Principal Mechanical Design Engineer; Technical Lead

Martin-Baker is the world’s leading manufacturer of ejection and crashworthy seats, saving over 7,805 lives to date. We combine cutting-edge engineering with a clear mission: protecting aircrew around the world.

We are now recruiting a Principal Mechanical Design Engineer to join our Mechanical Engineering team at our Denham site.

The Role:

As a Principal Mechanical Design Engineer, you will be responsible for delivering robust, compliant, and commercially viable mechanical designs across the full product lifecycle — from concept through development, qualification, production, and in-service support. You will work closely within Integrated Project Teams to ensure engineering outputs meet regulatory, customer, and internal requirements, while optimising manufacturability, safety, and performance.

You will also support design reviews, drive continual improvement across products and processes, and have responsibility for signing off engineering drawings to ensure correctness, functionality, and compliance with best practice.

Key Responsibilities:

• Develop top-level layouts, 3D models, and detailed engineering drawings.
• Sign off engineering drawings and documents for correctness, functionality, and compliance with best practice.
• Translate customer, regulatory, and internal requirements into robust engineering specifications.
• Participate in trade studies to identify optimal, commercially viable design solutions.
• Perform performance and structural calculations using hand methods, spreadsheets, and FEA tools.
• Generate and maintain engineering documentation including BOMs, DFMEAs, load/stress reports, tolerance analyses, and CE technical files.
• Support trial installations, customer visits, and design reviews.
• Conduct clearance, interchangeability, retrofit, and modification analyses.
• Identify and drive continual improvement opportunities across products, processes, and engineering practices.
• Proactively identify and mitigate risks to safety, performance, quality, and delivery.
• You will also mentor and motivate junior engineers, sharing knowledge and best practice to help the team deliver high-quality engineering outcomes.

About You:

We are looking for an experienced, proactive, and technically strong Mechanical Engineer with a passion for safety-critical aerospace products.

• Degree (1st or 2:1) in Mechanical or Aerospace Engineering (or equivalent experience).
• Chartered Engineer or working towards CEng.
• Extensive experience in mechanical design within aerospace, defence, or regulated engineering environments.
• Expertise in 3D CAD tools (e.g., NX) and producing high-quality engineering drawings.
• Strong understanding of materials, manufacturing processes, and design for manufacture and assembly.
• Experience conducting structural and performance calculations, including FEA.
• Knowledge of GD&T to UK/US standards.
• Ability to produce and deliver technical reports and presentations.
• Strong problem-solving skills and sound engineering judgment.
• Excellent communication and stakeholder engagement skills.
• Experience with motion simulation tools (e.g., NX Motion, ADAMS).
• Knowledge of aerospace/defence standards (MIL-STD, Def Stan).
• Experience in CE certification.
• Hands-on manufacturing or assembly experience.
• Track record of innovative designs or patents.
• 9% non-contributory pension (18+)
• Midday finish on Fridays
• 4x salary Life Assurance (18+)
• Personalised training & development plan
• 25 days holiday + bank holidays
• Option to purchase additional annual leave
• Cycle to Work & nursery benefits
• Discounts via the Martin-Baker+ platform

Your Interview Journey:

• Initial Telephone Interview: A discussion with your Recruitment Business Partner
• First Stage Interview (Microsoft Teams):
  Structured technical interview with the Hiring Manager
• Final Stage Interview:
  Face-to-face interview

Why Join Us?

At Martin-Baker, your work directly contributes to saving lives. You’ll be part of a collaborative, high-performance engineering environment working on safety-critical aerospace systems with real opportunities to make an impact.

This role is subject to UK Government security clearance. Applicants must have the existing right to work in the UK and be currently residing in the UK.