Lead Mechanical Engineer, Airframe

About Poseidon Aerospace:Poseidon Aerospace is reimagining how the world moves goods. We build and operate full-size autonomous cargo aircraft - capable of carrying two tons of payload over a thousand nautical miles. From remote communities to contested logistics operations, our platforms unlock a new cost curve for air freight, making it faster, cheaper, and accessible anywhere it's needed. Headquartered in the San Francisco Bay Area with locations in Washington DC, Oregon, and Maine; we're building something consequential.About the RoleThe Lead Mechanical Engineer will own the structural and mechanical design of major aircraft assemblies from concept through flight testing.This role is responsible for setting technical direction, leading design reviews, managing subsystem interfaces, and supporting other mechanical engineers. It is a hands-on engineering position that requires detailed involvement in CAD, analysis, manufacturing, assembly, and testing.ResponsibilitiesLead the design of primary aircraft structures, mechanisms, and major airframe assembliesDevelop composite and metallic structures, joints, interfaces, and mounting systemsDefine structural load paths, design requirements, margins, and validation methodsPerform and review hand calculations and finite element analysisEvaluate strength, stiffness, buckling, fatigue, vibration, and composite failure modesLead preliminary and critical design reviewsOwn CAD assemblies, production drawings, bills of materials, tolerances, and design releasesManage mechanical interfaces between the airframe, propulsion, avionics, flight controls, landing systems, and other subsystemsDesign aircraft mechanisms, including control surfaces, doors, landing gear, actuation systems, and deployable systemsWork with manufacturing to develop tooling, assembly processes, inspection methods, and repair proceduresPlan and support component, structural, subsystem, and vehicle-level testingInvestigate failures, determine root causes, and implement corrective actionsMentor mechanical engineers and review their design and analysis workSupport aircraft assembly, integration, ground testing, and flight testingRequired QualificationsDegree in Mechanical Engineering, Aerospace Engineering, or a related field7 or more years of relevant mechanical, structural, or aerospace engineering experienceExperience designing primary aircraft structures or large composite airframesExperience with bonded composite structures, sandwich panels, bonded inserts, and hybrid composite-metallic assembliesExperience with aircraft mechanisms, actuation systems, control surfaces, doors, landing gear, or deployable systemsKnowledge of composite failure criteria, buckling, fatigue, vibration, modal analysis, or damage toleranceExperience taking safety-critical hardware from concept through manufacturing and testingStrong proficiency with CAD software such as Fusion, SolidWorks, CATIA, NX, or CreoStrong proficiency with finite element analysis tools such as ANSYS, Nastran, Abaqus, Fusion Simulation, or similarAbility to verify analysis using hand calculations and first-principles methodsStrong understanding of structural mechanics, load paths, joint design, material behavior, and mechanical failure modesExperience applying GD&T and mechanical tolerancing to production drawingsExperience designing for manufacturing, assembly, inspection, maintenance, and repairExperience leading technical reviews and making design decisions across multiple engineering teamsComfortable working directly with aircraft hardware, prototypes, test fixtures, and shop toolsPreferred QualificationsExperience designing structures for marine environmentsExperience developing structural test plans, fixtures, instrumentation, and acceptance criteriaFamiliarity with FAA certification, military airworthiness, or experimental flight-test programsProficiency with MATLAB or Python for engineering analysisExperience with product lifecycle management and configuration control systemsCandidates who are not yet qualified for a Lead position may apply to our Mechanical Engineer openings.What you get from usCompetitive salary and meaningful early-stage equityRelocation support if applicableEmployee Health Benefit Plans6% Retirement matchingFlexible PTOFree lunches, snacks, and a stocked fridge at our officesAI tools and subscriptions