Principal Thermal Engineer - Aircraft Avionics & Thermal Systems

About the role

Shield AI, a defense-tech company developing aircraft and autonomy software, is hiring a Principal Thermal Engineer in Seattle. You will own the technical direction, architecture and development of aircraft avionics thermal management systems, covering aircraft-level thermal and fluid systems, and lead complex, cross-functional engineering efforts.

Key responsibilities

• Own thermal architecture, analysis and design strategy for UAV avionics and aircraft-level thermal and fluid systems across programs.
• Lead cross-functional trade studies and technical decisions, balancing thermal performance with power, weight, volume, reliability, manufacturability and aircraft integration.
• Develop and validate heat transfer and fluid flow models by hand calculation and CFD tools such as FloEFD, and set modeling standards.
• Define verification and validation strategies, guiding test planning, instrumentation and data analysis.
• Serve as technical authority in executive briefings, design reviews and customer discussions.
• Identify and retire system-level risks, influence electrical and PCBA design, and resolve interfaces across avionics, mechanical and aircraft systems.
• Establish reusable thermal design methods, mentor engineers and build thermal engineering capability.

Required profile

• B.S. in Mechanical Engineering, Aerospace Engineering or a related discipline.
• At least 12 years of professional experience in avionics or electronics thermal engineering, including technical leadership of complex, multidisciplinary systems.
• Proven track record of owning thermal architecture and delivering solutions from concept through integration, verification and validation.
• Ability to obtain a S//SAR level security clearance desired.

Required skills

• Heat transfer and fluid mechanics applied to system architecture.
• Active and passive cooling, TIMs, spreaders, heat sinks, vapor chambers, heat pipes and fans.
• CFD tools such as ANSYS Icepak, FloEFD, STAR-CCM+; CAD tools such as NX or SolidWorks.
• First-principles reasoning, mentoring engineers and presenting to executive stakeholders.

Preferred: M.S. or Ph.D.; experience with high-altitude aircraft avionics cooling and trade studies; knowledge of pumps, heat exchangers and composites.