September 26, 2016 Esterline Technologies Corporation Bellevue, Washington 98004 Ladies and Gentlemen:

Exhibit 99.1

September 26, 2016

Xxxxxxxxx Technologies Corporation

000 000^xx Xxxxxx X.X.

Xxxxxxxx, Xxxxxxxxxx 00000

Ladies and Gentlemen:

This letter sets forth the amendment number one to that certain letter agreement (the “Agreement”) between Xxxxxxxxx Technologies Corporation (the “Company”), on the one hand, and the entities and natural persons set forth in the Exhibit A attached thereto (collectively “FPA”), on the other hand, dated as of September 16, 2016.

1. Amendment. Section 1 of the Agreement is hereby revised in its entirety to read:

The Company and FPA acknowledge that the parties are in discussions regarding certain matters relating to FPA’s level of ownership of shares of the Company’s outstanding common stock (the “Common Stock”), and certain other governance matters (the “Discussions”). This Agreement confirms that FPA will not purchase or acquire, directly or indirectly, any additional shares of Common Stock until the earlier of (i) October 12, 2016; or (ii) seventy-two (72) hours after FPA provides notice that the Discussions have terminated (the “Standstill Period”). Any such written notice should be sent to xxxxxx.xxxxx@xxxxxxxxx.xxx with a copy to xxxxx.xxxxxxxx@xxxxxxx.xxx.

2. All other terms and provisions of the Agreement remain in place.

Very truly yours,
Xxxxxxxxx Technologies Corporation
By:		/s/ Xxxxxx X. Xxxxxxx
		Name:		Xxxxxx X. Xxxxxxx
		Title:		President & CEO

Dated: September 27, 2016

Confirmed and Agreed to as of September 27, 2016
First Pacific Advisors, LLC
By:		/s/ Xxxxx X. Xxxxxx
		Name:		Xxxxx X. Xxxxxx
		Title:		Managing Director, General Counsel

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