Exhibit 99.1

EXECUTION COPY

Esterline Technologies Corporation

500 108th Avenue NE

Bellevue, Washington 98004

December 13, 2012

Relational Investors LLC

12400 High Bluff Drive, Suite 600

San Diego, CA 92130

Gentlemen:

This letter constitutes the agreement (the “Agreement”) between Esterline Technologies Corporation (the “Company”), on the one hand, and Relational Investors LLC (“Relational”) and each of the other Persons (as defined below) set forth on the signature pages hereto (the “Relational Affiliates,” and together with Relational, the Relational Affiliates and the affiliates of each of the foregoing, the “Relational Group”), on the other hand, with respect to the matters set forth below:

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If to the Company:

Esterline Technologies Corporation

500 108th Avenue N.E.

Bellevue, Washington 98004

With a copy (which shall not constitute notice) to:

Skadden, Arps, Slate, Meagher & Flom LLP

300 South Grand Avenue, Suite 3400

Los Angeles, CA 90071

If to the Relational Group:

Relational Investors LLC

12400 High Bluff Drive, Suite 600

San Diego, CA 92130

Attn: Kathleen Carney

Phone: (858) 704-3423

Fax: (858) 704 - 3347

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[Execution page follows.]

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Confirmed and agreed to as of

the date first written above:

[Signature Page to Letter Agreement]

[Signature Page to Letter Agreement]

[Signature Page to Letter Agreement]

EXHIBIT A

Form 8-K Information

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On December 13, 2012, the Board of Directors (the “Board”) of Esterline Technologies Corporation (“Esterline”) increased the size of the Board from nine (9) to eleven (11) directors and elected Scott E. Kuechle and Henry W. (Jay) Winship to serve as directors of Esterline effective immediately. Mr. Kuechle was classified into the class of directors whose term expires at the 2013 annual stockholders meeting, and Mr. Winship was classified into the class of directors whose term expires at the 2014 annual stockholders meeting. In light of the foregoing classification, the Board nominated Mr. Kuechle, together with the other directors whose terms expire at the 2013 annual stockholders meeting, Paul V. Haack and R. Bradley Lawrence, for election as directors at Esterline’s 2013 annual stockholders meeting for a term expiring at the 2016 annual stockholders meeting. Mr. Winship also was appointed to the Compensation Committee and Strategy & Technology Committee of the Board. Consistent with its customary practice, the Board will consider and potentially make additional changes to the composition of Esterline’s Board Committees at its regular meeting following the 2013 annual stockholders meeting.

For their services as non-employee directors, Messrs. Kuechle and Winship will be entitled to receive the standard compensation for non-employee directors of Esterline. Esterline will also reimburse Messrs. Kuechle and Winship for out-of-pocket expenses incurred in connection with attendance or participation at meetings. The non-employee director compensation program is described in further detail in Esterline’s proxy statement for its 2012 Annual Meeting filed with the Securities and Exchange Commission on January 26, 2012.

Also on December 13, 2012, Esterline entered into a letter agreement (the “Letter Agreement”) with Relational Investors LLC (“Relational”) and certain affiliates of Relational, including Mr. Winship (collectively, the “Relational Group”), pursuant to which Mr. Winship was elected to the Board and appointed to the Compensation Committee and Strategy & Technology Committee of the Board. Pursuant to the terms of the Letter Agreement, the Board has the discretion to nominate Mr. Winship for election by Esterline’s stockholders at the 2014 annual stockholders meeting. During the term of the Letter Agreement, Relational and its affiliates will vote in favor of the election of each nominee to the Board that has been nominated by the Board and, with respect to other matters subject to a stockholder vote, either (i) abstain from voting its Voting Securities (as defined in the Letter Agreement) of Esterline, (ii) vote in favor of the matter or (iii) vote in accordance with the Board’s recommendation on the matter.

The Letter Agreement also contains customary standstill provisions, including, among others, that no member of the Relational Group will: (a) make, participate in or encourage a solicitation of proxies; (b) initiate, propose or otherwise solicit any stockholder proposals; (c) seek election or appointment to, or representation on, or nominate or propose the nomination of any candidate to, the Board (other than Mr. Winship), or seek the removal of any member of the Board; (d) act alone or in concert with others to control or influence or seek to control or influence the management, Board or policies of Esterline; (e) participate in, or take any action

pursuant to, any “stockholder access” proposal; (f) own or seek to own more than 9.9% of the outstanding Voting Securities of Esterline; (g) make any public statement or public disclosure regarding any intent, purpose, plan or proposal relating to the Board, Esterline, its management, affairs or policies or any of Esterline’s securities or assets; or (h) seek, propose or make any statement with respect to any merger, consolidation, business combination, tender or exchange offer, sale or purchase of assets or other extraordinary transaction involving Esterline. The Letter Agreement will terminate on the earlier of (x) if Esterline does not nominate Mr. Winship for election as a director at the 2014 annual stockholders meeting, the 60^th day prior to the last day of the advance notice period for the 2014 annual stockholders meeting and (y) the earlier of (A) the 45^th day after the first day on which Mr. Winship is no longer a member of the Board and (B) the 60^th day prior to the last day of the advance notice period for the 2017 annual stockholders meeting. In addition, Mr. Winship agreed to tender his resignation from the Board within five (5) business days of the Relational Group holding less than 2% of Esterline’s outstanding common stock or a breach of the Letter Agreement by a member of Relational Group, including Mr. Winship.

