Your vote is important. Whether or not you plan to attend the annual meeting, please vote on the Internet,internet, by phone, or by completing and returning the enclosed proxy card.

By order of the Board of Directors,

Halle Martin

Secretary

June 1, 2022

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE STOCKHOLDERS MEETING TO BE HELD ON JULY 12, 2022.

The Proxy Statement

TransDigm’s Board consists of a standing Audit Committee, Compensation Committee, Nominating and Corporate Governance Committee, and Executive Committee. The Chairman, which is separate from the CEO role, oversees the Chief Executive Officer and other senior management in the competent and ethical operation of TransDigm and ensures that the long-term interests of stockholders are being served. To satisfy the Board’s duties, directors are expected to take a proactive approach to their positionsBoard to ensure that TransDigmit is committed to business successfunctioning effectively and high standards of responsibility and ethics.

TransDigm’s key governance documents, including our Corporate Governance Guidelines, are available at www.transdigm.com/investor-relations/corporate-governance. The Board met seven times during 2021. In fiscal 2021, independent directors met in executive session after each regularly scheduled Board meeting. Each member ofserving the Board who served during 2021 attended or participated in 75% or more of the aggregate of the total number of meetings of the Board and each committee of the Board on which such member served during 2021, except that Mr. Dunn attended less than 75% of the meetings. Mr. Dunn missed one Board meeting and two committee meetings as a result of a medical emergency that occurred on the date of the committee meetings and after he had already traveled to Cleveland for the meetings; he was still in the hospital for the Board meeting the following day. In addition, Mr. Dunn missed two telephonic meetings relating to TransDigm’s potential acquisition of Meggitt plc that were called on short notice.

The Board does not hold a meeting on the dateinterests of our annual stockholder meeting and we have not established a policy regarding director attendance at the stockholder meeting. Two directors attended the 2021 annual stockholder meeting.

Composition of the Board and its Committees

shareholders. The Board believes that its current leadership structure, in which the roles of Chairman and CEO are separated, best serves the Board’s ability to carry out its roles and responsibilities on behalf of TransDigm’s stockholders,shareholders, including its oversight of management. The Board also believes that the currentthis structure allows our CEO to focus on managingdrive the performance and strategic vision of TransDigm, while leveraging our Chairman’s experience with respect to capital allocation, acquisitions and the strategic vision and culture of TransDigm andability to drive accountability at the Board level. In 2023, TransDigm also added the role of LID to further foster the role of independent directors on the Board and strengthen the Board’s alignment with its shareholders.

The Board has determined that all Board members, other than Messrs. Stein, Howley, and Howley,Valladares, are independent under applicable rules of the New York Stock Exchange (“NYSE”).

The Board also determined that Messrs. Staer and Dunn, who retired from the Board in October 2023, were independent under the applicable rules of the NYSE.

The LID functions as an important conduit for communications between the independent directors and TransDigm’s management. The LID role is designed to help ensure that the interests of TransDigm’s shareholders are being served. Since late 2023, Mr. Small has served as the LID. In furtherance of these goals, the LID has the following roles and responsibilities:

TransDigm’s governance framework is designed to foster principled actions, informed and effective decision-making, and appropriate monitoring of compliance and performance.

The Board believes that evaluating the executive team’s management of the risks confronting TransDigm is one of its most important areas of oversight. In carrying out this responsibility, the Board is assisted by each of its committees that considers risks within its areas of responsibility and apprises the full Board of any significant risks and management’s response to those risks. The Board has retained primary oversight of certain areas of risk and management’s response, including corporate strategy. While the Board and its committees exercise oversight of risk management, management is responsible for implementing and supervising day-to-day risk management processes and reporting to the Board and its committees.

