to early adopt this standard in the fourth quarter of fiscal 2017. The adoption of this standard did not have a material impact on its consolidated statement of cash flows. In January 2017, the FASB issued ASU 2017-04, “Simplifying the Test for Goodwill Impairment,” to eliminate Step 2 from the goodwill impairment test in order to simplify the subsequent measurement of goodwill. The guidance is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The adoption of this standard is not expected to have a material impact on its consolidated financial statements and disclosures. In March 2017, the FASB issued ASU 2017-07, "Compensation—Retirement Benefits (ASC 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost," that will change how employers that sponsor defined benefit and/or other postretirement benefit plans present the net periodic benefit cost in the income statement. Under the new guidance, employers will present the service cost component of the net periodic benefit cost in the same income statement line item(s) as other employee compensation costs arising from services rendered during the period. In addition, only the service cost component will be eligible for capitalization in assets. Employers will present the other components separately from the line item(s) that includes the service cost and outside of any subtotal of operating income, if one is presented. Employers will have to disclose the line(s) used to present the other components of net periodic benefit cost, if the components are not presented separately in the income statement.The standard is effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within the fiscal year. Early adoption is permitted, including adoption in any interim period for which financial statements have not yet been issued. The adoption of this standard is not expected to have a material impact on our consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, "Compensation—Stock Compensation (ASC 718): Scope of Modification Accounting," which provides clarity on which changes to the terms or conditions of share-based payment awards require an entity to apply the modification accounting provisions required in ASC 718. The standard is effective for all entities for annual periods beginning after December 15, 2017, with early adoption permitted, including adoption in any interim period for which financial statements have not yet been issued. The adoption of this standard is not expected to have a material impact on our consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, “Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities,” which amends the FASB’s hedge accounting model to enable entities to better portray their risk management activities in financial statements. The guidance eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in the fair value of a hedging instrument to be presented in the same income statement line as the hedged item. The guidance also eases certain documentation and assessment requirements and modifies the accounting for components excluded from the assessment of hedge effectiveness. ASU 2017-12 is effective for the Company for annual reporting periods, including interim periods therein, beginning October 1, 2018, with early adoption permitted. As early adoption is permissible, the Company adopted the pronouncement beginning October 1, 2017. Changes were applied prospectively in accordance with the standard and prior periods were not adjusted. The adoption of this standard did not have a material impact on our consolidated financial statements and disclosures. In February 2018, the FASB issued ASU 2018-02, "Income Statement - Reporting Comprehensive Income (ASC 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income," which gives entities the option to reclassify tax effects stranded in accumulated other comprehensive income as a result of the Tax Cuts and Jobs Act (the "Act") into retained earnings. The guidance allows entities to reclassify from accumulated other comprehensive income to retained earnings stranded tax effects resulting from the Act's new federal corporate income tax rate. The guidance also allows entities to elect to reclassify other stranded tax effects that relate to the Act but do not directly relate to the change in the federal tax rate (e.g., state taxes, changing from a worldwide tax system to a territorial system). Tax effects that are stranded in accumulated other comprehensive income for other reasons (e.g., prior changes in tax law, a change in valuation allowance) may not be reclassified. The standard is effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within the fiscal year. Early adoption is permitted, including adoption in any interim period for which financial statements have not yet been issued. Entities have the option to apply the guidance retrospectively or in the period of adoption. The adoption of this standard is not expected to have a material impact on our consolidated financial statements. In March 2018, the FASB issued ASU 2018-05, “Income Taxes (ASC 740), Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118.” The ASU adds various SEC paragraphs pursuant to the issuance of the December 2017 SEC Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”), which was effective immediately. The SEC issued SAB 118 to address concerns about reporting entities’ ability to timely comply with the accounting requirements to recognize all of the effects of the Tax Cuts and Jobs Act in the period of enactment. SAB 118 allows disclosure that timely determination of some or all of the income tax effects from the Tax Cuts and Jobs Act are incomplete by the due date of the financial statements and if possible to provide a reasonable estimate. We have accounted for the tax effects of the Tax Cuts and Jobs Act under the guidance of SAB 118, on a provisional basis. Our accounting for certain income tax effects is incomplete, but we have determined reasonable estimates for those effects and have recorded provisional amounts in our condensed consolidated financial statements. Refer to Note 9, "Income Taxes," for further information.

EARNINGS PER SHARE (TWO-CLASS M

EARNINGS PER SHARE (TWO-CLASS METHOD)	9 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
EARNINGS PER SHARE (TWO-CLASS METHOD)	EARNINGS PER SHARE (TWO-CLASS METHOD) The following table sets forth the computation of basic and diluted earnings per share (in thousands, except per share data): Thirteen Week Periods Ended Thirty-Nine Week Periods Ended June 30, 2018 July 1, 2017 June 30, 2018 July 1, 2017 Numerator for earnings per share: Net income from continuing operations $ 217,391 $ 169,832 $ 731,242 $ 444,394 Less dividends paid on participating securities — — (56,148 ) (95,971 ) $ 217,391 $ 169,832 $ 675,094 $ 348,423 Net loss from discontinued operations (145 ) (779 ) (2,943 ) (965 ) Net income applicable to common stock - basic and diluted $ 217,246 $ 169,053 $ 672,151 $ 347,458 Denominator for basic and diluted earnings per share under the two-class method: Weighted average common shares outstanding 52,470 51,932 52,241 52,718 Vested options deemed participating securities 3,127 2,958 3,357 3,055 Total shares for basic and diluted earnings per share 55,597 54,890 55,598 55,773 Net earnings per share from continuing operations - basic and diluted $ 3.91 $ 3.09 $ 12.14 $ 6.25 Net loss per share from discontinued operations - basic and diluted — (0.01 ) (0.05 ) (0.02 ) Net earnings per share $ 3.91 $ 3.08 $ 12.09 $ 6.23

INVENTORIES

INVENTORIES	9 Months Ended
	Jun. 30, 2018
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES Inventories are stated at the lower of cost or market. Cost of inventories is generally determined by the average cost and the first-in, first-out (FIFO) methods and includes material, labor and overhead related to the manufacturing process. Inventories consist of the following (in thousands): June 30, 2018 September 30, 2017 Raw materials and purchased component parts $ 553,006 $ 496,899 Work-in-progress 220,883 187,009 Finished goods 139,395 131,548 Total 913,284 815,456 Reserves for excess and obsolete inventory (98,033 ) (84,775 ) Inventories - Net $ 815,251 $ 730,681

INTANGIBLE ASSETS

INTANGIBLE ASSETS	9 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS	INTANGIBLE ASSETS Other intangible assets - net in the condensed consolidated balance sheets consist of the following (in thousands): June 30, 2018 September 30, 2017 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Trademarks and trade names $ 746,859 $ — $ 746,859 $ 729,931 $ — $ 729,931 Technology 1,309,675 399,828 909,847 1,292,719 351,638 941,081 Order backlog 11,000 4,275 6,725 29,000 26,668 2,332 Other 73,226 21,583 51,643 63,599 19,081 44,518 Total $ 2,140,760 $ 425,686 $ 1,715,074 $ 2,115,249 $ 397,387 $ 1,717,862 Intangible assets acquired during the thirty-nine week period ended June 30, 2018 were as follows (in thousands): Gross Amount Amortization Period Intangible assets not subject to amortization: Goodwill $ 460,961 Trademarks and trade names 17,300 478,261 Intangible assets subject to amortization: Technology 20,600 20 years Order backlog 8,300 1 year Customer relationships 10,000 20 years 38,900 15.9 years Total $ 517,161 The aggregate amortization expense on identifiable intangible assets for the thirty-nine week period s ended June 30, 2018 and July 1, 2017 was approximately $53.8 million and $70.8 million , respectively. The estimated amortization expense is $73.2 million for fiscal year 2018 , $73.3 million for fiscal year 2019 , and $68.7 million for each of the four succeeding fiscal years 2020 through 2023 . The following is a summary of changes in the carrying value of goodwill by segment from September 30, 2017 through June 30, 2018 (in thousands): Power & Control Airframe Non- aviation Total Balance - September 30, 2017 $ 3,269,981 $ 2,382,082 $ 93,275 $ 5,745,338 Goodwill acquired during the year 460,707 254 — 460,961 Purchase price allocation adjustments 5,354 — — 5,354 Currency translation adjustment — (2,401 ) — (2,401 ) Other (192 ) 187 — (5 ) Balance - June 30, 2018 $ 3,735,850 $ 2,380,122 $ 93,275 $ 6,209,247

DEBT

DEBT	9 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
DEBT	DEBT The Company’s debt consists of the following (in thousands): June 30, 2018 Gross Amount Debt Issuance Costs Original Issue Discount or Premium Net Amount Short-term borrowings—trade receivable securitization facility $ 300,000 $ (44 ) $ — $ 299,956 Term loans $ 7,619,039 $ (73,105 ) $ (21,984 ) $ 7,523,950 5.50% senior subordinated notes due 2020 (2020 Notes) 550,000 (2,451 ) — 547,549 6.00% senior subordinated notes due 2022 (2022 Notes) 1,150,000 (5,861 ) — 1,144,139 6.50% senior subordinated notes due 2024 (2024 Notes) 1,200,000 (7,160 ) — 1,192,840 6.50% senior subordinated notes due 2025 (2025 Notes) 750,000 (3,637 ) 3,772 750,135 6.375% senior subordinated notes due 2026 (6.375% 2026 Notes) 950,000 (8,050 ) — 941,950 6.875% senior subordinated notes due 2026 (6.875% 2026 Notes) 500,000 (5,038 ) (3,722 ) 491,240 12,719,039 (105,302 ) (21,934 ) 12,591,803 Less current portion 76,427 (634 ) — 75,793 Long-term debt $ 12,642,612 $ (104,668 ) $ (21,934 ) $ 12,516,010 September 30, 2017 Gross Amount Debt Issuance Costs Original Issue Discount or Premium Net Amount Short-term borrowings—trade receivable securitization facility $ 300,000 $ (413 ) $ — $ 299,587 Term loans $ 6,973,009 $ (64,104 ) $ (18,948 ) $ 6,889,957 5.50% 2020 Notes 550,000 (3,243 ) — 546,757 6.00% 2022 Notes 1,150,000 (6,941 ) — 1,143,059 6.50% 2024 Notes 1,200,000 (8,042 ) — 1,191,958 6.50% 2025 Notes 750,000 (4,033 ) 4,182 750,149 6.375% 2026 Notes 950,000 (8,806 ) — 941,194 11,573,009 (95,169 ) (14,766 ) 11,463,074 Less current portion 70,031 (577 ) — 69,454 Long-term debt $ 11,502,978 $ (94,592 ) $ (14,766 ) $ 11,393,620 Accrued interest was $88.9 million and $82.2 million as of June 30, 2018 and September 30, 2017 , respectively. Amendment No. 4 to the Second Amended and Restated Credit Agreement - On November 30, 2017, the Company entered into Amendment No. 4 to the Second Amended and Restated Credit Agreement. Pursuant to Amendment No. 4, TransDigm, among other things, incurred new tranche E term loans and new Tranche F term loans in aggregate principal amounts equal to $1,503 million and $2,857 million , respectively, and repaid in full all of the existing tranche E term loans and Tranche F term loans outstanding under the Second and Amended Restated Credit Agreement immediately prior to the refinancing facility agreement. Additionally, pursuant to Amendment No. 4, TransDigm converted approximately $798 million of existing tranche D term loans into additional tranche F term loans. The refinancing facility agreement also decreased the margin applicable to the existing tranche E term loans and tranche F term loans to LIBO rate plus 2.75% per annum. The terms and conditions (other than maturity date and pricing) that apply to the tranche E and tranche F term loans are substantially the same as the terms and conditions that apply to the tranche D term loans immediately prior to Amendment No. 4. In addition to the incremental discount of $1.0 million recorded for the tranche F term loans, the Company capitalized $2.9 million and expensed $0.7 million of refinancing costs representing debt issuance costs associated with Amendment No. 4 during the thirty-nine week period ended June 30, 2018 . The Company also wrote off $0.5 million in unamortized debt issuance costs related to the tranche D term loans that were converted to tranche F term loans and wrote off $0.2 million in unamortized debt issuance costs related to the tranche F terms loans. Refinancing Facility Agreement to the Second Amended and Restated Credit Agreement - On February 22, 2018, the Company entered into a refinancing facility agreement. TransDigm, among other things, incurred new tranche G term loans in an aggregate principal amount equal to $1,809 million and repaid in full all of the existing tranche G term loans outstanding under the Second and Amended Restated Credit Agreement immediately prior to the refinancing facility agreement. The refinancing facility agreement also decreased the margin applicable to the tranche G term loans to LIBO rate plus 2.5% per annum. The terms and conditions that apply to the tranche G term loans other than pricing are substantially the same as the terms and conditions that apply to the tranche G term loans immediately prior to the refinancing facility agreement. The Company capitalized $0.5 million and expensed $0.3 million of refinancing costs representing debt issuance costs associated with the refinancing facility agreement during the thirty-nine week period ended June 30, 2018 . Additionally, the Company wrote off $0.2 million in unamortized debt issuance costs related to the tranche G terms loans. Issuance of Senior Subordinated Notes – On May 8, 2018, TransDigm UK Holdings plc, a wholly-owned, indirect subsidiary of TD Group, issued $500 million in aggregate principal amount of new 6.875% 2026 Notes at an issue price of 99.24% of the principal amount. The 6.875% 2026 Notes bear interest at the rate of 6.875% per annum, which accrues from May 8, 2018 and is payable semiannually in arrears on May 15 and November 15 of each year, commencing on November 15, 2018. The 6.875% 2026 Notes mature on May 15, 2026, unless earlier redeemed or repurchased, and are subject to the terms and conditions set forth in the Indenture governing these 6.875% 2026 Notes. The 6.875% 2026 Notes are subordinated to all of the Company's existing and future senior debt, rank equally with all of its existing and future senior subordinated debt and rank senior to all of its future debt that is expressly subordinated to the 6.875% 2026 Notes. The 6.875% 2026 Notes are guaranteed on a senior subordinated unsecured basis by TransDigm Inc., TD Group and TransDigm Inc.'s Domestic Restricted Subsidiaries, as defined in the applicable indenture. The guarantees of the 6.875% 2026 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 6.875% 2026 Notes. The 6.875% 2026 Notes are structurally subordinated to all of the liabilities of TD Group’s non-guarantor subsidiaries. The 6.875% 2026 Notes Indenture contains certain covenants that, among other things, limit the incurrence of additional indebtedness, the payment of dividends, transactions with affiliates, asset sales, acquisitions, mergers, and consolidations, liens and encumbrances, and prepayments of certain other indebtedness. The 6.875% 2026 Notes Indenture contains events of default customary for agreements of their type (with customary grace periods, as applicable) and provide that, upon the occurrence of an event of default arising from certain events of bankruptcy or insolvency, all outstanding 6.875% 2026 Notes will become due and payable immediately without further action or notice. If any other type of event of default occurs and is continuing, then the trustee or the holders of at least 25% in principal amount of the outstanding 6.875% 2026 Notes may declare all such notes to be due and payable immediately. In addition to the discount of $3.8 million recorded upon the issuance of these 6.875% 2026 Notes, the Company capitalized $5.1 million and expensed $0.6 million of refinancing costs associated with the issuance of the 6.875% 2026 Notes during the thirty-nine week period ended June 30, 2018 . Amendment No. 5 to the Second Amended and Restated Credit Agreement - On May 30, 2018, the Company entered into Amendment No. 5 to the Second Amended and Restated Credit Agreement. The Company capitalized $7.2 million of refinancing costs representing fees associated with the execution of Amendment No. 5 during the thirty-nine week period ended June 30, 2018 . Pursuant to Amendment No. 5, the Company, among other things, incurred new tranche E term loans in an aggregate principal amount equal to $1,322 million , and repaid in full all of the existing tranche E term loans outstanding under the Second Amended and Restated Credit Agreement immediately prior to Amendment No. 5. The Company also incurred incremental tranche E term loans in an aggregate principal amount equal to $933 million . The new tranche E term loans and incremental tranche E term loans mature on May 30, 2025. Amendment No. 5 also decreased the margin applicable to the new tranche E term loans to LIBO rate plus 2.5% per annum. The terms and conditions that apply to the tranche E term loans, other than the maturity date and margin, are substantially the same as the terms and conditions that apply to the tranche E term loans immediately prior to Amendment No. 5. In addition to the discount of $4.7 million recorded for the tranche E term loans, the Company capitalized $7.0 million and expensed $2.6 million of refinancing costs representing debt issuance costs associated with Term Loan E during the thirty-nine week period ended June 30, 2018 . The Company also wrote off $0.3 million in unamortized debt issuance costs related to the tranche E terms loans. Additionally, pursuant to Amendment No. 5, the Company incurred new tranche F term loans in an aggregate principal amount equal to $3,578 million , and repaid in full all of the existing tranche F term loans outstanding under the Second and Amended Restated Credit Agreement immediately prior to Amendment No. 5. Amendment No. 5 also decreased the margin applicable to the tranche F term loans to LIBO rate plus 2.5% per annum. The Company capitalized $2.0 million of refinancing costs representing debt issuance costs associated with the tranche F term loans during the thirty-nine week period ended June 30, 2018 . Additionally, the Company wrote off $0.3 million in unamortized debt issuance costs related to the tranche F term loans. Finally, under the terms of Amendment No. 5, the maturity date of our $600 million revolving credit facility was extended to December 28, 2022. The terms and conditions that apply to the revolving credit facility, other than the maturity date, are substantially the same as the terms and conditions that applied to the revolving credit facility immediately prior to Amendment No. 5. At June 30, 2018 , the Company had $14.6 million in letters of credit outstanding and $585.4 million of borrowings available under the revolving commitments. During the thirty-nine week period ended June 30, 2018 , the Company capitalized $0.4 million and expensed $0.2 million representing debt issuance costs expensed in conjunction with the refinancing of the revolving credit facility.

