Senior Mechanical Engineer

L3Harris is dedicated to recruiting and developing high-performing talent who are passionate about what they do. Our employees are unified in a shared dedication to our customers’ mission and quest for professional growth. L3Harris provides an inclusive, engaging environment designed to empower employees and promote work-life success. Fundamental to our culture is an unwavering focus on values, dedication to our communities, and commitment to excellence in everything we do.

L3Harris is the Trusted Disruptor in defense tech. With customers’ mission-critical needs always in mind, our employees deliver end-to-end technology solutions connecting the space, air, land, sea and cyber domains in the interest of national security.

Our Brighton business is moving to a new location in 2027. The new site is expected to be located in either Shoreham, Burgess Hill or Horsham and will be within a 15-minute drive of our current site.

Operating at 11 sites in the United Kingdom, L3Harris supports Britain's mission to secure and strengthen the country by delivering sovereign innovation across the space, air, land, sea and cyber domains.

L3Harri s in Brighton are part of our Release Systems & Antennas division operating in the Aerospace domain. For over 70 years, L3Harris has designed and developed industry-leading carriage and release systems for fighter, rotary-wing and unmanned platforms and we design, manufacture and test a large portion of our release systems portfolio in our Brighton facility which offers 48,500 square feet of manufacturing space. Our mission-critical release systems equipment is on most major airborne fighter platforms worldwide, including the F-35, along with other aircraft like the Gripen and Typhoon.

The Senior Mechanical Engineer (MEP4) is a senior technical professional responsible for providing technical design input, engineering judgement and design assurance across complex mechanical and electro‑mechanical products and programmes. The role contributes directly to design definition and decision‑making while maintaining a primary focus on technical governance, integration and lifecycle suitability, rather than routine detailed design execution.

The role operates with general oversight, influences technical outcomes across multiple functions, and ensures engineering solutions are compliant, robust, manufacturable and aligned with programme and customer requirements. The role may lead assigned work packages or, where appropriate, an engineering programme, without line management responsibility.

• 
  
• Half day finish on a Friday
  
• 25 days holiday per year (plus bank holidays), increasing with long service and with the opportunity to buy/sell up to 5 days
  
• Private medical insurance with optional family cover
  
• Pension scheme of up to 8% employer contribution
  
• Life Assurance 4x salary (flexible up to 10x)
  
• Group income protection
  
• Flexible opt‑in extras such as a health care cash plan, dental insurance, gym membership, cover critical illness, cycle to work scheme, travel insurance and electric car scheme
  
• Employee Family Assistance Program providing mental health and wellbeing support
  
• Professional membership reimbursement (discretionary)
  

The responsibilities of your role will include the following:

• 
  
• Provide technical design input to mechanical architectures, interfaces and key design features.
  
• Lead assigned work packages and, where appropriate, an engineering programme (Project Engineering Lead), with accountability for technical scope, delivery, risk and engineering outcomes Contribute to design trade studies, concept evaluation and selection of technically robust solutions.
  
• Coordinate engineering activities across disciplines in support of work package or programme objectives, without line management responsibility.
  
• Guide design intent and ensure alignment with requirements, environmental constraints and lifecycle considerations.
  
• Review, approve and technically assure mechanical design outputs including drawings, analyses, specifications and substantiation evidence.
  
• Assess design feasibility against cost, schedule, manufacturability, maintainability and lifecycle constraints.
  
• Address complex technical issues escalated from project teams, manufacturing or suppliers.
  
• Interface with customers and suppliers to clarify technical requirements and communicate agreed engineering approaches.
  
• Provide technical input to cost and schedule estimates in support of programme activities.
  
• Ensure compliance with applicable standards including BS8888, ISO 1101 and internal engineering governance requirements.
  

The role requires the following experience and skills:

The ideal candidate should be a highly skilled and experienced mechanical engineering professional with a strong technical foundation and proven ability to deliver complex technical output across aerospace or defence programmes.

The person should be analytical, methodical and systems orientated capable of guiding design solutions and resolving complex engineering issues ensuring compliance with programme requirements considering technical and regulatory standards.

• 
  
• Strong successful experience in delivery of engineering programmes/tasks in defence and aerospace domains.
  
• Experience in requirements engineering including interpreting and managing mechanical requirements and specifications throughout lifecycle.
  
• Understanding and implications of risk management associated to tasks within allocated programmes/deliverables.
  
• Ability to work independently, manage competing priorities with project management and be accountable for technical decision whilst under governance oversight.
  
• Complex mechanical engineering calculations and a good understanding of FEA; Geometric Tolerancing, Stack‑Up Analysis
  
• Technical Report writing.
  
• BEng, BSc in Mechanical / Aerospace Engineering with minimum 6 years of relevant experience, or MEng, MSc with 4 years minimum experience or lieu of degree HNC or HND with 10 years experience.
  

• 
  
• Prior hands‑on experience with 3D CAD tools and PDM, ensuring configuration control.
  
• Familiarity with MRP and manufacturing engineering.
  
• Experience in supporting technical reviews, work planning and schedules.
  

Due to the nature of our work many our roles require a UK nationality and the ability to obtain a security clearance. Applicant who accept a conditional offer of employment must meet the requirement of right to work in the UK and must meet eligibility requirements for access to classified information and will be subject to government security checks.

#SeniorMechanicalEngineer

#LI-RT1

L3Harris Technologies is proud to be an Equal Opportunity Employer. We are committed to maintaining a workplace that is free from unlawful discrimination and offers equal opportunities for all. Applications from individuals are encouraged regardless of age, disability, sex, gender reassignment, sexual orientation, pregnancy and maternity, race, religion or belief, and marriage and civil partnerships.