The Compensation Committee has primary responsibility to oversee risks related to our compensation programs. In establishing and reviewing our compensation programs, the Compensation Committee evaluatedevaluates whether the design and operation of our compensation programs orand policies encourage our executive officers or our other employees to take unnecessary or excessive risks. The Compensation Committee concluded that TransDigm’s compensation programs and policies provide an effective and appropriate mix of incentives to help ensure performance is focused on long-term stockholdershareholder value creation and do not encourage short-term risk taking at the expense of long-term results or create risks that are reasonably likely to have a material adverse effect on TransDigm.

The Board conducts an annual self-evaluation that is intendeddesigned to determine whetherevaluate the performance of the Board. In particular, the self-evaluation is designed to obtain feedback on topics such as board composition, effectiveness of communication, and accountability to TransDigm’s shareholders. In addition, the assessment seeks feedback on potential opportunities to enhance the effectiveness of the Board, including content to include in Board meetings and continued education. The results of the self-assessment are shared with the Board and its committees are functioning effectively. considered for implementation.

In addition, each of the Audit, Compensation, and Nominating &and Corporate Governance Committees conducts its own annual self-evaluation and reports the results to the Board. Discussion topics include, among others, Board and committee composition and leadership, meeting effectiveness, appropriateness of agenda topics and information, access to management and outside auditors, and succession planning.

We have a Code of Business Conduct and Ethics that reflects TransDigm’s commitment to honesty, integrity, and the ethical behavior of our employees, officers, directors, and directors.agents. The Code of Business Conduct and Ethics governs the actions, interactions, and working relationships of our employees, officers, directors, and directorsagents with customers, fellow employees, competitors, government, and self-regulatory agencies, investors, the public, the media, and anyone else with whom we have contact. The Code of Business Conduct and Ethics sets forth the expectation that employees, officers, directors, and directorsagents will conduct business legally and addresses conflict of interest situations, international trade compliance, protection and use of TransDigm assets, corporate opportunities, fair dealing, confidentiality, human rights, and reporting of illegal or unethical behavior. The Code of Business Conduct and Ethics expressly prohibits paying, offering, accepting, or soliciting bribes in any form, directly or indirectly. Only the Board or the Nominating &and Corporate Governance Committee may waive a provision of the Code of Business Conduct and Ethics with respect to an executive officer or director. Any such waiver will be promptly disclosed on our website and as otherwise required by rule or regulation. There were no such waivers in 2021.

2023.

We also have a Code of Ethics for Senior Financial Officers that includes additional obligations for our senior financial officers (which includes our presidentPresident and chief executive officer, chief operating officer, chief financial officer, chief accounting officer, vice presidentCEO, Co-COOs, CFO, Vice President of finance, treasurer, directorFinance, Treasurer, Director of internal audit, general counsel, operating unit presidentsInternal Audit, General Counsel, Operating Unit Presidents, and operating unit vice presidentsOperating Unit Vice Presidents of finance)Finance).

We encourage employees to disclose alleged wrongdoing that may adversely impact TransDigm, its customers, or stockholders,shareholders, fellow employees or the public, without fear of retaliation. Our Code of Ethics and Whistleblower Policy set forth procedures for reporting alleged financial and non-financial wrongdoing on a confidential and anonymous basis, a process for investigating reported acts of alleged wrongdoing, and a policy of non-retaliation. Reports may be made directly to a supervisor, human resources, operating unit management, executive management, the Chief Financial Officer orCFO, the Chief Compliance Officer, the Audit Committee, or Convercent, a third-party service retained on behalf of the Audit Committee. The Audit Committee chairChair receives notices of complaints and oversees investigation of complaints of financial wrongdoing.

The Board of Directors reviewshas the responsibility to review, approve, and must approveratify all related party transactions. Proposed transactions between TransDigm and related persons are submitted to the full Board for consideration.consideration on a case-by-case basis taking into account all relevant factors, including whether the terms and conditions are at least as favorable to us as if negotiated on an arm’s-length basis with unrelated third parties. The relationship of the parties and the terms of the proposed transaction are reviewed and discussed by the Board, and the Board may approve or disapprove TransDigm entering intoreject the transaction. All non-de-minimis related party transactions, whether or not those transactions must be disclosed under applicable regulations, are approved by the Board pursuant to these policies and procedures.