INCOME TAXES

INCOME TAXES	9 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Tax Cuts and Jobs Act (the "Act") was enacted on December 22, 2017. The Act reduces the U.S. federal corporate tax rate from 35% to 21% , requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and creates new taxes on certain foreign-sourced earnings. The rate change is administratively effective at the beginning of our fiscal year (October 1, 2017), using a blended rate for the annual period. As a result, the blended statutory tax rate for the year is 24.5% . At June 30, 2018 , we had not completed our accounting for the tax effects of enactment of the Act; however, in certain cases, we have made a reasonable estimate of the effects on our existing deferred tax balances and the one-time transition tax in accordance with the SEC's amendment to SAB 118. We have recognized a provisional benefit amount of $170.2 million related to the remeasurement of our deferred tax balance for the thirty-nine week period ended June 30, 2018. However, we are still analyzing certain aspects of the Act and refining our calculations, which could potentially affect the measurement of these balances or potentially give rise to new deferred tax amounts. In addition, we have recognized a provisional expense amount of $23.1 million for our one-time transition tax liability for the thirty-nine week period ended June 30, 2018 . The one-time transition tax is based on our total post-1986 earnings and profits ("E&P") that we previously deferred from U.S. income taxes and is based in part on the amount of those earnings held in cash and other specified assets. However, we continue to refine the calculation of the total post-1986 E&P for our foreign subsidiaries. This amount may change when we finalize the calculation of post-1986 foreign E&P previously deferred from US federal taxation and finalize the amounts held in cash or other specified assets. As a result of the Act, we recognized a net provisional benefit amount of $147.1 million as a discrete tax benefit, which is included as a component of income tax expense from continuing operations for the thirty-nine week period ended June 30, 2018 . At the end of each reporting period, TD Group makes an estimate of its annual effective income tax rate. The estimate used in the year-to-date period may change in subsequent periods. During the thirteen week periods ended June 30, 2018 and July 1, 2017 , the effective income tax rate was 18.1% and 28.0% , respectively. During the thirty-nine week period s ended June 30, 2018 and July 1, 2017 , the effective income tax rate was (3.9)% and 24.7% , respectively. The Company's lower effective tax rate for the thirteen week period ended June 30, 2018 was primarily due to the reduction in the U.S. federal corporate statutory rate related to the enactment of the Act. The Company’s lower effective tax rate for the thirty-nine week period ended June 30, 2018 was primarily due to the reduction in the U.S. federal corporate tax rate as well as discrete adjustments related to the enactment of the Act described above. The Company’s effective tax rate for the thirteen and thirty-nine week periods ended June 30, 2018 was lower than the Federal statutory tax rate primarily due to the enactment of the Act described above. The Company’s effective tax rate for the thirteen and thirty-nine week periods ended July 1, 2017 was lower than the Federal statutory tax rate primarily due to excess tax benefits from share based payments, the domestic manufacturing deduction and foreign earnings taxed at rates lower than the U.S. statutory rate. The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction, various state and local jurisdictions as well as foreign jurisdictions located in Belgium, Canada, China, France, Germany, Hong Kong, Hungary, Japan, Malaysia, Mexico, Norway, Singapore, Sri Lanka, Sweden and the United Kingdom. The Company is no longer subject to U.S. federal examinations for years before fiscal 2014. The Company is currently under U.S. federal examination for fiscal 2014. In addition, the Company is subject to state income tax examinations for fiscal years 2009 and later. At June 30, 2018 and September 30, 2017 , TD Group had $10.3 million and $8.7 million in unrecognized tax benefits, the recognition of which would have an effect of approximately $10.2 million on the effective tax rate at June 30, 2018 and $8.7 million on the effective tax rate at September 30, 2017 . The Company believes the tax positions that comprise the unrecognized tax benefits will be reduced by approximately $1.6 million over the next 12 months. The Company recognizes accrued interest and penalties related to unrecognized tax benefits in income tax expense.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	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 thousands): June 30, 2018 September 30, 2017 Level Carrying Amount Fair Value Carrying Amount Fair Value Assets: Cash and cash equivalents 1 $ 1,853,373 $ 1,853,373 $ 650,561 $ 650,561 Interest rate cap agreements (1) 2 31,948 31,948 12,904 12,904 Interest rate swap agreements (2) 2 5,458 5,458 — — Interest rate swap agreements (1) 2 40,919 40,919 2,905 2,905 Liabilities: Interest rate swap agreements (3) 2 1,554 1,554 20,740 20,740 Interest rate swap agreements (4) 2 4,153 4,153 9,731 9,731 Short-term borrowings - trade receivable securitization facility (5) 1 299,956 299,956 299,587 299,587 Long-term debt, including current portion: Term loans (5) 2 7,523,950 7,536,675 6,889,957 6,965,628 5.50% 2020 Notes (5) 1 547,549 548,625 546,757 558,250 6.00% 2022 Notes (5) 1 1,144,139 1,155,750 1,143,059 1,178,750 6.50% 2024 Notes (5) 1 1,192,840 1,215,000 1,191,958 1,236,000 6.50% 2025 Notes (5) 1 750,135 757,500 750,149 776,807 6.375% 2026 Notes (5) 1 941,950 942,875 941,194 971,375 6.875% 2026 Notes (5) 1 491,240 506,250 — — (1) Included in other non-current assets on the condensed consolidated balance sheet. (2) Included in prepaid expenses and other on the condensed consolidated balance sheet. (3) Included in accrued liabilities on the condensed consolidated balance sheet. (4) Included in other non-current liabilities on the condensed consolidated balance sheet. (5) The carrying amount of the debt instrument is presented net of debt issuance costs, premium and discount. Refer to Note 8, "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 using unobservable inputs. Interest rate swaps were measured at fair value using quoted market prices for the swap interest rate indexes over the term of the swap discounted to present value versus the fixed rate of the contract. The interest rate caps were measured at fair value using implied volatility rates of each individual caplet and the yield curve for the related periods. The estimated fair value of the Company’s term loans was based on information provided by the agent under the Company’s senior secured credit facility. The estimated fair values of the Company’s notes were based upon quoted market prices. 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 impact to the fair value of derivative assets based on the Company's evaluation of counterparties' credit risks. The fair value of cash and cash equivalents, trade accounts receivable-net and accounts payable approximated book value due to the short-term nature of these instruments at June 30, 2018 and September 30, 2017 .

DERIVATIVES AND HEDGING ACTIVIT

DERIVATIVES AND HEDGING ACTIVITIES	9 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES AND HEDGING ACTIVITIES	DERIVATIVES AND HEDGING ACTIVITIES The Company is exposed to, among other things, the impact of changes in 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. The Company has agreements with each of its swap and cap counterparties that contain a provision whereby if the Company defaults on the credit facility the Company could also be declared in default on its swaps and caps, resulting in an acceleration of payment under the swaps and caps. Interest rate swap and cap agreements are used to manage interest rate risk associated with floating-rate borrowings under our credit facility. The interest rate swap and cap 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 through the expiration date of the interest rate swap and cap agreements, thereby reducing the impact of interest rate changes on future interest expense. 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. These derivative instruments qualify as effective cash flow hedges under GAAP. For these cash flow hedges, the effective portion of the gain or loss from the financial instruments was 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 affected earnings. As the interest rate swap and cap 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 condensed consolidated statements of income. The following table summarizes the Company's interest rate swap agreements: Aggregate Notional Amount (in millions) Start Date End Date Related Term Loans Conversion of Related Variable Rate Debt to Fixed Rate of: $750 3/31/2016 6/30/2020 Tranche E 5.3% (2.8% plus the 2.5% margin percentage) $500 6/29/2018 3/31/2025 Tranche E 5.5% (3.0% plus the 2.5% margin percentage) $750 6/30/2020 6/30/2022 Tranche E 5.0% (2.5% plus the 2.5% margin percentage) $1,500 6/30/2022 3/31/2025 Tranche E 5.6% (3.1% plus the 2.5% margin percentage) $1,000 9/30/2014 6/28/2019 Tranche F 4.9% (2.4% plus the 2.5% margin percentage) $1,000 6/28/2019 6/30/2021 Tranche F 4.3% (1.8% plus the 2.5% margin percentage) $1,400 6/30/2021 3/31/2023 Tranche F 5.5% (3.0% plus the 2.5% margin percentage) $500 12/30/2016 12/30/2021 Tranche G 4.4% (1.9% plus the 2.5% margin percentage) $400 9/30/2017 9/30/2022 Tranche G 4.4% (1.9% plus the 2.5% margin percentage) $900 12/31/2021 6/28/2024 Tranche G 5.6% (3.1% plus the 2.5% margin percentage) $400 9/30/2022 6/28/2024 Tranche G 5.5% (3.0% plus the 2.5% margin percentage) The following table summarizes the Company's interest rate cap agreements: Aggregate Notional Amount Start Date End Date Related Term Loans Offsets Variable Rate Debt Attributable to Fluctuations Above: $750 9/30/2015 6/30/2020 Tranche E Three month LIBO rate of 2.5% $750 6/30/2020 6/30/2022 Tranche E Three month LIBO rate of 2.5% $400 6/30/2016 6/30/2021 Tranche F Three month LIBO rate of 2.0% $400 12/30/2016 12/30/2021 Tranche G Three month LIBO rate of 2.5% All interest rate swap and cap agreements are recognized in our condensed consolidated balance sheets at fair value. 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 long-term asset or liability. The amounts shown in the table below represent the gross amounts of recognized assets and liabilities, the amounts offset in the condensed consolidated balance sheet and the net amounts of assets and liabilities presented therein. June 30, 2018 September 30, 2017 Asset Liability Asset Liability Interest rate cap agreements $ 31,948 $ — $ 12,904 $ — Interest rate swap agreements 57,945 (17,275 ) 9,235 (36,801 ) Total 89,893 (17,275 ) 22,139 (36,801 ) Effect of counterparty netting (11,568 ) 11,568 (6,330 ) 6,330 Net derivatives as classified in the balance sheet (1) $ 78,325 $ (5,707 ) $ 15,809 $ (30,471 ) (1) Refer to Note 10, "Fair Value Measurements," for the condensed consolidated balance sheet classification of our interest rate swap and cap agreements. Based on the fair value amounts of the interest rate swap and cap agreements determined as of June 30, 2018 , the estimated net amount of existing gains and losses and caplet amortization expected to be reclassified into interest income within the next twelve months is approximately $0.4 million . Effective September 30, 2016, the Company redesignated the interest rate cap agreements related to the $400 million and the $750 million aggregate notional amount with cap rates of 2.0% and 2.5% , respectively, based on the expected probable cash flows associated with the 2016 term loans and 2015 term loans in consideration of the Company’s ability to select one-month, two-month, three-month, or six-month LIBO rate set forth in the Second Amended and Restated Credit Agreement. Accordingly, amounts previously recorded as a component of accumulated other comprehensive loss in stockholder’s deficit amortized into interest expense was $3.0 million and $2.9 million for the thirty-nine week period s ended June 30, 2018 and July 1, 2017, respectively. The accumulated other comprehensive loss to be reclassified into interest expense over the remaining term of the cap agreements is $7.9 million with a related tax benefit of $2.2 million as of June 30, 2018 . Effective December 30, 2017, the Company redesignated the existing interest rate swap agreements related to the $750 million , $500 million , $1,000 million and $750 million aggregate notional amounts with swap rates of 5.00% , 4.40% , 4.30% and 5.30% , respectively, based on the expected probable cash flows associated with certain term loans in consideration of the Company’s removal of the LIBO rate floor on the certain term loans as set forth in Amendment No. 4 to the Second Amended and Restated Credit Agreement. Accordingly, the amount recorded as a component of accumulated other comprehensive loss in stockholders’ deficit related to these redesignated interest rate swap hedges will be amortized into earnings based on the original maturity date of the related interest rate swap agreements. Amounts previously recorded as a component of accumulated other comprehensive loss in stockholder’s deficit amortized into interest expense was $0.5 million for the thirty-nine week period ended June 30, 2018 . The accumulated other comprehensive gain to be reclassified into interest expense over the remaining term of the swap agreements is immaterial. Effective March 31, 2018, the Company redesignated the existing interest rate swap agreements related to the $1,000 million and the $400 million aggregate notional amount with swap rates of 4.90% and 4.40% , respectively, based on the expected probable cash flows associated with certain term loans in consideration of the Company’s removal of the LIBO rate floor on the certain term loans as set forth in the refinancing facility agreement dated February 22, 2018 related to the Second Amended and Restated Credit Agreement. Accordingly, the amount recorded as a component of accumulated other comprehensive loss in stockholders’ deficit related to these redesignated interest rate swap hedges will be amortized into earnings based on the original maturity date of the related interest rate swap agreements. Amounts previously recorded as a component of accumulated other comprehensive loss in stockholder’s deficit amortized into interest income was $0.7 million for the thirty-nine week period ended June 30, 2018 . The accumulated other comprehensive gain to be reclassified into interest income over the remaining term of the swaps agreements is $12.1 million with a related tax expense of $2.9 million as of June 30, 2018.

SEGMENTS

SEGMENTS	9 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
SEGMENTS	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/electro-mechanical actuators and controls, ignition systems and engine technology, specialized pumps and valves, power conditioning devices, specialized AC/DC electric motors and generators, databus and power controls, high performance hoists, winches and lifting devices and cargo loading and handling systems. 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, rods and locking devices, engineered connectors and elastomers, cockpit security components and systems, aircraft audio systems, specialized lavatory components, seat belts and safety restraints, engineered interior surfaces and related components, lighting and control technology, military personnel parachutes and cargo delivery systems. 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/electro-mechanical actuators and controls for space applications, 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 primary measurement used by management to review and assess the operating performance of each segment is EBITDA As Defined. The Company defines EBITDA As Defined as earnings before interest, taxes, depreciation and amortization plus certain non-operating items recorded as corporate expenses including refinancing costs, acquisition-related costs, transaction-related costs and non-cash compensation charges incurred in connection with the Company’s stock option plans. Acquisition-related costs represent accounting adjustments to inventory associated with acquisitions of businesses and product lines that were charged to cost of sales when the inventory was sold; costs incurred to integrate acquired businesses and product lines into the Company’s operations, facility relocation costs and other acquisition-related costs; transaction related costs comprising deal fees; legal, financial and tax diligence expenses and valuation costs that are required to be expensed as incurred and other acquisition accounting adjustments. EBITDA As Defined is not a measurement of financial performance under 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 GAAP. The Company’s segments are reported on the same basis used internally for evaluating performance and for allocating resources. The accounting policies for each segment are the same as those described in the summary of significant accounting policies in 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 insignificant for the periods presented below. Certain corporate-level expenses are allocated to the operating segments. Effective October 1, 2017, the Company made an organizational realignment of certain businesses comprising the Power & Control, Airframe and the Non-Aviation segments. Operating results for the thirteen and thirty-nine week period s ended July 1, 2017 and total assets as of September 30, 2017 were reclassified to conform to the presentation for the thirteen and thirty-nine week period s ended June 30, 2018 . The following table presents net sales by reportable segment (in thousands): Thirteen Week Periods Ended Thirty-Nine Week Periods Ended June 30, 2018 July 1, 2017 June 30, 2018 July 1, 2017 Net sales to external customers Power & Control $ 546,905 $ 499,069 $ 1,558,083 $ 1,408,853 Airframe 398,596 362,871 1,101,771 1,072,044 Non-aviation 35,161 35,715 101,838 99,504 $ 980,662 $ 897,655 $ 2,761,692 $ 2,580,401 The following table reconciles EBITDA As Defined by segment to consolidated income from continuing operations before income taxes (in thousands): Thirteen Week Periods Ended Thirty-Nine Week Periods Ended June 30, 2018 July 1, 2017 June 30, 2018 July 1, 2017 EBITDA As Defined Power & Control $ 288,202 $ 262,855 $ 808,539 $ 708,601 Airframe 196,746 184,091 541,171 535,600 Non-aviation 11,075 11,908 30,392 32,576 Total segment EBITDA As Defined 496,023 458,854 1,380,102 1,276,777 Unallocated corporate expenses 8,882 11,266 28,305 26,319 Total Company EBITDA As Defined 487,141 447,588 1,351,797 1,250,458 Depreciation and amortization expense 33,925 36,367 95,534 109,076 Interest expense - net 167,577 152,141 489,776 445,986 Acquisition-related costs 10,381 4,484 16,940 30,804 Stock compensation expense 13,708 11,580 36,411 32,707 Refinancing costs 4,159 345 5,910 35,936 Other, net (8,150 ) 6,824 3,534 5,982 Income from continuing operations before income taxes $ 265,541 $ 235,847 $ 703,692 $ 589,967 The following table presents total assets by segment (in thousands): June 30, 2018 September 30, 2017 Total assets Power & Control $ 5,712,597 $ 5,135,459 Airframe 3,977,451 3,923,172 Non-aviation 227,905 224,936 Corporate 1,886,524 614,594 Assets of discontinued operations — 77,500 $ 11,804,477 $ 9,975,661 The Company’s sales principally originate from the United States, and the Company’s long-lived assets are principally located in the United States.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE LOSS	9 Months Ended
	Jun. 30, 2018
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE LOSS	ACCUMULATED OTHER COMPREHENSIVE LOSS The following table presents the components of accumulated other comprehensive loss, net of taxes, for the thirty-nine week period ended June 30, 2018 (in thousands): Unrealized (loss) gain on derivatives designated and qualifying as cash flow hedges (1) Defined benefit pension plan activity Currency translation adjustment Total Balance at September 30, 2017 $ (26,669 ) $ (16,365 ) $ (42,109 ) $ (85,143 ) Current-period other comprehensive gain (loss) 63,742 — (4,355 ) 59,387 Amounts reclassified from AOCI related to interest rate swap and cap agreements 2,039 — — 2,039 Balance at June 30, 2018 $ 39,112 $ (16,365 ) $ (46,464 ) $ (23,717 ) (1) Unrealized (loss) gain represents interest rate swap and cap agreements, net of taxes of $(954) and $5,002 for the thirteen week periods ended June 30, 2018 and July 1, 2017 and $(25,679) and $(19,425) for the thirty-nine week period s ended June 30, 2018 and July 1, 2017 , respectively. A summary of reclassifications out of accumulated other comprehensive loss for the thirty-nine week period s ended June 30, 2018 and July 1, 2017 is provided below (in thousands): Amount reclassified Thirty-Nine Week Periods Ended Description of reclassifications out of accumulated other comprehensive loss June 30, 2018 July 1, 2017 Amortization from redesignated interest rate swap and cap agreements (1) $ 2,816 $ 2,870 Deferred tax benefit from redesignated interest rate swap and cap agreements (777 ) (1,072 ) Losses reclassified into earnings, net of tax $ 2,039 $ 1,798 (1) This component of accumulated other comprehensive loss is included in interest expense (see Note 11, “Derivatives and Hedging Activities,” for additional information).

