Principal Mechanical Engineer (Onsite)

Principal Mechanical Engineer El Segundo, CA (US) Eligibility U.S. citizenship required to obtain and maintain a DoD Secret security clearance. Responsibilities Lead the mechanical development of GPS RF and digital electronics subsystems from concept through production. Serve as the mechanical technical authority (REA) on assigned programs, ensuring alignment to technical, cost, and schedule objectives. Own subsystem‑level mechanical solutions, ensuring performance in demanding thermal and high‑vibration environments. Collaborate cross‑functionally with Electrical, Systems, Manufacturing, and Supply Chain teams to deliver integrated hardware solutions. Represent the mechanical discipline in internal and external design reviews and customer engagements. Mentor and provide technical guidance to junior engineers across the matrixed team. Support hardware integration, verification, and production readiness activities within secure program environments. Qualifications Typically requires a STEM degree and a minimum of 8 years of prior relevant experience, or an advanced degree and a minimum of 5 years’ experience. Ability to obtain and maintain a U.S. government‑issued security clearance (U.S. citizenship required). Experience designing and developing electronics packaging solutions for high‑reliability GPS receivers or related military applications. Experience applying Geometric Dimension Tolerance (GD&T) and ASME drawing standards to production hardware. Experience with 3D solid modeling tools (Creo/Pro/Engineer or similar) for mechanical design and documentation. Experience supporting hardware through environmental qualifications (vibration, shock, thermal). Preferred Qualifications Experience with airborne or space electronics, CCA or unit. Experience serving as a subsystem lead, REA, or similar technical authority role. Experience with thermal and structural analysis methods for electronics hardware. Experience with CCA/PCB integration, cabling and harness design, or RF isolation features. Experience supporting design reviews (PDR, CDR, TRR) and presenting technical data to customers. Experience performing root‑cause investigations and implementing corrective actions in production environments. Benefits Medical, dental, and vision insurance. Three weeks of vacation for newly hired employees. Generous 401(k) plan with employer matching funds and a separate employer retirement contribution, including a Lifetime Income Strategy option. Tuition reimbursement program. Student Loan Repayment Program. Life insurance and disability coverage. Optional coverages: pet insurance, home and auto insurance, additional life and accident insurance, critical illness insurance, group legal, ID theft protection. Birth, adoption, and parental leave benefits. Ovia Health, fertility and family planning. Adoption Assistance. Autism Benefit. Employee Assistance Plan (up to 10 free counseling sessions). Healthy You Incentives, wellness rewards program. Doctor on Demand, virtual doctor visits. Bright Horizons, child and elder care services. Teladoc Medical Experts, second opinion program. And more! Equal Opportunity Employment RTX is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability or veteran status, or any other applicable state or federal protected class. RTX provides affirmative action in employment for qualified individuals with a disability and protected veterans in compliance with Section503 of the Rehabilitation Act and the Vietnam Era Veterans’ Readjustment Assistance Act. #J-18808-Ljbffr Prattwhitney