Mechanical Senior Principal Engineer in London

UK CITIZENSHIP REQUIRED FOR THIS POSITION: Yes

RELOCATION ASSISTANCE: Relocation assistance may be available

TRAVEL: Yes, 10% of the Time

Location: New Malden

Salary: £75,000 - £90,000

Clearance: SC (or eligible)

What’s Your Possible? At Northrop Grumman UK, you are part of a team driving innovation where it matters most – solving tomorrow’s challenges and shaping the technology and solutions of the future. It’s what we call Defining Possible. This mindset goes beyond the solutions we deliver; it shapes your career development and the impact you can make within the community.

The Opportunity This is more than just a job; it’s a mission. As a Senior Principal Mechanical Engineer, you will hold a key senior position within the Defence Operating Unit’s engineering function. You will act as a technical expert and leader, guiding hardware engineers in the development of electro‑mechanical products that are production‑ready, robust and compliant with industry standards. You will lead some of the most complex and critical projects, applying deep expertise in mechanical design, materials, manufacturing processes and regulatory standards. You will influence technical strategy, develop people, improve processes and drive continuous improvement across engineering programmes.

Role Responsibilities

• Lead the design, development and delivery of mechanical products, ensuring they are optimised for manufacture and aligned to safety, security, maintainability and quality requirements.
• Provide technical leadership as the subject matter expert across mechanical engineering, materials and manufacturing processes.
• Independently deliver hardware artefacts, review complex technical documentation and drive solutions to highly technical challenges.
• Lead planning activities, estimate effort, monitor progress and ensure successful delivery against cost, time and quality targets.
• Review and assure the quality of mechanical deliverables across prototyping, testing and validation phases.
• Liaise with customers and suppliers, communicating complex issues and building trusted relationships.
• Mentor, coach and develop engineers across the operating unit to strengthen capability.
• Drive root‑cause analysis, risk mitigation, corrective actions and continuous improvement initiatives.
• Apply up‑to‑date knowledge of standards, regulations, materials and manufacturing methods across aerospace and defence environments.
• Promote engineering excellence internally and externally through presentations, technical talks and engagement with industry.

Candidate Requirements

Essential

• Degree in Mechanical Engineering or related discipline, or extensive relevant experience.
• Significant experience in the defence, maritime or aerospace sector.
• Strong knowledge of defence mechanical design standards and regulations.
• Experience leading and developing high‑performing engineering teams.
• Ability to lead design from concept through manufacture and into in‑service support.
• Expertise in structural, thermal or dynamic analysis, including experience with finite element analysis.
• Proficiency in engineering drawings, 3D modelling and product documentation.
• Experience with DFMEA, DFA, DFM and continuous improvement methodologies.
• Experience specifying metallic materials and manufacturing processes, including REACH‑ and RoHS‑compliant materials.
• Experience with prototyping, design qualification, production techniques and supply chain engagement.
• Strong communication, influencing and stakeholder‑management skills.

Preferred

• Chartered Engineer status.
• Experience using CREO or similar CAD tools.
• Experience using Windchill or similar PLM systems.
• Experience using AutoCAD Electrical or similar design tools.

If you meet many, but not all of the criteria, we still encourage you to apply. We value potential, curiosity and a commitment to learning.

Security Clearance Due to the nature of our work, you must be eligible for the required UK Government security clearance. You must be able to gain and maintain this clearance throughout your employment.

Benefits

• Flexible and hybrid working options, including compressed working patterns.
• Private healthcare.
• Cash health plan.
• Holiday buy and sell options.
• Career development, mentoring and professional training.
• Performance‑related bonuses.

Why Join Us?

A Mission to Believe In Every day, we help deliver technology that supports national security and contributes to a safer, more connected world.

A Place to Belong and Thrive We are committed to creating an inclusive environment where every voice is valued, and people from all backgrounds can thrive.

Your Career, Your Way Grow your career through diverse roles, hands‑on development, mentoring and opportunities to shape innovative engineering solutions.

Job Category Engineering Northrop Grumman is committed to hiring and retaining a diverse workforce, and encourages individuals from all backgrounds and all abilities to apply and consider becoming a part of our diverse and inclusive workforce.