DISCONTINUED OPERATIONS

DISCONTINUED OPERATIONS	9 Months Ended
	Jun. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	DISCONTINUED OPERATIONS In connection with the settlement of a Department of Justice investigation into the competitive effects of the acquisition, during the fourth quarter of 2017, the Company committed to dispose of the Schroth business. Therefore, Schroth was classified as held-for-sale in the fourth quarter of 2017. The results of operations of Schroth are reflected as discontinued operations in the accompanying consolidated financial statements for all periods presented. On January 26, 2018, the Company completed the sale of Schroth in a management buyout to a private equity fund and certain members of Schroth management for approximately $61.4 million , which includes a working capital adjustment of $0.3 million that was settled on July 6, 2018. The Company previously acquired Schroth in February 2017 (refer to Note 3, “Acquisitions and Divestitures”). The loss from discontinued operations was $0.1 million and $2.9 million in the condensed consolidated statements of income for the thirteen and thirty-nine week periods ended June 30, 2018 . The loss from discontinued operations was $0.8 million and $1.0 million in the condensed consolidated statements of income for the thirteen and thirty-nine week periods ended July 1, 2017. Previously, in the fourth quarter of fiscal 2017, we recorded a $32.0 million impairment charge to write down the Schroth assets to fair value. The impairment charge was based on an internal assessment of the recovery of Schroth’s assets. The following is the summarized operating results for Schroth for the thirteen and thirty-nine week periods ended June 30, 2018 and July 1, 2017 (in thousands): Thirteen Week Period Ended Thirty-Nine Week Period Ended June 30, 2018 July 1, 2017 June 30, 2018 July 1, 2017 Net sales $ — $ 10,012 $ 11,808 $ 14,516 (Loss) Income from discontinued operations before income taxes — (779 ) 354 (965 ) Income tax benefit — — 2,016 — (Loss) Income from discontinued operations, net of tax — (779 ) 2,370 (965 ) Net loss on sale of discontinued operations, net of tax (145 ) — (5,313 ) — Loss from discontinued operations $ (145 ) $ (779 ) $ (2,943 ) $ (965 )

SUBSEQUENT EVENTS (Notes)

SUBSEQUENT EVENTS (Notes)	9 Months Ended
	Jun. 30, 2018
Subsequent Event [Line Items]
Subsequent Events [Text Block]	SUBSEQUENT EVENTS On July 13, 2018, the Company acquired all of the outstanding stock of Skandia Inc. ("Skandia") for a total purchase price of approximately $84 million , including the assumption of debt and subject to purchase price adjustments. The Company financed the acquisition with cash on hand. Skandia provides highly engineered seating foam, foam fabrication, flammability testing and acoustic solutions for the business jet market. Skandia will be included in TransDigm's Airframe segment. The Company expects that no goodwill recognized for the acquisition will be deductible for tax purposes. On July 31, 2018, the Company amended the trade receivable securitization facility to extend the maturity date to July 31, 2019. In connection with the Company's amendment of the trade receivable securitization facility, the Company increased the borrowing capacity from $300 million to $350 million . As of June 30, 2018, the Company has borrowed $300 million under the trade receivable securitization facility.

SUPPLEMENTAL GUARANTOR INFORMAT

SUPPLEMENTAL GUARANTOR INFORMATION	9 Months Ended
	Jun. 30, 2018
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
SUPPLEMENTAL GUARANTOR INFORMATION	SUPPLEMENTAL GUARANTOR INFORMATION TransDigm Inc.’s 2020 Notes, 2022 Notes, 2024 Notes, 2025 Notes and 6.375% 2026 Notes are jointly and severally guaranteed, on a senior subordinated basis, by TD Group, TransDigm UK Holdings plc ("TransDigm UK") and TransDigm Inc.’s Domestic Restricted Subsidiaries, as defined in the applicable Indentures. TransDigm UK's 6.875% 2026 Notes are jointly and severally guaranteed, on a senior subordinated basis, by TD Group, TransDigm Inc. and TransDigm Inc.'s Domestic Restricted Subsidiaries as defined in the applicable indenture. The following supplemental condensed consolidating financial information presents, in separate columns, the balance sheets of the Company as of June 30, 2018 and September 30, 2017 and its statements of income and comprehensive income and cash flows for the thirty-nine week period s ended June 30, 2018 and July 1, 2017 for (i) TransDigm Group on a parent only basis with its investment in subsidiaries recorded under the equity method, (ii) TransDigm Inc. including its directly owned operations and non-operating entities, excluding TransDigm UK, (iii) TransDigm UK (iv) the Subsidiary Guarantors (other than TransDigm UK) on a combined basis, (v) Non-Guarantor Subsidiaries and (vi) the Company on a consolidated basis. Separate financial statements of TransDigm Inc. are not presented because TransDigm Inc.’s 2020 Notes, 2022 Notes, 2024 Notes, 2025 Notes and 6.375% 2026 Notes are fully and unconditionally guaranteed on a senior subordinated basis by TD Group, TransDigm UK and all of TransDigm Inc's Domestic Restricted Subsidiaries and because TD Group has no significant operations or assets separate from its investment in TransDigm Inc. Separate financial statements of TransDigm UK are not presented because TransDigm UK's 6.875% 2026 Notes, issued in May 2018, are fully and unconditionally guaranteed on a senior subordinated basis by TD Group, TransDigm Inc. and all of TransDigm Inc.'s Domestic Restricted Subsidiaries. TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING BALANCE SHEET AS OF JUNE 30, 2018 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated ASSETS CURRENT ASSETS: Cash and cash equivalents $ 924 $ 1,628,948 $ 150 $ 25 $ 223,326 $ — $ 1,853,373 Trade accounts receivable - Net — — — 22,003 648,401 (12,236 ) 658,168 Inventories - Net — 47,309 — 653,972 117,027 (3,057 ) 815,251 Prepaid expenses and other — 26,406 — 21,188 11,016 — 58,610 Total current assets 924 1,702,663 150 697,188 999,770 (15,293 ) 3,385,402 INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES (2,099,404 ) 10,325,919 1,096,125 8,600,056 2,177,711 (20,100,407 ) — PROPERTY, PLANT AND EQUIPMENT - NET — 15,585 — 314,510 50,380 — 380,475 GOODWILL — 128,764 — 5,419,486 660,997 — 6,209,247 OTHER INTANGIBLE ASSETS - NET — 16,583 — 1,453,885 244,606 — 1,715,074 OTHER — 79,366 — 29,159 5,754 — 114,279 TOTAL ASSETS $ (2,098,480 ) $ 12,268,880 $ 1,096,275 $ 16,514,284 $ 4,139,218 $ (20,115,700 ) $ 11,804,477 LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY CURRENT LIABILITIES: Current portion of long-term debt $ — $ 75,793 $ — $ — $ — $ — $ 75,793 Short-term borrowings - trade receivable securitization facility — — — — 299,956 — 299,956 Accounts payable — 15,974 — 115,763 36,550 (12,350 ) 155,937 Accrued liabilities — 109,607 4,679 124,531 46,667 — 285,484 Total current liabilities — 201,374 4,679 240,294 383,173 (12,350 ) 817,170 LONG-TERM DEBT — 12,024,770 491,240 — — — 12,516,010 DEFERRED INCOME TAXES — 299,043 — 100 58,537 — 357,680 OTHER NON-CURRENT LIABILITIES — 110,255 — 74,904 26,938 — 212,097 Total liabilities — 12,635,442 495,919 315,298 468,648 (12,350 ) 13,902,957 STOCKHOLDERS’ (DEFICIT) EQUITY (2,098,480 ) (366,562 ) 600,356 16,198,986 3,670,570 (20,103,350 ) (2,098,480 ) TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY $ (2,098,480 ) $ 12,268,880 $ 1,096,275 $ 16,514,284 $ 4,139,218 $ (20,115,700 ) $ 11,804,477 TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING BALANCE SHEET AS OF SEPTEMBER 30, 2017 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated ASSETS CURRENT ASSETS: Cash and cash equivalents $ 2,416 $ 439,473 $ — $ (203 ) $ 208,875 $ — $ 650,561 Trade accounts receivable - Net — — — 25,069 652,807 (41,749 ) 636,127 Inventories - Net — 47,051 — 571,712 114,018 (2,100 ) 730,681 Assets held-for-sale — — — 6,428 71,072 — 77,500 Prepaid expenses and other — 4,746 — 24,141 9,796 — 38,683 Total current assets 2,416 491,270 — 627,147 1,056,568 (43,849 ) 2,133,552 INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES (2,953,620 ) 10,263,999 — 7,599,210 966,675 (15,876,264 ) — PROPERTY, PLANT AND EQUIPMENT - NET — 16,032 — 261,434 47,458 — 324,924 GOODWILL — 85,905 — 4,996,034 663,399 — 5,745,338 OTHER INTANGIBLE ASSETS - NET — 27,620 — 1,438,006 252,236 — 1,717,862 OTHER — 20,316 — 27,567 6,102 — 53,985 TOTAL ASSETS $ (2,951,204 ) $ 10,905,142 $ — $ 14,949,398 $ 2,992,438 $ (15,920,113 ) $ 9,975,661 LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY CURRENT LIABILITIES: Current portion of long-term debt $ — $ 69,454 $ — $ — $ — $ — $ 69,454 Short-term borrowings - trade receivable securitization facility — — — — 299,587 — 299,587 Accounts payable — 14,712 — 137,948 37,667 (41,566 ) 148,761 Accrued liabilities — 180,916 — 103,902 51,070 — 335,888 Liabilities held-for-sale — — — — 17,304 — 17,304 Total current liabilities — 265,082 — 241,850 405,628 (41,566 ) 870,994 LONG-TERM DEBT — 11,393,620 — — — — 11,393,620 DEFERRED INCOME TAXES — 442,415 — (99 ) 58,633 — 500,949 OTHER NON-CURRENT LIABILITIES — 61,347 — 73,245 26,710 — 161,302 Total liabilities — 12,162,464 — 314,996 490,971 (41,566 ) 12,926,865 STOCKHOLDERS’ (DEFICIT) EQUITY (2,951,204 ) (1,257,322 ) — 14,634,402 2,501,467 (15,878,547 ) (2,951,204 ) TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY $ (2,951,204 ) $ 10,905,142 $ — $ 14,949,398 $ 2,992,438 $ (15,920,113 ) $ 9,975,661 TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING STATEMENT OF INCOME AND COMPREHENSIVE INCOME FOR THE THIRTY-NINE WEEK PERIOD ENDED JUNE 30, 2018 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated NET SALES $ — $ 118,783 $ — $ 2,243,838 $ 459,571 $ (60,500 ) $ 2,761,692 COST OF SALES — 68,022 — 895,381 278,545 (60,500 ) 1,181,448 GROSS PROFIT — 50,761 — 1,348,457 181,026 — 1,580,244 SELLING AND ADMINISTRATIVE EXPENSES — 74,708 — 198,652 53,713 — 327,073 AMORTIZATION OF INTANGIBLE ASSETS — 1,038 — 46,533 6,222 — 53,793 (LOSS) INCOME FROM OPERATIONS — (24,985 ) — 1,103,272 121,091 — 1,199,378 INTEREST EXPENSE (INCOME) - NET — 478,341 2,569 (4 ) 8,870 — 489,776 REFINANCING COSTS — 5,839 71 — — — 5,910 EQUITY IN INCOME OF SUBSIDIARIES (728,299 ) (913,523 ) — — — 1,641,822 — INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 728,299 404,358 (2,640 ) 1,103,276 112,221 (1,641,822 ) 703,692 INCOME TAX PROVISION — (323,941 ) — 283,975 12,416 — (27,550 ) INCOME FROM CONTINUING OPERATIONS 728,299 728,299 (2,640 ) 819,301 99,805 (1,641,822 ) 731,242 (LOSS) INCOME FROM DISCONTINUED OPERATIONS, NET OF TAX — — — (2,310 ) (633 ) — (2,943 ) NET INCOME $ 728,299 $ 728,299 $ (2,640 ) $ 816,991 $ 99,172 $ (1,641,822 ) $ 728,299 OTHER COMPREHENSIVE INCOME, NET OF TAX 61,426 66,480 — 8,553 (15,123 ) (59,910 ) 61,426 TOTAL COMPREHENSIVE INCOME $ 789,725 $ 794,779 $ (2,640 ) $ 825,544 $ 84,049 $ (1,701,732 ) $ 789,725 TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING STATEMENT OF INCOME AND COMPREHENSIVE INCOME FOR THE THIRTY-NINE WEEK PERIOD ENDED JULY 1, 2017 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated NET SALES $ — $ 102,467 $ — $ 2,161,060 $ 380,843 $ (63,969 ) $ 2,580,401 COST OF SALES — 56,826 — 897,838 235,393 (63,044 ) 1,127,013 GROSS PROFIT — 45,641 — 1,263,222 145,450 (925 ) 1,453,388 SELLING AND ADMINISTRATIVE EXPENSES 69 73,480 — 195,700 41,428 — 310,677 AMORTIZATION OF INTANGIBLE ASSETS — 635 — 64,072 6,115 — 70,822 (LOSS) INCOME FROM OPERATIONS (69 ) (28,474 ) — 1,003,450 97,907 (925 ) 1,071,889 INTEREST EXPENSE (INCOME) - NET — 452,867 — (816 ) (6,065 ) — 445,986 REFINANCING COSTS — 35,936 — — — — 35,936 EQUITY IN INCOME OF SUBSIDIARIES (443,498 ) (984,479 ) — — — 1,427,977 — INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 443,429 467,202 — 1,004,266 103,972 (1,428,902 ) 589,967 INCOME TAX PROVISION — 23,704 — 116,846 5,023 — 145,573 INCOME FROM CONTINUING OPERATIONS 443,429 443,498 — 887,420 98,949 (1,428,902 ) 444,394 (LOSS) INCOME FROM DISCONTINUED OPERATIONS, NET OF TAX — — — (782 ) (183 ) — (965 ) NET INCOME $ 443,429 $ 443,498 $ — $ 886,638 $ 98,766 $ (1,428,902 ) $ 443,429 OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX 37,091 32,569 — 16,985 6,753 (56,307 ) 37,091 TOTAL COMPREHENSIVE INCOME $ 480,520 $ 476,067 $ — $ 903,623 $ 105,519 $ (1,485,209 ) $ 480,520 TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS FOR THE THIRTY-NINE WEEK PERIOD ENDED JUNE 30, 2018 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES $ — $ (291,416 ) $ 2,110 $ 863,173 $ 117,043 $ — $ 690,910 INVESTING ACTIVITIES: Capital expenditures — (1,372 ) — (41,999 ) (6,726 ) — (50,097 ) Payments made in connection with acquisitions — (582,262 ) — — — — (582,262 ) Proceeds in connection with sale of discontinued operations — 57,686 — — — — 57,686 Net cash used in investing activities — (525,948 ) — (41,999 ) (6,726 ) — (574,673 ) FINANCING ACTIVITIES: Intercompany activities 14,035 1,392,169 (492,371 ) (820,946 ) (92,887 ) — — Proceeds from exercise of stock options 40,621 — — — — — 40,621 Special dividend and dividend equivalent payments (56,148 ) — — — — — (56,148 ) Proceeds from term loans, net — 12,779,772 — — — — 12,779,772 Repayment on term loans — (12,155,198 ) — — — — (12,155,198 ) Proceeds from 6.875% 2026 Notes, net — — 490,411 — — — 490,411 Other — (9,904 ) — — — — (9,904 ) Net cash (used in) provided by financing activities (1,492 ) 2,006,839 (1,960 ) (820,946 ) (92,887 ) — 1,089,554 EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS — — — — (2,979 ) — (2,979 ) (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS (1,492 ) 1,189,475 150 228 14,451 — 1,202,812 CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD 2,416 439,473 — (203 ) 208,875 — 650,561 CASH AND CASH EQUIVALENTS, END OF PERIOD $ 924 $ 1,628,948 $ 150 $ 25 $ 223,326 $ — $ 1,853,373 TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS FOR THE THIRTY-NINE WEEK PERIOD ENDED JULY 1, 2017 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES $ (69 ) $ (529,423 ) $ — $ 1,111,978 $ (27,965 ) $ 695 $ 555,216 INVESTING ACTIVITIES: Capital expenditures — (1,479 ) — (50,480 ) (3,712 ) — (55,671 ) Payments made in connection with acquisitions — (135,507 ) — — — — (135,507 ) Payments made in connection with acquisition of discontinued operations — (79,695 ) — — — — (79,695 ) Net cash used in investing activities — (216,681 ) — (50,480 ) (3,712 ) — (270,873 ) FINANCING ACTIVITIES: Intercompany activities 1,735,094 (751,701 ) — (1,064,658 ) 81,960 (695 ) — Proceeds from exercise of stock options 18,046 — — — — — 18,046 Special dividend and dividend equivalent payments (1,376,034 ) — — — — — (1,376,034 ) Treasury stock repurchased (389,821 ) — — — — — (389,821 ) Proceeds from term loans, net — 1,132,755 — — — — 1,132,755 Repayment on term loans — (48,453 ) — — — — (48,453 ) Cash tender and redemption of the 2021 Notes, including premium — (528,847 ) — — — — (528,847 ) Proceeds from additional 2025 Notes offering, net — 300,517 — — — — 300,517 Other — (10,777 ) — — — — (10,777 ) Net cash (used in) provided by financing activities (12,715 ) 93,494 — (1,064,658 ) 81,960 (695 ) (902,614 ) EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS — — — — 1,833 — 1,833 (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS (12,784 ) (652,610 ) — (3,160 ) 52,116 — (616,438 ) CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD 13,560 1,421,251 — 8,808 143,375 — 1,586,994 CASH AND CASH EQUIVALENTS, END OF PERIOD $ 776 $ 768,641 $ — $ 5,648 $ 195,491 $ — $ 970,556

