<SEC-DOCUMENT>0001126328-18-000092-index.html : 20180215
<SEC-HEADER>0001126328-18-000092.hdr.sgml : 20180215
<ACCEPTANCE-DATETIME>20180214182319
ACCESSION NUMBER:		0001126328-18-000092
CONFORMED SUBMISSION TYPE:	SC 13G
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20180215
DATE AS OF CHANGE:		20180214

SUBJECT COMPANY:	

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

	FILING VALUES:
		FORM TYPE:		SC 13G
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-81705
		FILM NUMBER:		18615201

	BUSINESS ADDRESS:	
		STREET 1:		1301 EAST 9TH STREET
		STREET 2:		SUITE 3000
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44114
		BUSINESS PHONE:		216 706 2960

	MAIL ADDRESS:	
		STREET 1:		1301 EAST 9TH STREET
		STREET 2:		SUITE 3000
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44114

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TD HOLDING CORP
		DATE OF NAME CHANGE:	20030818

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRINCIPAL GLOBAL INVESTORS
		CENTRAL INDEX KEY:			0000769734
		IRS NUMBER:				421482034

	FILING VALUES:
		FORM TYPE:		SC 13G

	BUSINESS ADDRESS:	
		STREET 1:		711 HIGH STREET
		CITY:			DES MOINES
		STATE:			IA
		ZIP:			50392-0300
		BUSINESS PHONE:		5152475111

	MAIL ADDRESS:	
		STREET 1:		711 HIGH STREET
		CITY:			DES MOINES
		STATE:			IA
		ZIP:			50392-0300

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INVISTA CAPITAL MANAGEMENT LLC /IA/
		DATE OF NAME CHANGE:	19990512

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INVISTA CAPITAL MANAGEMENT INC/IA/
		DATE OF NAME CHANGE:	19970211

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	VALUE INVESTORS INC
		DATE OF NAME CHANGE:	19880526
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G
<SEQUENCE>1
<FILENAME>TransDigmGroup_New_20171231.txt
<TEXT>
Document 1 - file: TransDigmGroup_New_20171231.txt

</DOCUMENT>
</SEC-DOCUMENT>