Although TransDigm’s policies and procedures for related party transactions are not in writing, the policy.

review, approval and ratification of such transactions are documented in the minutes of the Board meetings.

We significantly increased our business across ashareholder engagement in 2023, both in terms of the number of shareholder calls and when we solicit feedback from shareholders. We increased the number of shareholder engagement calls by nearly 250% as compared to 2022. We have established a more robust and formalized shareholder engagement program in which we solicit feedback from our shareholders both before and after our 2023 Annual Meeting.

TransDigm believes that dialogue with shareholders and key stakeholders affords our Board and leadership team valuable insights on the most important topics facing our business. We are committed to building our relationships with our shareholders, and we value their perspectives.

Given the unsatisfactory Say-on-Pay results of approximately 51% approval at our 2023 Annual Meeting, our Board has been particularly focused on engagement so we can better understand and be responsive to our shareholders. The feedback we received this year has led to several important changes, including in our Stakeholder Report which details our commitments, programs, and progress on the environment, diversity, labor and human rights, and ethics. Our Stakeholder Report can be found at www.transdigm.com/investor-relations/corporate-governance.

Stockholder Engagement

We proactivelyhow we plan to continue to engage with stockholders and other stakeholdersshareholders moving forward.

We engage with our shareholders throughout the year on the issues that matter to learnthem and matters that are important to TransDigm. Members of our leadership team meet with investors in a variety of forums, including investor conferences, meetings, calls, and other events. Our executive team and Board regularly review shareholder feedback and evaluate the best ways to be responsive while considering the diverse views of all of our key stakeholders and staying true to our vision and culture.

Prior to 2023, our shareholder engagement on compensation and governance matters generally consisted of outreach during the period of time between the proxy statement filing and our annual meeting date. Our more formal and enhanced engagement program implemented in 2023, not only includes outreach to shareholders leading up to the annual meeting, but a cycle of outreach mid-year (late summer to fall) to gather feedback subsequent to our annual meeting. Our formalized engagement program is also more robust in our efforts to solicit feedback including persistent follow-up to the shareholders contacted to ensure TransDigm is doing our best to engage with a significant portion of our shareholder base and giving shareholders the opportunity to voice their perspectivesfeedback whether it be positive or constructive.

We received valuable feedback in our conversations with shareholders, and many of our conversations focused specifically on significant issues, including company performance and strategy, corporate governance,our executive compensation program. The Compensation Committee, and environmental, social, and governance topics. This engagement helps us better understand stockholder priorities and perspectives, gives us an opportunity to elaborate upon our initiatives and practices, and fosters constructive dialogue. We takethe Board as a whole, has spent a great deal of time evaluating the feedback and insights fromidentifying enhancements to our engagement with stockholderscompensation program and other stakeholders into consideration asoverall governance structure to address the concerns that were voiced. While we reviewrecognize that we have not been responsive to every individual piece of feedback received, we did thoughtfully consider each piece of feedback. We are pleased to say that we have made meaningful improvements that address our shareholders’ key concerns. Below is a summary of the feedback that we received and evolve our practices and disclosures, and further share them with our Board as appropriate.

the improvements we have made in response.

This section describes the experience and qualifications of our Board members and how they are compensated.

Directors

TransDigm’s

At the annual meeting, proxies cannot be voted for a diverse groupgreater number of highly qualified leadersindividuals than the ten director nominees named in their respective fields. Mostthis proxy statement. Holders of ourproxies solicited by this proxy statement will vote the proxies received by them as directed on the proxy card or, if no direction is made, for the election of the Board’s ten nominees.

Each of the directors have senior leadership experience at major domestic and multinational companies. In these positions, they have gained significant and diverse management experience, including strategic and financial planning, mergers and acquisitions, capital allocation, public company financial reporting, compliance, risk management, and leadership development. They also have experiencenominated by the Board has consented to serving as executive officers,a nominee, being named in this proxy statement, and serving on the Board if elected. Each director elected at the annual meeting will be elected to serve a one-year term. If any nominee is unable to serve or on boards of directors and board committees, and have an understanding of corporate governance practices and trends. In addition, many of our directors have experience serving nonprofit and philanthropic institutions, and bring unique perspectives to the Board.