RECENT ACCOUNTING PRONOUNCEME24

RECENT ACCOUNTING PRONOUNCEMENTS (Policies)	9 Months Ended
	Jun. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, which created a new topic in the Accounting Standards Codification (“ASC”) 606, “Revenue From Contracts With Customers .” In addition to superseding and replacing nearly all existing U.S. GAAP revenue recognition guidance, including industry-specific guidance, ASC 606 establishes a new control-based revenue recognition model. The new revenue standards may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized as of the date of adoption. The guidance is effective for the Company for annual reporting periods, including interim periods therein, beginning October 1, 2018, which will be the Company’s date of adoption. The Company will use the modified retrospective method. The Company is continuing to evaluate the impact of the standard. For each reporting unit, we have evaluated a representative sample of contracts and other agreements with our customers and evaluated the provisions contained within these contracts and agreements in consideration of the five step model specified within ASC 606. We are in the process of documenting the impact of the standard on our current accounting policies and practices in order to identify material differences, if any, that would result from applying the new requirements to our revenue contracts. We continue to make progress on our assessment of ASC 606 and are also in the process of evaluating the impact on changes to our business processes, systems, and controls to support recognition and disclosure requirements under ASC 606. In February 2016, the FASB issued ASU 2016-02, “Leases (ASC 842),” which will require that a lessee recognize assets and liabilities on the balance sheet for all leases with a lease term of more than twelve months, with the result being the recognition of a right of use asset and a lease liability. Additionally, in July 2018, the FASB issued ASU 2018-10, "Codification Improvements to ASC 842, Leases" which provides narrow amendments to clarify how to apply certain aspects of the new leases standard. The new leases standard guidance is effective for the Company for annual reporting periods, including interim periods therein, beginning October 1, 2019, with early adoption permitted. The Company is currently evaluating the impact of adopting this standard on its consolidated financial statements and disclosures. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments (ASU 2016-13)," which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. ASU 2016-13 is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted for annual and interim periods beginning after December 15, 2018. The Company is currently evaluating the impact of adopting this standard on its consolidated financial statements and disclosures. In August 2016, the FASB issued ASU 2016-15, "Statement of Cash Flows—Classification of Certain Cash Receipts and Cash Payments," which clarifies existing guidance related to accounting for cash receipts and cash payments and classification on the statement of cash flows. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, with early adoption permitted. The Company elected to early adopt this standard in the fourth quarter of fiscal 2017. The adoption of this standard did not have a material impact on its consolidated statement of cash flows. In January 2017, the FASB issued ASU 2017-04, “Simplifying the Test for Goodwill Impairment,” to eliminate Step 2 from the goodwill impairment test in order to simplify the subsequent measurement of goodwill. The guidance is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The adoption of this standard is not expected to have a material impact on its consolidated financial statements and disclosures. In March 2017, the FASB issued ASU 2017-07, "Compensation—Retirement Benefits (ASC 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost," that will change how employers that sponsor defined benefit and/or other postretirement benefit plans present the net periodic benefit cost in the income statement. Under the new guidance, employers will present the service cost component of the net periodic benefit cost in the same income statement line item(s) as other employee compensation costs arising from services rendered during the period. In addition, only the service cost component will be eligible for capitalization in assets. Employers will present the other components separately from the line item(s) that includes the service cost and outside of any subtotal of operating income, if one is presented. Employers will have to disclose the line(s) used to present the other components of net periodic benefit cost, if the components are not presented separately in the income statement.The standard is effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within the fiscal year. Early adoption is permitted, including adoption in any interim period for which financial statements have not yet been issued. The adoption of this standard is not expected to have a material impact on our consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, "Compensation—Stock Compensation (ASC 718): Scope of Modification Accounting," which provides clarity on which changes to the terms or conditions of share-based payment awards require an entity to apply the modification accounting provisions required in ASC 718. The standard is effective for all entities for annual periods beginning after December 15, 2017, with early adoption permitted, including adoption in any interim period for which financial statements have not yet been issued. The adoption of this standard is not expected to have a material impact on our consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, “Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities,” which amends the FASB’s hedge accounting model to enable entities to better portray their risk management activities in financial statements. The guidance eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in the fair value of a hedging instrument to be presented in the same income statement line as the hedged item. The guidance also eases certain documentation and assessment requirements and modifies the accounting for components excluded from the assessment of hedge effectiveness. ASU 2017-12 is effective for the Company for annual reporting periods, including interim periods therein, beginning October 1, 2018, with early adoption permitted. As early adoption is permissible, the Company adopted the pronouncement beginning October 1, 2017. Changes were applied prospectively in accordance with the standard and prior periods were not adjusted. The adoption of this standard did not have a material impact on our consolidated financial statements and disclosures. In February 2018, the FASB issued ASU 2018-02, "Income Statement - Reporting Comprehensive Income (ASC 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income," which gives entities the option to reclassify tax effects stranded in accumulated other comprehensive income as a result of the Tax Cuts and Jobs Act (the "Act") into retained earnings. The guidance allows entities to reclassify from accumulated other comprehensive income to retained earnings stranded tax effects resulting from the Act's new federal corporate income tax rate. The guidance also allows entities to elect to reclassify other stranded tax effects that relate to the Act but do not directly relate to the change in the federal tax rate (e.g., state taxes, changing from a worldwide tax system to a territorial system). Tax effects that are stranded in accumulated other comprehensive income for other reasons (e.g., prior changes in tax law, a change in valuation allowance) may not be reclassified. The standard is effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within the fiscal year. Early adoption is permitted, including adoption in any interim period for which financial statements have not yet been issued. Entities have the option to apply the guidance retrospectively or in the period of adoption. The adoption of this standard is not expected to have a material impact on our consolidated financial statements. In March 2018, the FASB issued ASU 2018-05, “Income Taxes (ASC 740), Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118.” The ASU adds various SEC paragraphs pursuant to the issuance of the December 2017 SEC Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”), which was effective immediately. The SEC issued SAB 118 to address concerns about reporting entities’ ability to timely comply with the accounting requirements to recognize all of the effects of the Tax Cuts and Jobs Act in the period of enactment. SAB 118 allows disclosure that timely determination of some or all of the income tax effects from the Tax Cuts and Jobs Act are incomplete by the due date of the financial statements and if possible to provide a reasonable estimate. We have accounted for the tax effects of the Tax Cuts and Jobs Act under the guidance of SAB 118, on a provisional basis. Our accounting for certain income tax effects is incomplete, but we have determined reasonable estimates for those effects and have recorded provisional amounts in our condensed consolidated financial statements. Refer to Note 9, "Income Taxes," for further information.

ACQUISITIONS AND DIVESTITURES (

ACQUISITIONS AND DIVESTITURES (Tables)	9 Months Ended
	Jun. 30, 2018
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The following table summarizes the purchase price allocation of the estimated fair values of the assets acquired and liabilities assumed at the transaction date (in thousands). Assets acquired: Current assets, excluding cash acquired $ 58,021 Property, plant, and equipment 4,124 Intangible assets 36,000 Goodwill 460,707 Other 86 Total assets acquired 558,938 Liabilities assumed: Current liabilities 9,213 Other noncurrent liabilities 17,226 Total liabilities assumed 26,439 Net assets acquired $ 532,499

EARNINGS PER SHARE (TWO-CLASS26

EARNINGS PER SHARE (TWO-CLASS METHOD) (Tables)	9 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted earnings per share (in thousands, except per share data): Thirteen Week Periods Ended Thirty-Nine Week Periods Ended June 30, 2018 July 1, 2017 June 30, 2018 July 1, 2017 Numerator for earnings per share: Net income from continuing operations $ 217,391 $ 169,832 $ 731,242 $ 444,394 Less dividends paid on participating securities — — (56,148 ) (95,971 ) $ 217,391 $ 169,832 $ 675,094 $ 348,423 Net loss from discontinued operations (145 ) (779 ) (2,943 ) (965 ) Net income applicable to common stock - basic and diluted $ 217,246 $ 169,053 $ 672,151 $ 347,458 Denominator for basic and diluted earnings per share under the two-class method: Weighted average common shares outstanding 52,470 51,932 52,241 52,718 Vested options deemed participating securities 3,127 2,958 3,357 3,055 Total shares for basic and diluted earnings per share 55,597 54,890 55,598 55,773 Net earnings per share from continuing operations - basic and diluted $ 3.91 $ 3.09 $ 12.14 $ 6.25 Net loss per share from discontinued operations - basic and diluted — (0.01 ) (0.05 ) (0.02 ) Net earnings per share $ 3.91 $ 3.08 $ 12.09 $ 6.23

INVENTORIES (Tables)

INVENTORIES (Tables)	9 Months Ended
	Jun. 30, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories consist of the following (in thousands): June 30, 2018 September 30, 2017 Raw materials and purchased component parts $ 553,006 $ 496,899 Work-in-progress 220,883 187,009 Finished goods 139,395 131,548 Total 913,284 815,456 Reserves for excess and obsolete inventory (98,033 ) (84,775 ) Inventories - Net $ 815,251 $ 730,681

INTANGIBLE ASSETS (Tables)

INTANGIBLE ASSETS (Tables)	9 Months Ended
	Jun. 30, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Schedule of Acquired Intangible Assets by Major Class [Table Text Block]	Intangible assets acquired during the thirty-nine week period ended June 30, 2018 were as follows (in thousands): Gross Amount Amortization Period Intangible assets not subject to amortization: Goodwill $ 460,961 Trademarks and trade names 17,300 478,261 Intangible assets subject to amortization: Technology 20,600 20 years Order backlog 8,300 1 year Customer relationships 10,000 20 years 38,900 15.9 years Total $ 517,161
Intangible Assets Subject to Amortization	Other intangible assets - net in the condensed consolidated balance sheets consist of the following (in thousands): June 30, 2018 September 30, 2017 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Trademarks and trade names $ 746,859 $ — $ 746,859 $ 729,931 $ — $ 729,931 Technology 1,309,675 399,828 909,847 1,292,719 351,638 941,081 Order backlog 11,000 4,275 6,725 29,000 26,668 2,332 Other 73,226 21,583 51,643 63,599 19,081 44,518 Total $ 2,140,760 $ 425,686 $ 1,715,074 $ 2,115,249 $ 397,387 $ 1,717,862
Summary of Changes in Carrying Value of Goodwill	The following is a summary of changes in the carrying value of goodwill by segment from September 30, 2017 through June 30, 2018 (in thousands): Power & Control Airframe Non- aviation Total Balance - September 30, 2017 $ 3,269,981 $ 2,382,082 $ 93,275 $ 5,745,338 Goodwill acquired during the year 460,707 254 — 460,961 Purchase price allocation adjustments 5,354 — — 5,354 Currency translation adjustment — (2,401 ) — (2,401 ) Other (192 ) 187 — (5 ) Balance - June 30, 2018 $ 3,735,850 $ 2,380,122 $ 93,275 $ 6,209,247

DEBT (Tables)

DEBT (Tables)	9 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Schedule of Debt	The Company’s debt consists of the following (in thousands): June 30, 2018 Gross Amount Debt Issuance Costs Original Issue Discount or Premium Net Amount Short-term borrowings—trade receivable securitization facility $ 300,000 $ (44 ) $ — $ 299,956 Term loans $ 7,619,039 $ (73,105 ) $ (21,984 ) $ 7,523,950 5.50% senior subordinated notes due 2020 (2020 Notes) 550,000 (2,451 ) — 547,549 6.00% senior subordinated notes due 2022 (2022 Notes) 1,150,000 (5,861 ) — 1,144,139 6.50% senior subordinated notes due 2024 (2024 Notes) 1,200,000 (7,160 ) — 1,192,840 6.50% senior subordinated notes due 2025 (2025 Notes) 750,000 (3,637 ) 3,772 750,135 6.375% senior subordinated notes due 2026 (6.375% 2026 Notes) 950,000 (8,050 ) — 941,950 6.875% senior subordinated notes due 2026 (6.875% 2026 Notes) 500,000 (5,038 ) (3,722 ) 491,240 12,719,039 (105,302 ) (21,934 ) 12,591,803 Less current portion 76,427 (634 ) — 75,793 Long-term debt $ 12,642,612 $ (104,668 ) $ (21,934 ) $ 12,516,010 September 30, 2017 Gross Amount Debt Issuance Costs Original Issue Discount or Premium Net Amount Short-term borrowings—trade receivable securitization facility $ 300,000 $ (413 ) $ — $ 299,587 Term loans $ 6,973,009 $ (64,104 ) $ (18,948 ) $ 6,889,957 5.50% 2020 Notes 550,000 (3,243 ) — 546,757 6.00% 2022 Notes 1,150,000 (6,941 ) — 1,143,059 6.50% 2024 Notes 1,200,000 (8,042 ) — 1,191,958 6.50% 2025 Notes 750,000 (4,033 ) 4,182 750,149 6.375% 2026 Notes 950,000 (8,806 ) — 941,194 11,573,009 (95,169 ) (14,766 ) 11,463,074 Less current portion 70,031 (577 ) — 69,454 Long-term debt $ 11,502,978 $ (94,592 ) $ (14,766 ) $ 11,393,620

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Jun. 30, 2018
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 thousands): June 30, 2018 September 30, 2017 Level Carrying Amount Fair Value Carrying Amount Fair Value Assets: Cash and cash equivalents 1 $ 1,853,373 $ 1,853,373 $ 650,561 $ 650,561 Interest rate cap agreements (1) 2 31,948 31,948 12,904 12,904 Interest rate swap agreements (2) 2 5,458 5,458 — — Interest rate swap agreements (1) 2 40,919 40,919 2,905 2,905 Liabilities: Interest rate swap agreements (3) 2 1,554 1,554 20,740 20,740 Interest rate swap agreements (4) 2 4,153 4,153 9,731 9,731 Short-term borrowings - trade receivable securitization facility (5) 1 299,956 299,956 299,587 299,587 Long-term debt, including current portion: Term loans (5) 2 7,523,950 7,536,675 6,889,957 6,965,628 5.50% 2020 Notes (5) 1 547,549 548,625 546,757 558,250 6.00% 2022 Notes (5) 1 1,144,139 1,155,750 1,143,059 1,178,750 6.50% 2024 Notes (5) 1 1,192,840 1,215,000 1,191,958 1,236,000 6.50% 2025 Notes (5) 1 750,135 757,500 750,149 776,807 6.375% 2026 Notes (5) 1 941,950 942,875 941,194 971,375 6.875% 2026 Notes (5) 1 491,240 506,250 — — (1) Included in other non-current assets on the condensed consolidated balance sheet. (2) Included in prepaid expenses and other on the condensed consolidated balance sheet. (3) Included in accrued liabilities on the condensed consolidated balance sheet. (4) Included in other non-current liabilities on the condensed consolidated balance sheet. (5) The carrying amount of the debt instrument is presented net of debt issuance costs, premium and discount. Refer to Note 8, "Debt," for gross carrying amounts.

DERIVATIVES AND HEDGING ACTIV31

DERIVATIVES AND HEDGING ACTIVITIES (Tables)	9 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	The following table summarizes the Company's interest rate swap agreements: Aggregate Notional Amount (in millions) Start Date End Date Related Term Loans Conversion of Related Variable Rate Debt to Fixed Rate of: $750 3/31/2016 6/30/2020 Tranche E 5.3% (2.8% plus the 2.5% margin percentage) $500 6/29/2018 3/31/2025 Tranche E 5.5% (3.0% plus the 2.5% margin percentage) $750 6/30/2020 6/30/2022 Tranche E 5.0% (2.5% plus the 2.5% margin percentage) $1,500 6/30/2022 3/31/2025 Tranche E 5.6% (3.1% plus the 2.5% margin percentage) $1,000 9/30/2014 6/28/2019 Tranche F 4.9% (2.4% plus the 2.5% margin percentage) $1,000 6/28/2019 6/30/2021 Tranche F 4.3% (1.8% plus the 2.5% margin percentage) $1,400 6/30/2021 3/31/2023 Tranche F 5.5% (3.0% plus the 2.5% margin percentage) $500 12/30/2016 12/30/2021 Tranche G 4.4% (1.9% plus the 2.5% margin percentage) $400 9/30/2017 9/30/2022 Tranche G 4.4% (1.9% plus the 2.5% margin percentage) $900 12/31/2021 6/28/2024 Tranche G 5.6% (3.1% plus the 2.5% margin percentage) $400 9/30/2022 6/28/2024 Tranche G 5.5% (3.0% plus the 2.5% margin percentage) The following table summarizes the Company's interest rate cap agreements: Aggregate Notional Amount Start Date End Date Related Term Loans Offsets Variable Rate Debt Attributable to Fluctuations Above: $750 9/30/2015 6/30/2020 Tranche E Three month LIBO rate of 2.5% $750 6/30/2020 6/30/2022 Tranche E Three month LIBO rate of 2.5% $400 6/30/2016 6/30/2021 Tranche F Three month LIBO rate of 2.0% $400 12/30/2016 12/30/2021 Tranche G Three month LIBO rate of 2.5%
Schedule of Interest Rate Derivatives	June 30, 2018 September 30, 2017 Asset Liability Asset Liability Interest rate cap agreements $ 31,948 $ — $ 12,904 $ — Interest rate swap agreements 57,945 (17,275 ) 9,235 (36,801 ) Total 89,893 (17,275 ) 22,139 (36,801 ) Effect of counterparty netting (11,568 ) 11,568 (6,330 ) 6,330 Net derivatives as classified in the balance sheet (1) $ 78,325 $ (5,707 ) $ 15,809 $ (30,471 ) (1) Refer to Note 10, "Fair Value Measurements," for the condensed consolidated balance sheet classification of our interest rate swap and cap agreements.

