<SEC-DOCUMENT>0000919574-25-005699.txt : 20250916
<SEC-HEADER>0000919574-25-005699.hdr.sgml : 20250916
<ACCEPTANCE-DATETIME>20250916181724
ACCESSION NUMBER:		0000919574-25-005699
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250912
FILED AS OF DATE:		20250916
DATE AS OF CHANGE:		20250916

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:		251318332

	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>
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    <periodOfReport>2025-09-12</periodOfReport>

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        <issuerName>TransDigm Group INC</issuerName>
        <issuerTradingSymbol>TDG</issuerTradingSymbol>
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        </reportingOwnerId>
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            <rptOwnerStreet2>200 CLARENDON STREET, 35TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
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            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
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            <otherText></otherText>
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                <directOrIndirectOwnership>
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                <directOrIndirectOwnership>
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                <transactionFormType>4</transactionFormType>
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            <transactionTimeliness></transactionTimeliness>
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                <transactionShares>
                    <value>10000</value>
                </transactionShares>
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                    <value>0</value>
                    <footnoteId id="F18"/>
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                <sharesOwnedFollowingTransaction>
                    <value>5581</value>
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    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">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="F2">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="F3">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>
        <footnote id="F4">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1270.8479 to $1271.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F5">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1271.8479 to $1272.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F6">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1272.8479 to $1273.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F7">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1273.8479 to $1274.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F8">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1274.8479 to $1275.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F9">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1275.8479 to $1276.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F10">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1276.8479 to $1277.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F11">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1277.8479 to $1278.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F12">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1278.8479 to $1279.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F13">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1279.8479 to $1280.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F14">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1280.8479 to $1281.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F15">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1281.8479 to $1282.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F16">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1282.8479 to $1283.8478. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F17">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions within the range of $1283.8479 to $1284.3525. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F18">Represents shares of Common Stock that were disposed of by the Reporting Person pursuant to a gift to a donor advised fund for no consideration.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Robert J. Small</signatureName>
        <signatureDate>2025-09-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
