<SEC-DOCUMENT>0000919574-26-001436.txt : 20260227
<SEC-HEADER>0000919574-26-001436.hdr.sgml : 20260227
<ACCEPTANCE-DATETIME>20260227162259
ACCESSION NUMBER:		0000919574-26-001436
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20260225
FILED AS OF DATE:		20260227
DATE AS OF CHANGE:		20260227

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SMALL ROBERT J
		CENTRAL INDEX KEY:			0001234544
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32833
		FILM NUMBER:		26700352

	MAIL ADDRESS:	
		STREET 1:		C/O BERKSHIRE PARTNERS LLC
		STREET 2:		200 CLARENDON STREET, 35TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TransDigm Group INC
		CENTRAL INDEX KEY:			0001260221
		STANDARD INDUSTRIAL CLASSIFICATION:	AIRCRAFT PART & AUXILIARY EQUIPMENT, NEC [3728]
		ORGANIZATION NAME:           	04 Manufacturing
		EIN:				510484716
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		1350 EUCLID AVENUE
		STREET 2:		SUITE 1600
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44115
		BUSINESS PHONE:		216 706 2960

	MAIL ADDRESS:	
		STREET 1:		1350 EUCLID AVENUE
		STREET 2:		SUITE 1600
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44115

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TD HOLDING CORP
		DATE OF NAME CHANGE:	20030818
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ownership.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-02-25</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001260221</issuerCik>
        <issuerName>TransDigm Group INC</issuerName>
        <issuerTradingSymbol>TDG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001234544</rptOwnerCik>
            <rptOwnerName>SMALL ROBERT J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BERKSHIRE PARTNERS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON STREET, 35TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-02-25</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1285</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>366142</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Stockbridge Fund, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>68139</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Stockbridge Partners LLC</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60246</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Family Trusts</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5625</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The purchase of the Issuer's common stock reported herein was matchable under Section 16(b) of the Securities Exchange Act of 1934, to the extent of one (1) share, with the sale of one (1) share of the Issuer's common stock at a price of $1,335.72 per share by an entity in which the Reporting Person has a pecuniary interest. The Reporting Person has paid to the Issuer an amount representing the difference between the purchase and sale prices of the two transactions with respect to such one share of the Issuer's common stock.</footnote>
        <footnote id="F2">Represents shares held by Stockbridge Fund, L.P. (&quot;SF&quot;). Berkshire Partners Holdings LLC (&quot;BPH&quot;) is the general partner of BPSP, L.P. (&quot;BPSP&quot;), which is the managing member of SP, the registered investment adviser to SF. Stockbridge Associates LLC (&quot;SA&quot;) is the general partner of SF. The Reporting Person is a managing member of each of BPH, BPSP, SP and SA. As such, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares of the Issuer's common stock held by SF. However, the Reporting Person disclaims beneficial ownership of these shares, except to the extent, if any, of his pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purposes.</footnote>
        <footnote id="F3">Represents shares held by Stockbridge Partners LLC (&quot;SP&quot;) on behalf of a managed account over which it has shared voting and sole dispositive power. This Form 4 has been filed because the Reporting Person is a director of the Issuer and a managing member of SP. As such, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares of the Issuer's common stock held by SP. However, the Reporting Person disclaims beneficial ownership of these shares, except to the extent, if any, of his pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purposes.</footnote>
        <footnote id="F4">Represents shares of Common Stock beneficially owned by certain family trusts. The Reporting Person's immediate family members are beneficiaries of such family trusts.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Robert J. Small</signatureName>
        <signatureDate>2026-02-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