SEGMENTS (Tables)

SEGMENTS (Tables)	9 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Net Sales by Reportable Segments	The following table presents net sales by reportable segment (in thousands): Thirteen Week Periods Ended Thirty-Nine Week Periods Ended June 30, 2018 July 1, 2017 June 30, 2018 July 1, 2017 Net sales to external customers Power & Control $ 546,905 $ 499,069 $ 1,558,083 $ 1,408,853 Airframe 398,596 362,871 1,101,771 1,072,044 Non-aviation 35,161 35,715 101,838 99,504 $ 980,662 $ 897,655 $ 2,761,692 $ 2,580,401
EBITDA Defined by Segment to Consolidated Income Before Taxes	The following table reconciles EBITDA As Defined by segment to consolidated income from continuing operations before income taxes (in thousands): Thirteen Week Periods Ended Thirty-Nine Week Periods Ended June 30, 2018 July 1, 2017 June 30, 2018 July 1, 2017 EBITDA As Defined Power & Control $ 288,202 $ 262,855 $ 808,539 $ 708,601 Airframe 196,746 184,091 541,171 535,600 Non-aviation 11,075 11,908 30,392 32,576 Total segment EBITDA As Defined 496,023 458,854 1,380,102 1,276,777 Unallocated corporate expenses 8,882 11,266 28,305 26,319 Total Company EBITDA As Defined 487,141 447,588 1,351,797 1,250,458 Depreciation and amortization expense 33,925 36,367 95,534 109,076 Interest expense - net 167,577 152,141 489,776 445,986 Acquisition-related costs 10,381 4,484 16,940 30,804 Stock compensation expense 13,708 11,580 36,411 32,707 Refinancing costs 4,159 345 5,910 35,936 Other, net (8,150 ) 6,824 3,534 5,982 Income from continuing operations before income taxes $ 265,541 $ 235,847 $ 703,692 $ 589,967
Total Assets by Segment	The following table presents total assets by segment (in thousands): June 30, 2018 September 30, 2017 Total assets Power & Control $ 5,712,597 $ 5,135,459 Airframe 3,977,451 3,923,172 Non-aviation 227,905 224,936 Corporate 1,886,524 614,594 Assets of discontinued operations — 77,500 $ 11,804,477 $ 9,975,661

ACCUMULATED OTHER COMPREHENSI33

ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)	9 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The following table presents the components of accumulated other comprehensive loss, net of taxes, for the thirty-nine week period ended June 30, 2018 (in thousands): Unrealized (loss) gain on derivatives designated and qualifying as cash flow hedges (1) Defined benefit pension plan activity Currency translation adjustment Total Balance at September 30, 2017 $ (26,669 ) $ (16,365 ) $ (42,109 ) $ (85,143 ) Current-period other comprehensive gain (loss) 63,742 — (4,355 ) 59,387 Amounts reclassified from AOCI related to interest rate swap and cap agreements 2,039 — — 2,039 Balance at June 30, 2018 $ 39,112 $ (16,365 ) $ (46,464 ) $ (23,717 ) (1) Unrealized (loss) gain represents interest rate swap and cap agreements, net of taxes of $(954) and $5,002 for the thirteen week periods ended June 30, 2018 and July 1, 2017 and $(25,679) and $(19,425) for the thirty-nine week period s ended June 30, 2018 and July 1, 2017 , respectively.
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]	A summary of reclassifications out of accumulated other comprehensive loss for the thirty-nine week period s ended June 30, 2018 and July 1, 2017 is provided below (in thousands): Amount reclassified Thirty-Nine Week Periods Ended Description of reclassifications out of accumulated other comprehensive loss June 30, 2018 July 1, 2017 Amortization from redesignated interest rate swap and cap agreements (1) $ 2,816 $ 2,870 Deferred tax benefit from redesignated interest rate swap and cap agreements (777 ) (1,072 ) Losses reclassified into earnings, net of tax $ 2,039 $ 1,798 (1) This component of accumulated other comprehensive loss is included in interest expense (see Note 11, “Derivatives and Hedging Activities,” for additional information).

DISCONTINUED OPERATIONS (Tables

DISCONTINUED OPERATIONS (Tables)	9 Months Ended
	Jun. 30, 2018
DISCONTINUED OPERATIONS [Abstract]
Disposal Groups, Including Discontinued Operations [Table Text Block]	The following is the summarized operating results for Schroth for the thirteen and thirty-nine week periods ended June 30, 2018 and July 1, 2017 (in thousands): Thirteen Week Period Ended Thirty-Nine Week Period Ended June 30, 2018 July 1, 2017 June 30, 2018 July 1, 2017 Net sales $ — $ 10,012 $ 11,808 $ 14,516 (Loss) Income from discontinued operations before income taxes — (779 ) 354 (965 ) Income tax benefit — — 2,016 — (Loss) Income from discontinued operations, net of tax — (779 ) 2,370 (965 ) Net loss on sale of discontinued operations, net of tax (145 ) — (5,313 ) — Loss from discontinued operations $ (145 ) $ (779 ) $ (2,943 ) $ (965 )

SUPPLEMENTAL GUARANTOR INFORM35

SUPPLEMENTAL GUARANTOR INFORMATION (Tables)	9 Months Ended
	Jun. 30, 2018
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Supplemental Condensed Consolidating Balance Sheet	TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING BALANCE SHEET AS OF JUNE 30, 2018 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated ASSETS CURRENT ASSETS: Cash and cash equivalents $ 924 $ 1,628,948 $ 150 $ 25 $ 223,326 $ — $ 1,853,373 Trade accounts receivable - Net — — — 22,003 648,401 (12,236 ) 658,168 Inventories - Net — 47,309 — 653,972 117,027 (3,057 ) 815,251 Prepaid expenses and other — 26,406 — 21,188 11,016 — 58,610 Total current assets 924 1,702,663 150 697,188 999,770 (15,293 ) 3,385,402 INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES (2,099,404 ) 10,325,919 1,096,125 8,600,056 2,177,711 (20,100,407 ) — PROPERTY, PLANT AND EQUIPMENT - NET — 15,585 — 314,510 50,380 — 380,475 GOODWILL — 128,764 — 5,419,486 660,997 — 6,209,247 OTHER INTANGIBLE ASSETS - NET — 16,583 — 1,453,885 244,606 — 1,715,074 OTHER — 79,366 — 29,159 5,754 — 114,279 TOTAL ASSETS $ (2,098,480 ) $ 12,268,880 $ 1,096,275 $ 16,514,284 $ 4,139,218 $ (20,115,700 ) $ 11,804,477 LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY CURRENT LIABILITIES: Current portion of long-term debt $ — $ 75,793 $ — $ — $ — $ — $ 75,793 Short-term borrowings - trade receivable securitization facility — — — — 299,956 — 299,956 Accounts payable — 15,974 — 115,763 36,550 (12,350 ) 155,937 Accrued liabilities — 109,607 4,679 124,531 46,667 — 285,484 Total current liabilities — 201,374 4,679 240,294 383,173 (12,350 ) 817,170 LONG-TERM DEBT — 12,024,770 491,240 — — — 12,516,010 DEFERRED INCOME TAXES — 299,043 — 100 58,537 — 357,680 OTHER NON-CURRENT LIABILITIES — 110,255 — 74,904 26,938 — 212,097 Total liabilities — 12,635,442 495,919 315,298 468,648 (12,350 ) 13,902,957 STOCKHOLDERS’ (DEFICIT) EQUITY (2,098,480 ) (366,562 ) 600,356 16,198,986 3,670,570 (20,103,350 ) (2,098,480 ) TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY $ (2,098,480 ) $ 12,268,880 $ 1,096,275 $ 16,514,284 $ 4,139,218 $ (20,115,700 ) $ 11,804,477 TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING BALANCE SHEET AS OF SEPTEMBER 30, 2017 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated ASSETS CURRENT ASSETS: Cash and cash equivalents $ 2,416 $ 439,473 $ — $ (203 ) $ 208,875 $ — $ 650,561 Trade accounts receivable - Net — — — 25,069 652,807 (41,749 ) 636,127 Inventories - Net — 47,051 — 571,712 114,018 (2,100 ) 730,681 Assets held-for-sale — — — 6,428 71,072 — 77,500 Prepaid expenses and other — 4,746 — 24,141 9,796 — 38,683 Total current assets 2,416 491,270 — 627,147 1,056,568 (43,849 ) 2,133,552 INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES (2,953,620 ) 10,263,999 — 7,599,210 966,675 (15,876,264 ) — PROPERTY, PLANT AND EQUIPMENT - NET — 16,032 — 261,434 47,458 — 324,924 GOODWILL — 85,905 — 4,996,034 663,399 — 5,745,338 OTHER INTANGIBLE ASSETS - NET — 27,620 — 1,438,006 252,236 — 1,717,862 OTHER — 20,316 — 27,567 6,102 — 53,985 TOTAL ASSETS $ (2,951,204 ) $ 10,905,142 $ — $ 14,949,398 $ 2,992,438 $ (15,920,113 ) $ 9,975,661 LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY CURRENT LIABILITIES: Current portion of long-term debt $ — $ 69,454 $ — $ — $ — $ — $ 69,454 Short-term borrowings - trade receivable securitization facility — — — — 299,587 — 299,587 Accounts payable — 14,712 — 137,948 37,667 (41,566 ) 148,761 Accrued liabilities — 180,916 — 103,902 51,070 — 335,888 Liabilities held-for-sale — — — — 17,304 — 17,304 Total current liabilities — 265,082 — 241,850 405,628 (41,566 ) 870,994 LONG-TERM DEBT — 11,393,620 — — — — 11,393,620 DEFERRED INCOME TAXES — 442,415 — (99 ) 58,633 — 500,949 OTHER NON-CURRENT LIABILITIES — 61,347 — 73,245 26,710 — 161,302 Total liabilities — 12,162,464 — 314,996 490,971 (41,566 ) 12,926,865 STOCKHOLDERS’ (DEFICIT) EQUITY (2,951,204 ) (1,257,322 ) — 14,634,402 2,501,467 (15,878,547 ) (2,951,204 ) TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY $ (2,951,204 ) $ 10,905,142 $ — $ 14,949,398 $ 2,992,438 $ (15,920,113 ) $ 9,975,661
Supplemental Condensed Consolidating Income Statement	TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING STATEMENT OF INCOME AND COMPREHENSIVE INCOME FOR THE THIRTY-NINE WEEK PERIOD ENDED JUNE 30, 2018 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated NET SALES $ — $ 118,783 $ — $ 2,243,838 $ 459,571 $ (60,500 ) $ 2,761,692 COST OF SALES — 68,022 — 895,381 278,545 (60,500 ) 1,181,448 GROSS PROFIT — 50,761 — 1,348,457 181,026 — 1,580,244 SELLING AND ADMINISTRATIVE EXPENSES — 74,708 — 198,652 53,713 — 327,073 AMORTIZATION OF INTANGIBLE ASSETS — 1,038 — 46,533 6,222 — 53,793 (LOSS) INCOME FROM OPERATIONS — (24,985 ) — 1,103,272 121,091 — 1,199,378 INTEREST EXPENSE (INCOME) - NET — 478,341 2,569 (4 ) 8,870 — 489,776 REFINANCING COSTS — 5,839 71 — — — 5,910 EQUITY IN INCOME OF SUBSIDIARIES (728,299 ) (913,523 ) — — — 1,641,822 — INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 728,299 404,358 (2,640 ) 1,103,276 112,221 (1,641,822 ) 703,692 INCOME TAX PROVISION — (323,941 ) — 283,975 12,416 — (27,550 ) INCOME FROM CONTINUING OPERATIONS 728,299 728,299 (2,640 ) 819,301 99,805 (1,641,822 ) 731,242 (LOSS) INCOME FROM DISCONTINUED OPERATIONS, NET OF TAX — — — (2,310 ) (633 ) — (2,943 ) NET INCOME $ 728,299 $ 728,299 $ (2,640 ) $ 816,991 $ 99,172 $ (1,641,822 ) $ 728,299 OTHER COMPREHENSIVE INCOME, NET OF TAX 61,426 66,480 — 8,553 (15,123 ) (59,910 ) 61,426 TOTAL COMPREHENSIVE INCOME $ 789,725 $ 794,779 $ (2,640 ) $ 825,544 $ 84,049 $ (1,701,732 ) $ 789,725 TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING STATEMENT OF INCOME AND COMPREHENSIVE INCOME FOR THE THIRTY-NINE WEEK PERIOD ENDED JULY 1, 2017 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated NET SALES $ — $ 102,467 $ — $ 2,161,060 $ 380,843 $ (63,969 ) $ 2,580,401 COST OF SALES — 56,826 — 897,838 235,393 (63,044 ) 1,127,013 GROSS PROFIT — 45,641 — 1,263,222 145,450 (925 ) 1,453,388 SELLING AND ADMINISTRATIVE EXPENSES 69 73,480 — 195,700 41,428 — 310,677 AMORTIZATION OF INTANGIBLE ASSETS — 635 — 64,072 6,115 — 70,822 (LOSS) INCOME FROM OPERATIONS (69 ) (28,474 ) — 1,003,450 97,907 (925 ) 1,071,889 INTEREST EXPENSE (INCOME) - NET — 452,867 — (816 ) (6,065 ) — 445,986 REFINANCING COSTS — 35,936 — — — — 35,936 EQUITY IN INCOME OF SUBSIDIARIES (443,498 ) (984,479 ) — — — 1,427,977 — INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 443,429 467,202 — 1,004,266 103,972 (1,428,902 ) 589,967 INCOME TAX PROVISION — 23,704 — 116,846 5,023 — 145,573 INCOME FROM CONTINUING OPERATIONS 443,429 443,498 — 887,420 98,949 (1,428,902 ) 444,394 (LOSS) INCOME FROM DISCONTINUED OPERATIONS, NET OF TAX — — — (782 ) (183 ) — (965 ) NET INCOME $ 443,429 $ 443,498 $ — $ 886,638 $ 98,766 $ (1,428,902 ) $ 443,429 OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX 37,091 32,569 — 16,985 6,753 (56,307 ) 37,091 TOTAL COMPREHENSIVE INCOME $ 480,520 $ 476,067 $ — $ 903,623 $ 105,519 $ (1,485,209 ) $ 480,520
Supplemental Condensed Consolidating Cash Flow Statement	TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS FOR THE THIRTY-NINE WEEK PERIOD ENDED JUNE 30, 2018 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES $ — $ (291,416 ) $ 2,110 $ 863,173 $ 117,043 $ — $ 690,910 INVESTING ACTIVITIES: Capital expenditures — (1,372 ) — (41,999 ) (6,726 ) — (50,097 ) Payments made in connection with acquisitions — (582,262 ) — — — — (582,262 ) Proceeds in connection with sale of discontinued operations — 57,686 — — — — 57,686 Net cash used in investing activities — (525,948 ) — (41,999 ) (6,726 ) — (574,673 ) FINANCING ACTIVITIES: Intercompany activities 14,035 1,392,169 (492,371 ) (820,946 ) (92,887 ) — — Proceeds from exercise of stock options 40,621 — — — — — 40,621 Special dividend and dividend equivalent payments (56,148 ) — — — — — (56,148 ) Proceeds from term loans, net — 12,779,772 — — — — 12,779,772 Repayment on term loans — (12,155,198 ) — — — — (12,155,198 ) Proceeds from 6.875% 2026 Notes, net — — 490,411 — — — 490,411 Other — (9,904 ) — — — — (9,904 ) Net cash (used in) provided by financing activities (1,492 ) 2,006,839 (1,960 ) (820,946 ) (92,887 ) — 1,089,554 EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS — — — — (2,979 ) — (2,979 ) (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS (1,492 ) 1,189,475 150 228 14,451 — 1,202,812 CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD 2,416 439,473 — (203 ) 208,875 — 650,561 CASH AND CASH EQUIVALENTS, END OF PERIOD $ 924 $ 1,628,948 $ 150 $ 25 $ 223,326 $ — $ 1,853,373 TRANSDIGM GROUP INCORPORATED CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS FOR THE THIRTY-NINE WEEK PERIOD ENDED JULY 1, 2017 (Amounts in thousands) TransDigm Group TransDigm Inc. TransDigm UK Subsidiary Guarantors Non- Guarantor Subsidiaries Eliminations Total Consolidated NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES $ (69 ) $ (529,423 ) $ — $ 1,111,978 $ (27,965 ) $ 695 $ 555,216 INVESTING ACTIVITIES: Capital expenditures — (1,479 ) — (50,480 ) (3,712 ) — (55,671 ) Payments made in connection with acquisitions — (135,507 ) — — — — (135,507 ) Payments made in connection with acquisition of discontinued operations — (79,695 ) — — — — (79,695 ) Net cash used in investing activities — (216,681 ) — (50,480 ) (3,712 ) — (270,873 ) FINANCING ACTIVITIES: Intercompany activities 1,735,094 (751,701 ) — (1,064,658 ) 81,960 (695 ) — Proceeds from exercise of stock options 18,046 — — — — — 18,046 Special dividend and dividend equivalent payments (1,376,034 ) — — — — — (1,376,034 ) Treasury stock repurchased (389,821 ) — — — — — (389,821 ) Proceeds from term loans, net — 1,132,755 — — — — 1,132,755 Repayment on term loans — (48,453 ) — — — — (48,453 ) Cash tender and redemption of the 2021 Notes, including premium — (528,847 ) — — — — (528,847 ) Proceeds from additional 2025 Notes offering, net — 300,517 — — — — 300,517 Other — (10,777 ) — — — — (10,777 ) Net cash (used in) provided by financing activities (12,715 ) 93,494 — (1,064,658 ) 81,960 (695 ) (902,614 ) EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS — — — — 1,833 — 1,833 (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS (12,784 ) (652,610 ) — (3,160 ) 52,116 — (616,438 ) CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD 13,560 1,421,251 — 8,808 143,375 — 1,586,994 CASH AND CASH EQUIVALENTS, END OF PERIOD $ 776 $ 768,641 $ — $ 5,648 $ 195,491 $ — $ 970,556

DESCRIPTION OF THE BUSINESS - N

DESCRIPTION OF THE BUSINESS - Narratives (Details)	Jun. 30, 2018
Accounting Policies [Abstract]
Percentage of ownership in subsidiary	100.00%

