Senior Mechanical Stress Engineer - Part 21J, Aircraft Modifications£60,000 - £80,000 base + benefitsDublin OR Frimley (Farnborough Area) - HybridAbout the OpportunityWe are hiring for a Senior Mechanical Stress Engineer to lead the structural substantiation and certification of large commercial aircraft modifications within an EASA Part 21J Design Organisation environment.This is a senior-level technical role offering the opportunity to act as a stress and certification focal point, lead complex engineering activities, and mentor other engineers across multiple high-profile modification programmes.Key Responsibilities- Lead structural analysis and certification activities for commercial aircraft modification programmes- Act as the technical authority and focal point for stress and structures-related queries- Perform and review hand calculations, classic stress analysis and FEA- Prepare and approve structural substantiation reports and certification documentation- Ensure compliance with EASA/FAA airworthiness regulations and DOA processes- Support design reviews, risk assessments and technical decision-making- Mentor and coach junior and mid-level engineers- Represent engineering at customer and programme milestone meetings (PDR, CDR, FAI, etc.)- Collaborate with global, cross-functional engineering teams across multiple time zonesTypical Project ScopeYou may support certification and integration of:- Seating installations- Galleys, lavatories, monuments and VVIP interiors- Cabin layout and LOPA changes- LRU installations and PSU reconfigurations- Antenna and equipment installations- Fuselage and primary structure modificationsSkills & Experience Required- Degree in Aerospace, Aeronautical or Mechanical Engineering- Current or recent experience within an EASA Part 21J Design Organisation (or equivalent)- Strong background in aircraft stress analysis and structural substantiation- Proficient with hand calculations, classical methods and FEA tools- Experience compiling technical reports and certification artefacts- Working knowledge of EASA airworthiness regulations (CS-25 / FAR 25 / ETSO)- Experience supporting certification of aircraft interior and/or primary structure modifications- Ability to manage multiple projects and prioritise effectively- Excellent communication and stakeholder engagement skillsHighly desirable:- Previous experience acting as a Compliance Verification Engineer (CVE)- Experience leading technical reviews or acting as a subject matter expert- Mentoring or team leadership experienceAbout You- A confident technical specialist and problem solver- Comfortable leading complex engineering decisions- Detail-oriented with strong professional integrity- Able to influence stakeholders and customers- Passionate about mentoring and raising engineering standardsWhat's on Offer- Work on large-scale, real-world commercial aircraft modifications- Senior technical ownership and influence- Exposure to global airline customers- Structured career progression within a Part 21 environment- Collaborative engineering culture- Competitive salary and benefits