Each Board member was chosen to beotherwise will not serve as a director at the time of the annual meeting, the proxy holders may vote for any nominee becausedesignated by the Nominating & Corporate Governance Committeepresent Board to fill the vacancy.

The Nominating & Corporate Governance Committee and the Board believe that these skills and qualifications, combined with each director’s diverse background and ability to work in a positive and collegial fashion, benefit TransDigm and its stockholders by creating a strong and effective Board.

The Nominating & Corporate Governance Committee recommends potential director candidates to the Board. The Nominating &and Corporate Governance Committee identifies nominees by first determining whether current Board members are willing to continue in service. If any Board member does not wish to continue to serve, or if the Nominating &and Corporate Governance Committee or Board decides not to nominate a member for re-election, then the Nominating &and Corporate Governance Committee initially identifies the desired skills and experience in light of the criteria outlinedduties and responsibilities required of a member of our Board and the Board’s oversight role described above. The Nominating &and Corporate Governance Committee then establishes potential director candidates from recommendations from the Board, senior management, stockholdersshareholders, and third parties. The Nominating &and Corporate Governance Committee may retain a search consultant to supplement potential Board candidates if it deems it advisable. In making its recommendations, consistent with the Nominating &and Corporate Governance Committee’s charter, the Committee considers each candidate’s independence, character, ability to exercise sound judgment and demonstrated leadership, as well as diversity, age,

Our Board is comprised of members with input from our independent directors, Chairmanvaried experiences and backgrounds, which we believe enables thoughtful decision-making. The skills matrix below provides an overview of the levels of experience that each of our Board members has in areas that impact our business: accounting/audit/financial experience, global business experience, mergers and CEO, identified Jane Cronin as a potential candidateacquisitions, risk management, corporate governance, senior leadership experience, operations and recommended her tobusiness strategy, cybersecurity, and human capital management. The Board assesses the skills of its members and whether additional skills or training would enhance the Board. Ms. Cronin was appointed toAs a result of this process, the Board is considering providing opportunities to deepen its experience in June 2021.

cybersecurity.

The Nominating &and Corporate Governance Committee will consider stockholdershareholder suggestions concerning qualified candidates for election as directors. To recommend a prospective nominee forto the Nominating &and Corporate Governance Committee’sCommittee for consideration, a stockholdershareholder must submit the candidate’s name and qualifications to TransDigm’s Secretary Halle Martin, at the following address: TransDigm Group Incorporated, 1301 East Ninth Street, Suite 3000, Cleveland, Ohio 44114. The Nominating &and Corporate Governance Committee has not established specific minimum qualifications a candidate must have in order to be recommended to the Board. However, in determining qualifications for new directors, the Nominating &and Corporate Governance Committee will consider potential members’ independence, as well as diversity, age, skill and experience in the context of the Board’s needs as described above. StockholdersShareholders who wish to nominate directors directly for election at an annual meeting should do so in accordance with the procedures in our bylaws.Bylaws. In addition, the bylawsBylaws provide proxy access to eligible stockholders.shareholders. The proxy access bylaw provides that a stockholder,shareholder, or group of up to 20 stockholders,twenty shareholders, owning at least 3% of our outstanding common stock continuously for at least three years may submit director nominees for the greater of two directors or 20% of the Board seats provided that the stockholdershareholder and nominees satisfy the requirements specified in our bylaws.Bylaws. See “STOCKHOLDER PROPOSALS FOR 2023 MEETING”“Shareholder Proposals for the 2025 Annual Meeting” for more information about the procedures for direct nominations and proxy access.

Among our 11 nominees for election to the Board, two self-identify as women and one self-identifies as an individual from an underrepresented community.