ACQUISITIONS AND DIVESTITURES -

ACQUISITIONS AND DIVESTITURES - Narratives (Details) - USD ($)	Apr. 24, 2018	Mar. 15, 2018	Jan. 26, 2018	Feb. 22, 2017	Jun. 30, 2018	Jul. 01, 2017	Sep. 30, 2017
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired					$ 582,262,000	$ 135,507,000
Minimum
Business Acquisition [Line Items]
Estimated useful life of aircraft (in years)					25 years
Maximum
Business Acquisition [Line Items]
Estimated useful life of aircraft (in years)					30 years
Extant [Member]
Business Acquisition [Line Items]
Business Acquisition Purchase Price Adjustment					$ 200,000
Tax benefit recognition period (in years)	15 years
Amount of goodwill expected to be tax deductible	$ 44,000,000
Payments to Acquire Businesses, Net of Cash Acquired	532,500,000
Amount of goodwill expected to not be tax deductible	$ 417,000,000
Kirkhill [Member]
Business Acquisition [Line Items]
Business Acquisition Purchase Price Adjustment					600,000
Amount of goodwill expected to be tax deductible		$ 0
Payments to Acquire Businesses, Net of Cash Acquired		$ 49,300,000
Third Quarter 2017 Acquisitions [Member]
Business Acquisition [Line Items]
Business Acquisition Purchase Price Adjustment					400,000		$ 1,000,000
Tax benefit recognition period (in years)	15 years
Amount of goodwill expected to be tax deductible					66,000,000
Payments to Acquire Businesses, Net of Cash Acquired						$ 106,700,000
Amount of goodwill expected to not be tax deductible					9,000,000
Schroth [Member]
Business Acquisition [Line Items]
Business acquisition cost				$ 89,700,000
Business Acquisition Purchase Price Adjustment					300,000
Payments to Acquire Businesses, Net of Cash Acquired				79,700,000
Business Combination, Consideration Transferred, Liabilities Incurred				$ 9,000,000	$ 8,500,000
Schroth [Member]
Business Acquisition [Line Items]
Divestiture, Sale Price			$ 61,400,000

ACQUISITIONS AND DIVESTITURES38

ACQUISITIONS AND DIVESTITURES - Business Combinations Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Apr. 24, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Goodwill	$ 6,209,247		$ 5,745,338
Extant [Member]
Business Acquisition [Line Items]
Current assets, excluding cash acquired		$ 58,021
Property, plant, and equipment		4,124
Intangible assets		36,000
Goodwill		460,707
Other		86
Total assets acquired		558,938
Current liabilities		9,213
Other noncurrent liabilities		17,226
Total liabilities assumed		26,439
Net assets acquired		$ 532,499

EARNINGS PER SHARE (TWO-CLASS39

EARNINGS PER SHARE (TWO-CLASS METHOD) - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Numerator for earnings per share:
INCOME FROM CONTINUING OPERATIONS	$ 217,391	$ 169,832	$ 731,242	$ 444,394
Less dividends paid on participating securities	0	0	(56,148)	(95,971)
Net Income Loss Attributable to Continuing Operations Available To Common Stockholders Basic And Vested Options Deemed Participating Securities	217,391	169,832	675,094	348,423
Loss from discontinued operations	(145)	(779)	(2,943)	(965)
Net income applicable to common stock - basic and diluted	$ 217,246	$ 169,053	$ 672,151	$ 347,458
Denominator for basic and diluted earnings per share under the two-class method, in shares:
Weighted average common shares outstanding	52,470	51,932	52,241	52,718
Vested options deemed participating securities	3,127	2,958	3,357	3,055
Basic and diluted (in shares)	55,597	54,890	55,598	55,773
Net earnings per share from continuing operations - basic and diluted	$ 3.91	$ 3.09	$ 12.14	$ 6.25
Net loss per share from discontinued operations - basic and diluted	0	(0.01)	(0.05)	(0.02)
Basic and diluted earnings per share (in dollars per share)	$ 3.91	$ 3.08	$ 12.09	$ 6.23

INVENTORIES - Schedule of Inven

INVENTORIES - Schedule of Inventory (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Inventory Disclosure [Abstract]
Raw materials and purchased component parts	$ 553,006	$ 496,899
Work-in-progress	220,883	187,009
Finished goods	139,395	131,548
Total	913,284	815,456
Reserves for excess and obsolete inventory	(98,033)	(84,775)
Inventories - Net	$ 815,251	$ 730,681

INTANGIBLE ASSETS - Intangible

INTANGIBLE ASSETS - Intangible Assets Subject to Amortization (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 2,140,760	$ 2,115,249
Intangible Assets, Accumulated Amortization	425,686	397,387
Total	1,715,074	1,717,862
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,309,675	1,292,719
Accumulated Amortization	399,828	351,638
Net	909,847	941,081
Order backlog
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	11,000	29,000
Accumulated Amortization	4,275	26,668
Net	6,725	2,332
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	73,226	63,599
Accumulated Amortization	21,583	19,081
Net	51,643	44,518
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill), Gross	746,859	729,931
Indefinite-Lived Intangible Assets, Accumulated Amortization	0	0
Intangible Assets (Excluding Goodwill), Net	$ 746,859	$ 729,931

INTANGIBLE ASSETS - Summary of

INTANGIBLE ASSETS - Summary of changes in carrying value of Goodwill (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2018USD ($)
Goodwill [Line Items]
Goodwill, Acquired During Period	$ 460,961
Goodwill [Roll Forward]
Balance at beginning of period	5,745,338
Purchase price allocation adjustments	5,354
Goodwill, Foreign Currency Translation Gain (Loss)	(2,401)
Currency translation adjustment	(5)
Balance at end of period	6,209,247
Power & Control
Goodwill [Line Items]
Goodwill, Acquired During Period	460,707
Goodwill [Roll Forward]
Balance at beginning of period	3,269,981
Purchase price allocation adjustments	5,354
Goodwill, Foreign Currency Translation Gain (Loss)	0
Currency translation adjustment	(192)
Balance at end of period	3,735,850
Airframe
Goodwill [Line Items]
Goodwill, Acquired During Period	254
Goodwill [Roll Forward]
Balance at beginning of period	2,382,082
Purchase price allocation adjustments	0
Goodwill, Foreign Currency Translation Gain (Loss)	(2,401)
Currency translation adjustment	187
Balance at end of period	2,380,122
Non- aviation
Goodwill [Line Items]
Goodwill, Acquired During Period	0
Goodwill [Roll Forward]
Balance at beginning of period	93,275
Purchase price allocation adjustments	0
Goodwill, Foreign Currency Translation Gain (Loss)	0
Currency translation adjustment	0
Balance at end of period	$ 93,275

INTANGIBLE ASSETS - Narratives

INTANGIBLE ASSETS - Narratives (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 19,224	$ 23,259	$ 53,793	$ 70,822
Estimated Amortization Expense, 2017	73,200		73,200
Estimated Amortization Expense, 2018	73,300		73,300
Estimated Amortization Expense, 2019	68,700		68,700
Estimated Amortization Expense, 2020	68,700		68,700
Estimated Amortization Expense, 2021	68,700		68,700
Estimated Amortization Expense, 2022	$ 68,700		$ 68,700

INTANGIBLE ASSETS - Acquired In

INTANGIBLE ASSETS - Acquired Intangibles (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2018USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill, Acquired During Period	$ 460,961
Indefinite-lived Intangible Assets Acquired	478,261
Finite-lived Intangible Assets Acquired	$ 38,900
Finite-Lived Intangible Asset, Useful Life	15 years 10 months 24 days
Intangible Assets, Acquired During the Period	$ 517,161
Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 20,600
Finite-Lived Intangible Asset, Useful Life	20 years
Order backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 8,300
Finite-Lived Intangible Asset, Useful Life	1 year
Customer-Related Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 10,000
Finite-Lived Intangible Asset, Useful Life	20 years
Goodwill [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill, Acquired During Period	$ 460,961
Trademarks and trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets Acquired	$ 17,300

DEBT - Schedule of Debt (Detail

DEBT - Schedule of Debt (Detail) - USD ($) $ in Thousands		Jun. 30, 2018	May 08, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Gross Amount		$ 12,719,039		$ 11,573,009
Debt Issuance Costs		(105,302)		(95,169)
Debt Instrument, Unamortized Discount (Premium), Net		(21,934)		(14,766)
Short-term borrowings - trade receivable securitization facility		299,956		299,587
Total debt outstanding		12,591,803		11,463,074
Long-term Debt, Current Maturities, Net		75,793		69,454
Long-term Debt, Excluding Current Maturities, Gross		12,642,612		11,502,978
Deferred Finance Costs, Excluding Current Maturities		(104,668)		(94,592)
Debt Instrument, Unamortized Discount, Excluding Current Maturities		(21,934)		(14,766)
Long-term debt		12,516,010		11,393,620
Term loans
Debt Instrument [Line Items]
Gross Amount		7,619,039		6,973,009
Debt Issuance Costs		(73,105)		(64,104)
Debt Instrument, Unamortized Discount (Premium), Net		(21,984)		(18,948)
Total debt outstanding	[1]	$ 7,523,950		$ 6,889,957
Senior Subordinated Notes | 5.50% senior subordinated notes due 2020 (2020 Notes)
Debt Instrument [Line Items]
Interest rate		5.50%		5.50%
Gross Amount		$ 550,000		$ 550,000
Debt Issuance Costs		(2,451)		(3,243)
Debt Instrument, Unamortized Discount (Premium), Net		0		0
Total debt outstanding	[1]	$ 547,549		$ 546,757
Senior Subordinated Notes | 6.00% senior subordinated notes due 2022 (2022 Notes)
Debt Instrument [Line Items]
Interest rate		6.00%		6.00%
Gross Amount		$ 1,150,000		$ 1,150,000
Debt Issuance Costs		(5,861)		(6,941)
Debt Instrument, Unamortized Discount (Premium), Net		0		0
Total debt outstanding	[1]	$ 1,144,139		$ 1,143,059
Senior Subordinated Notes | 6.50% senior subordinated notes due 2024 (2024 Notes)
Debt Instrument [Line Items]
Interest rate		6.50%		6.50%
Gross Amount		$ 1,200,000		$ 1,200,000
Debt Issuance Costs		(7,160)		(8,042)
Debt Instrument, Unamortized Discount (Premium), Net		0		0
Total debt outstanding	[1]	$ 1,192,840		$ 1,191,958
Senior Subordinated Notes | 6.50% senior subordinated notes due 2025 (2025 Notes)
Debt Instrument [Line Items]
Interest rate		6.50%		6.50%
Gross Amount		$ 750,000		$ 750,000
Debt Issuance Costs		(3,637)		(4,033)
Debt Instrument, Unamortized Discount (Premium), Net		3,772		4,182
Total debt outstanding	[1]	$ 750,135		$ 750,149
Senior Subordinated Notes | 6.375% senior subordinated notes due 2026 (6.375% 2026 Notes)
Debt Instrument [Line Items]
Interest rate		6.375%		6.375%
Gross Amount		$ 950,000		$ 950,000
Debt Issuance Costs		(8,050)		(8,806)
Debt Instrument, Unamortized Discount (Premium), Net		0		0
Total debt outstanding	[1]	$ 941,950		941,194
Senior Subordinated Notes | 6.875% senior subordinated noted due 2026 [Member]
Debt Instrument [Line Items]
Interest rate		6.875%	6.875%
Gross Amount		$ 500,000	$ 500,000
Debt Issuance Costs		(5,038)
Debt Instrument, Unamortized Discount (Premium), Net		(3,722)
Original Issue Discount or Premium		(3,800)
Total debt outstanding	[1]	491,240		0
Asset-backed Securities
Debt Instrument [Line Items]
Short-term borrowings—trade receivable securitization facility, Gross		300,000		300,000
Debt Issuance Costs		(44)		(413)
Debt Instrument, Unamortized Discount (Premium), Net		0		0
Short-term borrowings - trade receivable securitization facility	[1]	299,956		299,587
Less current portion
Debt Instrument [Line Items]
Debt Issuance Costs		(634)		(577)
Debt Instrument, Unamortized Discount (Premium), Net				0
Original Issue Discount or Premium		0
Long-term Debt, Current Maturities, Gross		76,427		70,031
Long-term Debt, Current Maturities, Net		$ 75,793		$ 69,454
[1]	The carrying amount of the debt instrument is presented net of debt issuance costs, premium and discount. Refer to Note 8, "Debt," for gross carrying amounts.

DEBT - Narratives (Details)

DEBT - Narratives (Details) - USD ($) $ in Thousands	May 08, 2018	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Sep. 30, 2017
Debt Instrument [Line Items]
Interest Payable, Current		$ 88,900		$ 88,900		$ 82,200
Gross Amount		12,719,039		12,719,039		11,573,009
Refinancing Costs		4,159	$ 345	5,910	$ 35,936
Line of Credit Facility, Maximum Borrowing Capacity		600,000		600,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Refinancing Costs				200
Debt Issuance Costs, Gross		400		400
Letters of Credit Outstanding, Amount		14,600		14,600
Line of Credit Facility, Remaining Borrowing Capacity		585,400		585,400
Fourth Amendment to Second Amended And Restated Credit Agreement [Member] | Fourth Amendment to Second Amended And Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Refinancing Costs				700
Debt Issuance Costs, Gross		2,900		2,900
Senior Subordinated Notes | 7 1/2% senior subordinated notes due 2021 (2021 Notes)
Debt Instrument [Line Items]
Write off of Deferred Debt Issuance Cost				500
Senior Subordinated Notes | 6.50% senior subordinated notes due 2025 (2025 Notes)
Debt Instrument [Line Items]
Gross Amount		$ 750,000		$ 750,000		$ 750,000
Interest rate		6.50%		6.50%		6.50%
Senior Subordinated Notes | 6.875% senior subordinated noted due 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		$ 3,800		$ 3,800
Gross Amount	$ 500,000	$ 500,000		$ 500,000
Debt Instrument, Redemption Price, Percentage	99.24%
Interest rate	6.875%	6.875%		6.875%
Refinancing Costs				$ 600
Debt Issuance Costs, Gross		$ 5,100		5,100
Term loans
Debt Instrument [Line Items]
Gross Amount		7,619,039		7,619,039		$ 6,973,009
Term loans | New Tranche E Term Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		4,700		4,700
Debt Instrument, Face Amount		1,322,000		1,322,000
Write off of Deferred Debt Issuance Cost				300
Refinancing Costs				2,600
Debt Issuance Costs, Gross		7,000		7,000
Term loans | New Tranche F Term Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		3,578,000		3,578,000
Write off of Deferred Debt Issuance Cost				300
Debt Issuance Costs, Gross		2,000		2,000
Term loans | New Tranche E Term Loans - Q1 2018 [Member] [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		1,503,000		1,503,000
Term loans | New Tranche F Term Loans - Q1 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		1,000		1,000
Debt Instrument, Face Amount		2,857,000		2,857,000
Term loans | Existing Tranche D amount Converted to Tranche F [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		798,000		$ 798,000
Term loans | Tranche E and Tranche F [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				2.75%
Term loans | Tranche F
Debt Instrument [Line Items]
Write off of Deferred Debt Issuance Cost				$ 200
Term loans | New Tranche G Term Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		1,809,000		$ 1,809,000
Term loans | Tranche G [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				2.50%
Write off of Deferred Debt Issuance Cost				$ 200
Term loans | Incremental New Tranche E Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		933,000		$ 933,000
Term loans | New Tranche E and Tranche F [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				2.50%
Refinancing Facility Agreement to the Second Amended and Restated Credit Agreement [Member] | Refinancing Facility Agreement to the Second Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Refinancing Costs				$ 300
Debt Issuance Costs, Gross		$ 500		500
Amendment No.5 to the Second Amended and Restated Credit Agreement [Member] | Amendment No.5 to the Second Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Refinancing Costs				$ 7,200

INCOME TAXES - Narratives (Deta

INCOME TAXES - Narratives (Details) - USD ($) $ in Millions	Jan. 01, 2018	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Sep. 30, 2018	Sep. 30, 2017
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent				35.00%
Effective income tax rate		18.10%	28.00%	(3.90%)	24.70%
Unrecognized tax benefits		$ 10.3		$ 10.3			$ 8.7
Tax rate effect		10.2		10.2			$ 8.7
Reduction in tax position in next 12 months		$ 1.6		1.6
U.S. Tax Cuts and Jobs Act Effective 2018 [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Deferred Federal Income Tax Expense (Benefit)				170.2
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount				23.1
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount				$ 147.1
U.S. Tax Cuts and Jobs Act Effective 2018 [Member] | Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent						24.50%

FAIR VALUE MEASUREMENTS - Carry

FAIR VALUE MEASUREMENTS - Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands		Jun. 30, 2018	Sep. 30, 2017		Jul. 01, 2017	Sep. 30, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		$ 1,853,373	$ 650,561		$ 970,556	$ 1,586,994
Short-term borrowings - trade receivable securitization facility		299,956	299,587
Long-term Debt		12,591,803	11,463,074
Other Noncurrent Assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Cash Flow Hedge Asset at Carrying Value	[1]	31,948	12,904
Interest rate cap agreements	[1]	40,919	2,905
Prepaid Expenses and Other Current Assets [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate cap agreements	[2]	5,458	0
Accrued Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements	[3]	1,554	20,740
Other Noncurrent Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements	[4]	4,153	9,731
Term loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	[5]	7,523,950	6,889,957
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Fair Value		1,853,373	650,561
Level 2 | Other Noncurrent Assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate cap agreements, Fair Value	[1]	31,948	12,904
Interest Rate Swap Asset at Fair Value	[1]	40,919	2,905
Level 2 | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Swap Asset at Fair Value	[2]	5,458	0
Level 2 | Accrued Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements, Fair Value	[3]	1,554	20,740
Level 2 | Other Noncurrent Liabilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements, Fair Value	[4]	4,153	9,731
Level 2 | Term loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion, Fair Value		7,536,675	6,965,628
5.50% senior subordinated notes due 2020 (2020 Notes) | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	[5]	547,549	546,757
5.50% senior subordinated notes due 2020 (2020 Notes) | Level 1 | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion, Fair Value		548,625	558,250
6.00% senior subordinated notes due 2022 (2022 Notes) | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	[5]	1,144,139	1,143,059
6.00% senior subordinated notes due 2022 (2022 Notes) | Level 1 | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion, Fair Value		1,155,750	1,178,750
6.50% senior subordinated notes due 2024 (2024 Notes) | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	[5]	1,192,840	1,191,958
6.50% senior subordinated notes due 2024 (2024 Notes) | Level 1 | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion, Fair Value		1,215,000	1,236,000
6.50% senior subordinated notes due 2025 (2025 Notes) | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	[5]	750,135	750,149
6.50% senior subordinated notes due 2025 (2025 Notes) | Level 1 | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion, Fair Value		757,500	776,807
6.375% senior subordinated notes due 2026 (6.375% 2026 Notes) | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	[5]	941,950	941,194
6.375% senior subordinated notes due 2026 (6.375% 2026 Notes) | Level 1 | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion, Fair Value		942,875	971,375
6.875% senior subordinated noted due 2026 [Member] | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	[5]	491,240	0
6.875% senior subordinated noted due 2026 [Member] | Level 1 | Senior Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion, Fair Value		506,250	0
Asset-backed Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings - trade receivable securitization facility	[5]	299,956	299,587
Asset-backed Securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings - trade receivable securitization facility, Fair Value		$ 299,956	$ 299,587	[5]
[1]	Included in other non-current assets on the condensed consolidated balance sheet.
[2]	Included in prepaid expenses and other on the condensed consolidated balance sheet.
[3]	Included in accrued liabilities on the condensed consolidated balance sheet.
[4]	Included in other non-current liabilities on the condensed consolidated balance sheet.
[5]	The carrying amount of the debt instrument is presented net of debt issuance costs, premium and discount. Refer to Note 8, "Debt," for gross carrying amounts.

