Proposal Engineer - Aircraft Modifications Location: Frimley, Surrey, UK A leading global aerospace engineering and services organisation is seeking a Proposal Engineer to join its European modifications team. The team holds EASA Part 21 Design Organisation Approval (DOA) and delivers approved aircraft modifications to customers worldwide. This role focuses on developing proposals for aircraft modification projects, mainly involving cabin electrical systems, inflight entertainment (IFE), connectivity, and avionics systems. You''ll work closely with engineering, programme management, sales, and supply chain teams, with mentoring and training provided to help you get up to speed. Key Responsibilities Review customer requests for proposals (RFPs) and help determine bid/no-bid decisions. Work with customers and internal teams to define modification requirements. Research and develop statements of work and bills of materials. Identify risks and define mitigation strategies. Establish proposal assumptions and limitations based on available information. Liaise with departments to confirm task hours and costs. Collate information into proposal estimates and secure approvals. Track active RFPs and support handover to project delivery teams. Attend customer kick-off meetings when required. Occasional UK or international travel. Skills and Experience Minimum 5 years in the aviation, aerospace, or a related engineering sector. Knowledge of EASA CS25 requirements for aircraft electri