A copy of the Letter Agreement is attached hereto as Exhibit 99.1 and incorporated herein by reference. There was no arrangement or understanding between Mr. Kuechle and any other person pursuant to which he was elected to the director position.

A copy of the press release announcing the election of Messrs. Kuechle and Winship to the Board is attached hereto as Exhibit 99.2 and incorporated herein by reference.

EXHIBIT B

Press Release

[see attached]

ESTERLINE CORPORATION APPOINTS SCOTT E. KUECHLE AND H. JAY WINSHIP TO BOARD OF DIRECTORS

Expands Board from Nine to Eleven Directors

BELLEVUE, Wash., December 18, 2012 – Esterline Corporation (NYSE:ESL) (www.esterline.com), a leading specialty manufacturer serving the global aerospace and defense markets, today announced the appointment of Scott E. Kuechle, former Executive Vice President and Chief Financial Officer of Goodrich Corporation, and H. Jay Winship, a Principal and Senior Managing Director of Relational Investors LLC (“Relational”), to the company’s Board of Directors effective December 13.

Kuechle was appointed to the class of directors whose term of office will expire at the 2013 annual meeting, when he will be nominated for election to a three-year term. Winship was appointed to the class of directors whose term of office will expire at the 2014 annual meeting. With these additions, Esterline’s Board now consists of eleven directors as a transition measure, anticipating Robert W. Cremin’s retirement in March. Nine of the directors meet New York Stock Exchange standards for independence: the other two directors are Brad Lawrence, the company’s Chairman, President & CEO; and his predecessor, Mr. Cremin.

Lawrence commented, “We are pleased to welcome Scott and Jay to our Board, and look forward to their insights and contributions. Scott’s extensive background in the aerospace and defense industry will be valuable to our Board as we continue to build on Esterline’s reputation for excellence in the development, manufacture, and service of highly engineered solutions for our customers. Jay will bring the perspective of a large shareholder as well as additional financial acumen to the boardroom, and we look forward to benefitting from his perspective and expertise.”

Kuechle said, “I am excited to join the Esterline Board at this important time. Esterline is an outstanding company with a very bright future ahead, and I am pleased to be part of it.”

“We invested in Esterline because of its strong strategic position and experienced management team,” Winship added. “We believe the company has excellent opportunities to create value, and I look forward to working with the management team and the board.”

Under the terms of an agreement between Esterline and Relational, Relational will support the Esterline Board and has agreed to customary standstill provisions during the term of the agreement. Subject to certain conditions, the agreement runs into 2016, as long as Relational holds 2% or more of Esterline’s total common stock outstanding and Mr. Winship continues to serve on the Board. A copy of the agreement with further detail is attached to a Form 8-K filed by Esterline today with the Securities and Exchange Commission.

About Scott Kuechle:

Mr. Kuechle is recently retired from a 29-year career at Goodrich Corporation — a global supplier of systems and services to the aerospace and defense markets — which was acquired by United Technologies in July 2012. He served in a variety of increasingly responsible financial management positions at Goodrich, including Treasurer and Corporate Controller, concluding with seven years as Chief Financial Officer. In addition to his new role with Esterline, Mr. Kuechle also serves on the Board of Directors of Wesco Aircraft, and is a former member of Standard & Poor’s Corporate Executive Council.

Mr. Kuechle received his undergraduate degree in business administration and economics, magna cum laude, from the University of Wisconsin-Eau Claire, and also earned a master’s degree in industrial administration with a concentration in finance from Carnegie Mellon University, graduating first in his class.

About Jay Winship:

Mr. Winship is a Principal and Senior Managing Director for Relational Investors LLC and has been with the firm since its inception in 1996. As such, he works with Relational’s Investment Committee to develop and execute Relational’s investment strategies. Mr. Winship formerly served on the boards of Del Mar Database, Seaspan Containers Lines, Ltd., Seaspan Ship Management, Ltd., McKay Creek Technologies, Ltd, and Excel National Bank.

A magna cum laude graduate from the University of Arizona, Mr. Winship holds a bachelor’s degree in finance and a master’s in business administration from the University of California, Los Angeles. He is a Certified Public Accountant and holds the professional designation of Chartered Financial Analyst.

About Esterline:

Esterline Corporation is a leading worldwide supplier to the aerospace and defense industry specializing in three core areas: Advanced Materials; Avionics & Controls; and Sensors & Systems. With annual sales of approximately $2 billion, Esterline employs roughly 12,000 people worldwide.

Operations within the Advanced Materials segment focus on technologies including high-temperature-resistant materials and components used for a wide range of military and commercial aerospace purposes, and combustible ordnance and electronic warfare countermeasure products.

Operations within the Avionics & Controls segment focus on technology interface systems for commercial and military aircraft and similar devices for land- and sea-based military vehicles, cockpit integration systems, secure communications systems, specialized medical equipment, and other high-end industrial applications.

The Sensors & Systems segment includes operations that produce high-precision temperature and pressure sensors, specialized harsh-environment connectors, electrical power distribution equipment, and other related systems principally for aerospace and defense customers.