DERIVATIVES AND HEDGING ACTIV49

DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Notional Amounts of Outstanding Derivatives (Details) - USD ($)		9 Months Ended
		Jun. 30, 2018	Jul. 01, 2017
Tranche F | Interest Rate Swap
Derivative [Line Items]
Derivative, Notional Amount		$ 1,000,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Tranche F | Interest rate swap June 28, 2016 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 1,000,000,000
Tranche F | Interest rate swap beginning June 30, 2021 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 1,400,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Tranche F | Interest Rate Cap
Derivative [Line Items]
Derivative, Cap Interest Rate		2.50%
Tranche F | Interest rate cap agreements beginning June 30, 2016 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 400,000,000
Derivative, Cap Interest Rate		2.00%
Tranche E | Interest rate cap beginning September 30, 2015 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 750,000,000
Derivative, Cap Interest Rate		2.50%
Tranche E | Interest rate cap beginning June 30, 2020 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 750,000,000
Tranche E | Interest rate swap beginning March 31, 2016 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 750,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Tranche E | Interest rate swap beginning June 29, 2018 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 500,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Tranche E | Interest rate swap beginning June 30, 2020 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 750,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Tranche E | Interest rate swap beginning June 30, 2022 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 1,500,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Tranche G [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative, Notional Amount		$ 500,000,000
Derivative, Fixed Interest Rate		4.40%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Tranche G [Member] | Interest Rate Cap
Derivative [Line Items]
Derivative, Notional Amount		$ 400,000,000
Tranche G [Member] | Interest rate swap beginning September 30, 2017 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 400,000,000
Derivative, Fixed Interest Rate		4.40%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Tranche G [Member] | Interest rate swap beginning December 31, 2021 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 900,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Tranche G [Member] | Interest rate swap beginning September 30, 2022 [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 400,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Unrealized (loss) gain on derivatives designated and qualifying as cash flow hedges (1) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative [Line Items]
Interest Expense	[1]	$ 2,816,000	$ 2,870,000
[1]	This component of accumulated other comprehensive loss is included in interest expense (see Note 11, “Derivatives and Hedging Activities,” for additional information).

DERIVATIVES AND HEDGING ACTIV50

DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Interest Rate Derivatives (Details) - USD ($) $ in Thousands		Jun. 30, 2018	Sep. 30, 2017
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 89,893	$ 22,139
Derivative Asset, Fair Value, Gross Liability		(17,275)	(36,801)
Derivative Asset, Collateral, Obligation to Return Cash, Offset		(11,568)	(6,330)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		11,568	6,330
Derivative Asset	[1]	78,325	15,809
Derivative Liability	[1]	(5,707)	(30,471)
Interest Rate Cap
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		31,948	12,904
Derivative Asset, Fair Value, Gross Liability		0	0
Interest Rate Swap
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		57,945	9,235
Derivative Asset, Fair Value, Gross Liability		$ (17,275)	$ (36,801)
[1]	Refer to Note 10, "Fair Value Measurements," for the condensed consolidated balance sheet classification of our interest rate swap and cap agreements.

DERIVATIVES AND HEDGING ACTIV51

DERIVATIVES AND HEDGING ACTIVITIES - Narratives (Details) - USD ($)		9 Months Ended
		Jun. 30, 2018	Jul. 01, 2017
Unrealized (loss) gain on derivatives designated and qualifying as cash flow hedges (1) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative [Line Items]
Interest Expense	[1]	$ 2,816,000	$ 2,870,000
December 30, 2017 Redesignation [Member] | Unrealized (loss) gain on derivatives designated and qualifying as cash flow hedges (1) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative [Line Items]
Interest Expense		500,000
September 30, 2016 Redesignation [Member] | Unrealized (loss) gain on derivatives designated and qualifying as cash flow hedges (1) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative [Line Items]
Interest Expense		3,000,000
March 31, 2018 Redesignation [Member] | Unrealized (loss) gain on derivatives designated and qualifying as cash flow hedges (1) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative [Line Items]
Interest Income, Other		$ 700,000
Interest Rate Swap and Cap
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimate of Time to Transfer		12 months
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred		$ (400,000)
Interest Rate Cap
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Gross Amount to be Transferred		7,900,000
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Tax to be Transferred		$ 2,200,000
Interest Rate Cap | Tranche F
Derivative [Line Items]
Derivative, Cap Interest Rate		2.50%
Interest Rate Cap | Tranche G [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 400,000,000
Interest rate swap beginning June 30, 2020 [Member] | Tranche E
Derivative [Line Items]
Derivative, Notional Amount		$ 750,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Interest rate cap beginning September 30, 2015 [Member] | Tranche E
Derivative [Line Items]
Derivative, Notional Amount		$ 750,000,000
Derivative, Cap Interest Rate		2.50%
Interest rate cap agreements beginning June 30, 2016 [Member] | Tranche F
Derivative [Line Items]
Derivative, Notional Amount		$ 400,000,000
Derivative, Cap Interest Rate		2.00%
Interest Rate Swap | Tranche F
Derivative [Line Items]
Derivative, Notional Amount		$ 1,000,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Interest Rate Swap | Tranche G [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 500,000,000
Derivative, Fixed Interest Rate		4.40%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Interest Rate Swap | March 31, 2018 Redesignation [Member]
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Gross Amount to be Transferred		$ 12,100,000
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Tax to be Transferred		2,900,000
Interest rate swap beginning September 30, 2017 [Member] | Tranche G [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 400,000,000
Derivative, Fixed Interest Rate		4.40%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Interest rate swap June 28, 2016 [Member] | Tranche F
Derivative [Line Items]
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
Interest rate swap beginning March 31, 2016 [Member] | Tranche E
Derivative [Line Items]
Derivative, Notional Amount		$ 750,000,000
Derivative, Fixed Interest Rate		0.00%
Derivative, Variable Interest Rate		0.00%
Derivative, Basis Spread on Variable Rate		0.00%
[1]	This component of accumulated other comprehensive loss is included in interest expense (see Note 11, “Derivatives and Hedging Activities,” for additional information).

SEGMENTS - Narratives (Details)

SEGMENTS - Narratives (Details)	9 Months Ended
	Jun. 30, 2018Segment
Segment Reporting [Abstract]
Number of reporting segments	3

SEGMENTS - Net Sales by Reporta

SEGMENTS - Net Sales by Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Segment Reporting Information [Line Items]
Net Sales	$ 980,662	$ 897,655	$ 2,761,692	$ 2,580,401
Operating Segments | Power & Control
Segment Reporting Information [Line Items]
Net Sales	546,905	499,069	1,558,083	1,408,853
Operating Segments | Airframe
Segment Reporting Information [Line Items]
Net Sales	398,596	362,871	1,101,771	1,072,044
Operating Segments | Non- aviation
Segment Reporting Information [Line Items]
Net Sales	$ 35,161	$ 35,715	$ 101,838	$ 99,504

SEGMENTS - EBITDA Defined by Se

SEGMENTS - EBITDA Defined by Segment to Consolidated Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
EBITDA As Defined	$ 487,141	$ 447,588	$ 1,351,797	$ 1,250,458
Interest expense - net	167,577	152,141	489,776	445,986
Stock compensation expense			36,411	32,707
Refinancing Costs	4,159	345	5,910	35,936
Income from continuing operations before income taxes	265,541	235,847	703,692	589,967
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
EBITDA As Defined	496,023	458,854	1,380,102	1,276,777
Operating Segments | Power & Control
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
EBITDA As Defined	288,202	262,855	808,539	708,601
Operating Segments | Airframe
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
EBITDA As Defined	196,746	184,091	541,171	535,600
Operating Segments | Non- aviation
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
EBITDA As Defined	11,075	11,908	30,392	32,576
Corporate, Non-Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
EBITDA As Defined	8,882	11,266	28,305	26,319
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization expense	33,925	36,367	95,534	109,076
Interest expense - net	167,577	152,141	489,776	445,986
Acquisition-related costs	10,381	4,484	16,940	30,804
Stock compensation expense	13,708	11,580	36,411	32,707
Refinancing Costs	4,159	345	5,910	35,936
Other, net	$ (8,150)	$ 6,824	$ 3,534	$ 5,982

SEGMENTS - Total Assets by Segm

SEGMENTS - Total Assets by Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 11,804,477	$ 9,975,661
Operating Segments | Power & Control
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	5,712,597	5,135,459
Operating Segments | Airframe
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	3,977,451	3,923,172
Operating Segments | Non- aviation
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	227,905	224,936
Corporate, Non-Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,886,524	614,594
Discontinued Operations, Held-for-sale [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 0	$ 77,500

ACCUMULATED OTHER COMPREHENSI56

ACCUMULATED OTHER COMPREHENSIVE LOSS - Narratives (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Loss, Derivatives Qualifying as Hedges, Tax	$ (954)	$ 5,002	$ (25,679)	$ (19,425)

ACCUMULATED OTHER COMPREHENSI57

ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Accumulated Other Comprehensive Loss (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2018USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ (85,143)
Current-period other comprehensive gain (loss)	59,387
Amounts reclassified from AOCI related to interest rate swap and cap agreements	2,039
Balance at end of period	(23,717)
Unrealized (loss) gain on derivatives designated and qualifying as cash flow hedges (1)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(26,669)	[1]
Current-period other comprehensive gain (loss)	63,742	[1]
Amounts reclassified from AOCI related to interest rate swap and cap agreements	(2,039)	[1]
Balance at end of period	39,112	[1]
Defined benefit pension plan activity
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(16,365)
Current-period other comprehensive gain (loss)	0
Amounts reclassified from AOCI related to interest rate swap and cap agreements	0
Balance at end of period	(16,365)
Currency translation adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(42,109)
Current-period other comprehensive gain (loss)	(4,355)
Amounts reclassified from AOCI related to interest rate swap and cap agreements	0
Balance at end of period	$ (46,464)
[1]	Unrealized (loss) gain represents interest rate swap and cap agreements, net of taxes of $(954) and $5,002 for the thirteen week periods ended June 30, 2018 and July 1, 2017 and $(25,679) and $(19,425) for the thirty-nine week periods ended June 30, 2018 and July 1, 2017, respectively.

ACCUMULATED OTHER COMPREHENSI58

ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Amounts Recognized in Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Deferred tax benefit from redesignated interest rate swap and cap agreements		$ 48,150	$ 66,015	$ (27,550)	$ 145,573
Unrealized (loss) gain on derivatives designated and qualifying as cash flow hedges (1) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization from redesignated interest rate swap and cap agreements (1)	[1]			2,816	2,870
Deferred tax benefit from redesignated interest rate swap and cap agreements				(777)	(1,072)
Losses reclassified into earnings, net of tax				$ 2,039	$ 1,798
[1]	This component of accumulated other comprehensive loss is included in interest expense (see Note 11, “Derivatives and Hedging Activities,” for additional information).

DISCONTINUED OPERATIONS Narrati

DISCONTINUED OPERATIONS Narrative (Details) - USD ($) $ in Thousands	Jan. 26, 2018	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Sep. 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss from discontinued operations		$ (145)	$ (779)	$ (2,943)	$ (965)
Total assets of discontinued operations		0		0		$ 77,500
Total liabilities of discontinued operations		0		0		17,304
Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss from discontinued operations		$ (145)	$ (779)	(2,943)	$ (965)
Schroth [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Divestiture, Sale Price	$ 61,400
Schroth [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business Acquisition Purchase Price Adjustment				$ 300
Goodwill, Impairment Loss						$ 32,000

DISCONTINUED OPERATIONS Schedul

DISCONTINUED OPERATIONS Schedule of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Sep. 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
NET SALES	$ 980,662	$ 897,655	$ 2,761,692	$ 2,580,401
Loss from discontinued operations	(145)	(779)	(2,943)	(965)
Trade accounts receivable - Net	658,168		658,168		$ 636,127
Inventories - Net	815,251		815,251		730,681
Prepaid expenses and other	58,610		58,610		38,683
PROPERTY, PLANT AND EQUIPMENT - NET	380,475		380,475		324,924
GOODWILL	6,209,247		6,209,247		5,745,338
OTHER INTANGIBLE ASSETS - NET	1,715,074		1,715,074		1,717,862
OTHER	114,279		114,279		53,985
Total assets of discontinued operations	0		0		77,500
Accounts payable	155,937		155,937		148,761
Accrued liabilities	285,484		285,484		335,888
DEFERRED INCOME TAXES	357,680		357,680		500,949
Total liabilities of discontinued operations	0		0		$ 17,304
Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
NET SALES	0	10,012	11,808	14,516
(Loss) Income from discontinued operations before income taxes	0	(779)	354	(965)
(Loss) Income from discontinued operations, net of tax	0	0	2,016	0
Income (loss) from discontinued operations before gain or loss on disposal net of tax	0	(779)	2,370	(965)
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	(145)	0	(5,313)	0
Loss from discontinued operations	$ (145)	$ (779)	$ (2,943)	$ (965)

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - USD ($) $ in Thousands	Jul. 13, 2018	Apr. 24, 2018	Jun. 30, 2018	Jul. 01, 2017
Subsequent Event [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired			$ 582,262	$ 135,507
Skandia [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	$ 84,000
Extant [Member]
Subsequent Event [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired		$ 532,500
Capacity [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
A/R Securitization Facility	350,000
Original Capacity [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Proceeds from Short-term Debt	300,000
A/R Securitization Facility	$ 300,000

