Principal Mechanical Engineer

Principal Mechanical Engineer Salary: Up to £75,000 per annum Location: Near Addlestone, Surrey Hours: 37.5 hours per week Type: Permanent Are you a recognised Mechanical Engineering expert looking for a role where your technical decisions genuinely shape projects, products, and business performance? We’re supporting a highly innovative engineering business in the defence sector in their search for a Principal Mechanical Engineer (Mechanical SME) to act as the organisation’s go-to Subject Matter Expert across all mechanical engineering matters. This is a high-impact position focused on technical excellence, governance, problem-solving, and innovation rather than people management—ideal for someone who wants to remain hands-on technically while influencing engineering strategy across multiple programmes. What’s in it for you? * Salary up to £75,000 depending on experience, Paid overtime or time off in lieu * Flexible working hours with core hours in place, Competitive employer pension contribution, Private medical care, Holiday closedown over Christmas * Ongoing training and development, Salary sacrifice schemes, Company laptop / mobile / home office equipment * Relocation package available for the right candidate Security / Eligibility Requirements – Please Read Before Applying Due to the nature of the work and security clearance requirements, applicants must meet the following criteria: * Must hold a British passport * No dual nationality due to security clearance restrictions * Ideally British-born, although applications may be considered on a case-by-case basis * Must be eligible to obtain high-level UK Security Clearance / DV clearance Principal Mechanical Engineer Role As the Mechanical Engineering Subject Matter Expert, you will: * Act as the recognised SME for all mechanical engineering matters across the organisation * Provide high-level technical guidance across multiple projects and programmes * Lead complex problem-solving and root cause analysis for critical engineering issues * Review and approve mechanical designs, calculations, and technical documentation * Ensure solutions are robust, manufacturable, and aligned with operational requirements * Support design reviews, risk assessments, and engineering assurance activities * Act as the escalation point for high-risk or technically complex decisions * Complete mechanical design activities from concept through to manufacture * Support bids, proposals, and project planning with expert technical input * Work closely with electronics, production, and test teams to deliver integrated engineering solutions * Identify technical risks and opportunities early and recommend mitigation strategies * Mentor and coach engineers, apprentices, and junior team members * Drive innovation in mechanical design, engineering methods, and product improvement What We’re Looking For * Extensive experience in Mechanical Engineering within defence, engineering, or manufacturing environments * Proven track record of solving complex engineering challenges * Experience across the full product lifecycle from concept to manufacture * Deep understanding of mechanical design, analysis, and materials * Strong understanding of engineering standards, compliance, and safety requirements * Ability to influence and guide teams without direct line management authority * Excellent analytical and problem-solving skills * Degree in Mechanical Engineering or related discipline (or equivalent experience) * Chartered Engineer status, or working towards, would be advantageous This is an excellent opportunity for a senior-level engineer to join a growing and innovative business where your expertise will have a direct impact across multiple departments and high-profile engineering programmes. To Apply, press the apply button and one of the team will be in touch. INDA