SUPPLEMENTAL GUARANTOR INFORM62

SUPPLEMENTAL GUARANTOR INFORMATION - Supplemental Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017	Jul. 01, 2017	Sep. 30, 2016
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 1,853,373	$ 650,561	$ 970,556	$ 1,586,994
Trade accounts receivable - Net	658,168	636,127
Inventories - Net	815,251	730,681
Total assets of discontinued operations	0	77,500
Prepaid expenses and other	58,610	38,683
Total current assets	3,385,402	2,133,552
INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES	0	0
PROPERTY, PLANT AND EQUIPMENT - NET	380,475	324,924
GOODWILL	6,209,247	5,745,338
OTHER INTANGIBLE ASSETS - NET	1,715,074	1,717,862
OTHER	114,279	53,985
TOTAL ASSETS	11,804,477	9,975,661
Current portion of long-term debt	75,793	69,454
Short-term borrowings - trade receivable securitization facility	299,956	299,587
Accounts payable	155,937	148,761
Accrued liabilities	285,484	335,888
Total liabilities of discontinued operations	0	17,304
Total current liabilities	817,170	870,994
LONG-TERM DEBT	12,516,010	11,393,620
DEFERRED INCOME TAXES	357,680	500,949
OTHER NON-CURRENT LIABILITIES	212,097	161,302
Total liabilities	13,902,957	12,926,865
STOCKHOLDERS’ (DEFICIT) EQUITY	(2,098,480)	(2,951,204)
TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY	11,804,477	9,975,661
Eliminations
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Trade accounts receivable - Net	(12,236)	(41,749)
Inventories - Net	(3,057)	(2,100)
Total assets of discontinued operations		0
Prepaid expenses and other	0	0
Total current assets	(15,293)	(43,849)
INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES	(20,100,407)	(15,876,264)
PROPERTY, PLANT AND EQUIPMENT - NET	0	0
GOODWILL	0	0
OTHER INTANGIBLE ASSETS - NET	0	0
OTHER	0	0
TOTAL ASSETS	(20,115,700)	(15,920,113)
Current portion of long-term debt	0	0
Short-term borrowings - trade receivable securitization facility	0	0
Accounts payable	(12,350)	(41,566)
Accrued liabilities	0	0
Total liabilities of discontinued operations		0
Total current liabilities	(12,350)	(41,566)
LONG-TERM DEBT	0	0
DEFERRED INCOME TAXES	0	0
OTHER NON-CURRENT LIABILITIES	0	0
Total liabilities	(12,350)	(41,566)
STOCKHOLDERS’ (DEFICIT) EQUITY	(20,103,350)	(15,878,547)
TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY	(20,115,700)	(15,920,113)
TransDigm Group
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	924	2,416	776	13,560
Trade accounts receivable - Net	0	0
Inventories - Net	0	0
Total assets of discontinued operations		0
Prepaid expenses and other	0	0
Total current assets	924	2,416
INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES	(2,099,404)	(2,953,620)
PROPERTY, PLANT AND EQUIPMENT - NET	0	0
GOODWILL	0	0
OTHER INTANGIBLE ASSETS - NET	0	0
OTHER	0	0
TOTAL ASSETS	(2,098,480)	(2,951,204)
Current portion of long-term debt	0	0
Short-term borrowings - trade receivable securitization facility	0	0
Accounts payable	0	0
Accrued liabilities	0	0
Total liabilities of discontinued operations		0
Total current liabilities	0	0
LONG-TERM DEBT	0	0
DEFERRED INCOME TAXES	0	0
OTHER NON-CURRENT LIABILITIES	0	0
Total liabilities	0	0
STOCKHOLDERS’ (DEFICIT) EQUITY	(2,098,480)	(2,951,204)
TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY	(2,098,480)	(2,951,204)
TransDigm Inc.
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	1,628,948	439,473	768,641	1,421,251
Trade accounts receivable - Net	0	0
Inventories - Net	47,309	47,051
Total assets of discontinued operations		0
Prepaid expenses and other	26,406	4,746
Total current assets	1,702,663	491,270
INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES	10,325,919	10,263,999
PROPERTY, PLANT AND EQUIPMENT - NET	15,585	16,032
GOODWILL	128,764	85,905
OTHER INTANGIBLE ASSETS - NET	16,583	27,620
OTHER	79,366	20,316
TOTAL ASSETS	12,268,880	10,905,142
Current portion of long-term debt	75,793	69,454
Short-term borrowings - trade receivable securitization facility	0	0
Accounts payable	15,974	14,712
Accrued liabilities	109,607	180,916
Total liabilities of discontinued operations		0
Total current liabilities	201,374	265,082
LONG-TERM DEBT	12,024,770	11,393,620
DEFERRED INCOME TAXES	299,043	442,415
OTHER NON-CURRENT LIABILITIES	110,255	61,347
Total liabilities	12,635,442	12,162,464
STOCKHOLDERS’ (DEFICIT) EQUITY	(366,562)	(1,257,322)
TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY	12,268,880	10,905,142
TransDigm UK [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	150	0	0	0
Trade accounts receivable - Net	0	0
Inventories - Net	0	0
Total assets of discontinued operations		0
Prepaid expenses and other	0	0
Total current assets	150	0
INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES	1,096,125	0
PROPERTY, PLANT AND EQUIPMENT - NET	0	0
GOODWILL	0	0
OTHER INTANGIBLE ASSETS - NET	0	0
OTHER	0	0
TOTAL ASSETS	1,096,275	0
Current portion of long-term debt	0	0
Short-term borrowings - trade receivable securitization facility	0	0
Accounts payable	0	0
Accrued liabilities	4,679	0
Total liabilities of discontinued operations		0
Total current liabilities	4,679	0
LONG-TERM DEBT	491,240	0
DEFERRED INCOME TAXES	0	0
OTHER NON-CURRENT LIABILITIES	0	0
Total liabilities	495,919	0
STOCKHOLDERS’ (DEFICIT) EQUITY	600,356	0
TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY	1,096,275	0
Subsidiary Guarantors
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	25	(203)	5,648	8,808
Trade accounts receivable - Net	22,003	25,069
Inventories - Net	653,972	571,712
Total assets of discontinued operations		6,428
Prepaid expenses and other	21,188	24,141
Total current assets	697,188	627,147
INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES	8,600,056	7,599,210
PROPERTY, PLANT AND EQUIPMENT - NET	314,510	261,434
GOODWILL	5,419,486	4,996,034
OTHER INTANGIBLE ASSETS - NET	1,453,885	1,438,006
OTHER	29,159	27,567
TOTAL ASSETS	16,514,284	14,949,398
Current portion of long-term debt	0	0
Short-term borrowings - trade receivable securitization facility	0	0
Accounts payable	115,763	137,948
Accrued liabilities	124,531	103,902
Total liabilities of discontinued operations		0
Total current liabilities	240,294	241,850
LONG-TERM DEBT	0	0
DEFERRED INCOME TAXES	100	(99)
OTHER NON-CURRENT LIABILITIES	74,904	73,245
Total liabilities	315,298	314,996
STOCKHOLDERS’ (DEFICIT) EQUITY	16,198,986	14,634,402
TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY	16,514,284	14,949,398
Non- Guarantor Subsidiaries
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	223,326	208,875	$ 195,491	$ 143,375
Trade accounts receivable - Net	648,401	652,807
Inventories - Net	117,027	114,018
Total assets of discontinued operations		71,072
Prepaid expenses and other	11,016	9,796
Total current assets	999,770	1,056,568
INVESTMENT IN SUBSIDIARIES AND INTERCOMPANY BALANCES	2,177,711	966,675
PROPERTY, PLANT AND EQUIPMENT - NET	50,380	47,458
GOODWILL	660,997	663,399
OTHER INTANGIBLE ASSETS - NET	244,606	252,236
OTHER	5,754	6,102
TOTAL ASSETS	4,139,218	2,992,438
Current portion of long-term debt	0	0
Short-term borrowings - trade receivable securitization facility	299,956	299,587
Accounts payable	36,550	37,667
Accrued liabilities	46,667	51,070
Total liabilities of discontinued operations		17,304
Total current liabilities	383,173	405,628
LONG-TERM DEBT	0	0
DEFERRED INCOME TAXES	58,537	58,633
OTHER NON-CURRENT LIABILITIES	26,938	26,710
Total liabilities	468,648	490,971
STOCKHOLDERS’ (DEFICIT) EQUITY	3,670,570	2,501,467
TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY	$ 4,139,218	$ 2,992,438

SUPPLEMENTAL GUARANTOR INFORM63

SUPPLEMENTAL GUARANTOR INFORMATION - Supplemental Condensed Consolidating Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Condensed Income Statements, Captions [Line Items]
NET SALES	$ 980,662	$ 897,655	$ 2,761,692	$ 2,580,401
COST OF SALES	411,142	377,959	1,181,448	1,127,013
GROSS PROFIT	569,520	519,696	1,580,244	1,453,388
SELLING AND ADMINISTRATIVE EXPENSES	113,019	108,104	327,073	310,677
AMORTIZATION OF INTANGIBLE ASSETS	19,224	23,259	53,793	70,822
(LOSS) INCOME FROM OPERATIONS	437,277	388,333	1,199,378	1,071,889
INTEREST EXPENSE - NET	167,577	152,141	489,776	445,986
REFINANCING COSTS	4,159	345	5,910	35,936
EQUITY IN INCOME OF SUBSIDIARIES			0	0
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	265,541	235,847	703,692	589,967
INCOME TAX PROVISION	48,150	66,015	(27,550)	145,573
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent	217,391	169,832	731,242	444,394
Loss from discontinued operations	(145)	(779)	(2,943)	(965)
NET INCOME	217,246	169,053	728,299	443,429
OTHER COMPREHENSIVE INCOME, NET OF TAX	(30,236)	16,139	61,426	37,091
TOTAL COMPREHENSIVE INCOME	$ 187,010	$ 185,192	789,725	480,520
Eliminations
Condensed Income Statements, Captions [Line Items]
NET SALES			(60,500)	(63,969)
COST OF SALES			(60,500)	(63,044)
GROSS PROFIT			0	(925)
SELLING AND ADMINISTRATIVE EXPENSES			0	0
AMORTIZATION OF INTANGIBLE ASSETS			0	0
(LOSS) INCOME FROM OPERATIONS			0	(925)
INTEREST EXPENSE - NET			0	0
REFINANCING COSTS			0	0
EQUITY IN INCOME OF SUBSIDIARIES			1,641,822	1,427,977
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES			(1,641,822)	(1,428,902)
INCOME TAX PROVISION			0	0
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent			(1,641,822)	(1,428,902)
Loss from discontinued operations			0	0
NET INCOME			(1,641,822)	(1,428,902)
OTHER COMPREHENSIVE INCOME, NET OF TAX			(59,910)	(56,307)
TOTAL COMPREHENSIVE INCOME			(1,701,732)	(1,485,209)
TransDigm Group
Condensed Income Statements, Captions [Line Items]
NET SALES			0	0
COST OF SALES			0	0
GROSS PROFIT			0	0
SELLING AND ADMINISTRATIVE EXPENSES			0	69
AMORTIZATION OF INTANGIBLE ASSETS			0	0
(LOSS) INCOME FROM OPERATIONS			0	(69)
INTEREST EXPENSE - NET			0	0
REFINANCING COSTS			0	0
EQUITY IN INCOME OF SUBSIDIARIES			(728,299)	(443,498)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES			728,299	443,429
INCOME TAX PROVISION			0	0
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent			728,299	443,429
Loss from discontinued operations			0	0
NET INCOME			728,299	443,429
OTHER COMPREHENSIVE INCOME, NET OF TAX			61,426	37,091
TOTAL COMPREHENSIVE INCOME			789,725	480,520
TransDigm Inc.
Condensed Income Statements, Captions [Line Items]
NET SALES			118,783	102,467
COST OF SALES			68,022	56,826
GROSS PROFIT			50,761	45,641
SELLING AND ADMINISTRATIVE EXPENSES			74,708	73,480
AMORTIZATION OF INTANGIBLE ASSETS			1,038	635
(LOSS) INCOME FROM OPERATIONS			(24,985)	(28,474)
INTEREST EXPENSE - NET			478,341	452,867
REFINANCING COSTS			5,839	35,936
EQUITY IN INCOME OF SUBSIDIARIES			(913,523)	(984,479)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES			404,358	467,202
INCOME TAX PROVISION			(323,941)	23,704
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent			728,299	443,498
Loss from discontinued operations			0	0
NET INCOME			728,299	443,498
OTHER COMPREHENSIVE INCOME, NET OF TAX			66,480	32,569
TOTAL COMPREHENSIVE INCOME			794,779	476,067
TransDigm UK [Member]
Condensed Income Statements, Captions [Line Items]
NET SALES			0	0
COST OF SALES			0	0
GROSS PROFIT			0	0
SELLING AND ADMINISTRATIVE EXPENSES			0	0
AMORTIZATION OF INTANGIBLE ASSETS			0	0
(LOSS) INCOME FROM OPERATIONS			0	0
INTEREST EXPENSE - NET			2,569	0
REFINANCING COSTS			71	0
EQUITY IN INCOME OF SUBSIDIARIES			0	0
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES			(2,640)	0
INCOME TAX PROVISION			0	0
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent			(2,640)	0
Loss from discontinued operations			0	0
NET INCOME			(2,640)	0
OTHER COMPREHENSIVE INCOME, NET OF TAX			0	0
TOTAL COMPREHENSIVE INCOME			(2,640)	0
Subsidiary Guarantors
Condensed Income Statements, Captions [Line Items]
NET SALES			2,243,838	2,161,060
COST OF SALES			895,381	897,838
GROSS PROFIT			1,348,457	1,263,222
SELLING AND ADMINISTRATIVE EXPENSES			198,652	195,700
AMORTIZATION OF INTANGIBLE ASSETS			46,533	64,072
(LOSS) INCOME FROM OPERATIONS			1,103,272	1,003,450
INTEREST EXPENSE - NET			(4)	(816)
REFINANCING COSTS			0	0
EQUITY IN INCOME OF SUBSIDIARIES			0	0
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES			1,103,276	1,004,266
INCOME TAX PROVISION			283,975	116,846
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent			819,301	887,420
Loss from discontinued operations			(2,310)	(782)
NET INCOME			816,991	886,638
OTHER COMPREHENSIVE INCOME, NET OF TAX			8,553	16,985
TOTAL COMPREHENSIVE INCOME			825,544	903,623
Non- Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
NET SALES			459,571	380,843
COST OF SALES			278,545	235,393
GROSS PROFIT			181,026	145,450
SELLING AND ADMINISTRATIVE EXPENSES			53,713	41,428
AMORTIZATION OF INTANGIBLE ASSETS			6,222	6,115
(LOSS) INCOME FROM OPERATIONS			121,091	97,907
INTEREST EXPENSE - NET			8,870	(6,065)
REFINANCING COSTS			0	0
EQUITY IN INCOME OF SUBSIDIARIES			0	0
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES			112,221	103,972
INCOME TAX PROVISION			12,416	5,023
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent			99,805	98,949
Loss from discontinued operations			(633)	(183)
NET INCOME			99,172	98,766
OTHER COMPREHENSIVE INCOME, NET OF TAX			(15,123)	6,753
TOTAL COMPREHENSIVE INCOME			$ 84,049	$ 105,519

SUPPLEMENTAL GUARANTOR INFORM64

SUPPLEMENTAL GUARANTOR INFORMATION - Supplemental Condensed Consolidating Cash Flow Statement (Details) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Condensed Cash Flow Statements, Captions [Line Items]
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	$ 690,910	$ 555,216
Capital expenditures	(50,097)	(55,671)
Payments made in connection with acquisitions	(582,262)	(135,507)
Proceeds (payments made) from sale (purchase) of discontinued operations	57,686	(79,695)
Net cash used in investing activities	(574,673)	(270,873)
Intercompany activities	0	0
Proceeds from exercise of stock options	40,621	18,046
Special dividend and dividend equivalent payments	(56,148)	(1,376,034)
Treasury stock purchased	0	(389,821)
Proceeds from term loans, net	12,779,772	1,132,755
Repayments on term loans	(12,155,198)	(48,453)
Proceeds from senior subordinated notes	490,411	0
Cash tender and redemption of the 2021 Notes, including premium	0	528,847
Proceeds from additional 2025 Notes offering, net	0	300,517
Other	(9,904)	(10,777)
Net cash (used in) provided by financing activities	1,089,554	(902,614)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	(2,979)	1,833
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	1,202,812	(616,438)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	650,561	1,586,994
CASH AND CASH EQUIVALENTS, END OF PERIOD	1,853,373	970,556
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	0	695
Capital expenditures	0	0
Payments made in connection with acquisitions	0	0
Proceeds (payments made) from sale (purchase) of discontinued operations	0	0
Net cash used in investing activities	0	0
Intercompany activities	0	(695)
Proceeds from exercise of stock options	0	0
Special dividend and dividend equivalent payments	0	0
Treasury stock purchased		0
Proceeds from term loans, net	0	0
Repayments on term loans	0	0
Proceeds from senior subordinated notes	0
Cash tender and redemption of the 2021 Notes, including premium		0
Proceeds from additional 2025 Notes offering, net		0
Other	0	0
Net cash (used in) provided by financing activities	0	(695)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	0	0
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	0	0
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	0	0
CASH AND CASH EQUIVALENTS, END OF PERIOD	0	0
TransDigm Group
Condensed Cash Flow Statements, Captions [Line Items]
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	0	(69)
Capital expenditures	0	0
Payments made in connection with acquisitions	0	0
Proceeds (payments made) from sale (purchase) of discontinued operations	0	0
Net cash used in investing activities	0	0
Intercompany activities	14,035	1,735,094
Proceeds from exercise of stock options	40,621	18,046
Special dividend and dividend equivalent payments	(56,148)	(1,376,034)
Treasury stock purchased		(389,821)
Proceeds from term loans, net	0	0
Repayments on term loans	0	0
Proceeds from senior subordinated notes	0
Cash tender and redemption of the 2021 Notes, including premium		0
Proceeds from additional 2025 Notes offering, net		0
Other	0	0
Net cash (used in) provided by financing activities	(1,492)	(12,715)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	0	0
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(1,492)	(12,784)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	2,416	13,560
CASH AND CASH EQUIVALENTS, END OF PERIOD	924	776
TransDigm Inc.
Condensed Cash Flow Statements, Captions [Line Items]
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	(291,416)	(529,423)
Capital expenditures	(1,372)	(1,479)
Payments made in connection with acquisitions	(582,262)	(135,507)
Proceeds (payments made) from sale (purchase) of discontinued operations	57,686	(79,695)
Net cash used in investing activities	(525,948)	(216,681)
Intercompany activities	1,392,169	(751,701)
Proceeds from exercise of stock options	0	0
Special dividend and dividend equivalent payments	0	0
Treasury stock purchased		0
Proceeds from term loans, net	12,779,772	1,132,755
Repayments on term loans	12,155,198	(48,453)
Proceeds from senior subordinated notes	0
Cash tender and redemption of the 2021 Notes, including premium		528,847
Proceeds from additional 2025 Notes offering, net		300,517
Other	(9,904)	(10,777)
Net cash (used in) provided by financing activities	2,006,839	93,494
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	0	0
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	1,189,475	(652,610)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	439,473	1,421,251
CASH AND CASH EQUIVALENTS, END OF PERIOD	1,628,948	768,641
TransDigm UK [Member]
Condensed Cash Flow Statements, Captions [Line Items]
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	2,110	0
Capital expenditures	0	0
Payments made in connection with acquisitions	0	0
Proceeds (payments made) from sale (purchase) of discontinued operations	0	0
Net cash used in investing activities	0	0
Intercompany activities	(492,371)	0
Proceeds from exercise of stock options	0	0
Special dividend and dividend equivalent payments	0	0
Treasury stock purchased		0
Proceeds from term loans, net	0	0
Repayments on term loans	0	0
Proceeds from senior subordinated notes	490,411
Cash tender and redemption of the 2021 Notes, including premium		0
Proceeds from additional 2025 Notes offering, net		0
Other	0	0
Net cash (used in) provided by financing activities	(1,960)	0
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	0	0
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	150	0
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	0	0
CASH AND CASH EQUIVALENTS, END OF PERIOD	150	0
Subsidiary Guarantors
Condensed Cash Flow Statements, Captions [Line Items]
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	863,173	1,111,978
Capital expenditures	(41,999)	(50,480)
Payments made in connection with acquisitions	0	0
Proceeds (payments made) from sale (purchase) of discontinued operations	0	0
Net cash used in investing activities	(41,999)	(50,480)
Intercompany activities	(820,946)	(1,064,658)
Proceeds from exercise of stock options	0	0
Special dividend and dividend equivalent payments	0	0
Treasury stock purchased		0
Proceeds from term loans, net	0	0
Repayments on term loans	0	0
Proceeds from senior subordinated notes	0
Cash tender and redemption of the 2021 Notes, including premium		0
Proceeds from additional 2025 Notes offering, net		0
Other	0	0
Net cash (used in) provided by financing activities	(820,946)	(1,064,658)
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	0	0
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	228	(3,160)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	(203)	8,808
CASH AND CASH EQUIVALENTS, END OF PERIOD	25	5,648
Non- Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	117,043	(27,965)
Capital expenditures	(6,726)	(3,712)
Payments made in connection with acquisitions	0	0
Proceeds (payments made) from sale (purchase) of discontinued operations	0	0
Net cash used in investing activities	(6,726)	(3,712)
Intercompany activities	(92,887)	81,960
Proceeds from exercise of stock options	0	0
Special dividend and dividend equivalent payments	0	0
Treasury stock purchased		0
Proceeds from term loans, net	0	0
Repayments on term loans	0	0
Proceeds from senior subordinated notes	0
Cash tender and redemption of the 2021 Notes, including premium		0
Proceeds from additional 2025 Notes offering, net		0
Other	0	0
Net cash (used in) provided by financing activities	(92,887)	81,960
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	(2,979)	1,833
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	14,451	52,116
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	208,875	143,375
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 223,326	$ 195,491

SUPPLEMENTAL GUARANTOR INFORM65

SUPPLEMENTAL GUARANTOR INFORMATION Narrative (Details)	Jun. 30, 2018
Condensed Financial Statements, Captions [Line Items]
Percentage of ownership in subsidiary	100.00%