Staff Mechanical Engineer – Propulsion

Firestorm•San Diego, CA

1d•Onsite

About The Position

At Firestorm, we are building the future of expeditionary defense manufacturing and autonomous systems. Modern conflict has exposed a fundamental problem: the systems needed most by operators are often too expensive, too slow to produce, and too difficult to sustain at scale. Firestorm exists to change that. We develop mission-adaptable aerial systems and deployable manufacturing infrastructure designed to put capability directly into the hands of the warfighter. From modular unmanned aircraft to xCell — our deployable microfactory — our goal is to make defense systems rapidly deployable, adaptable, and producible at the point of need. We are looking for builders, operators, and problem-solvers who want to work on meaningful technology with real-world impact. As a Staff Propulsion Engineer at Firestorm, you will own the propulsion systems that power our sUAS platforms—from small piston and heavy-fuel engines to the fuel, induction, ignition, and exhaust architectures that surround them. You will be responsible for engine selection, integration, calibration, and qualification across Firestorm’s fuel-based aircraft, translating mission endurance and performance requirements into producible powerplant solutions. This is a deeply hands-on, full-time role. You will spend time at the test stand, in the engine cell, and on the flight line. You will design and instrument test articles, develop ECU calibrations, investigate failures, and partner with airframe and systems engineering to make sure our propulsion systems deliver power, endurance, and reliability across the full operational envelope.

Requirements

Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or a related field (Master's degree preferred)
7+ years of experience in propulsion engineering, preferably with small piston engines, heavy-fuel engines, or small gas turbines
Deep working knowledge of internal combustion fundamentals: thermodynamic cycles, AFR, combustion, knock, ignition systems, and exhaust
Hands-on experience designing and operating engine test stands, including dyno instrumentation, fuel flow measurement, EGT/CHT instrumentation, and data acquisition
Experience with EFI systems and ECU calibration (EFI Technology, MoTeC, Currawong, or equivalent)
Experience with fuel system design across the full flight envelope—including altitude, attitude, and thermal effects on fuel delivery and pressure
Demonstrated history of running structured failure investigations and translating findings into multi-phase test campaigns
Proficiency in Python or MATLAB for engine data reduction, log analysis, and performance modeling
Familiarity with propeller selection and matching for fixed-wing platforms
Excellent problem-solving skills and attention to detail
Strong communication and teamwork skills
Ability to work in a fast-paced and dynamic startup environment
U.S. Citizenship and ability to obtain and maintain a U.S. Government security clearance

Nice To Haves

Experience with sUAS or Group 1–3 unmanned aircraft propulsion
Experience with heavy-fuel (JP-5/JP-8) engine integration and qualification
Experience reverse-engineering proprietary ECU data formats or building custom log analysis pipelines
Background in flight test, including FAA Part 107 or Part 61 operations

Responsibilities

Own development and integration of both small piston engines and micro turbojet propulsion systems, including engine selection, inlet/exhaust configuration, fuel and ignition architecture, thrust and power characterization, and ground/flight test campaigns tailored to each propulsion type.
Develop and execute engine test plans on test stands and in-flight: power and torque mapping, BSFC characterization, endurance runs, vibration surveys, and altitude/temperature performance testing.
Lead engine calibration and tuning, including AFR targets, EGT management, ignition timing, and injector strategy on EFI-equipped powerplants; identify and mitigate single-injector maldistribution and other cylinder-to-cylinder variability.
Design and analyze fuel systems—tanks, lines, pumps, filters, regulators, and fuel pressure management—across the full flight envelope, including negative-G and altitude effects.
Investigate and root-cause propulsion anomalies (RPM collapse, lean events, misfires, mechanical failures); develop structured multi-phase test plans and drive corrective action.
Specify and qualify propellers in coordination with aerodynamics, balancing thrust, efficiency, ground clearance, acoustic signature, and vibration.
Develop and maintain propulsion engineering documentation: interface control documents, test plans and reports, propulsion budgets (power, fuel burn, endurance), and configuration baselines.
Partner with thermal engineering on engine cooling, exhaust routing, and heat rejection.
Partner with electrical engineering on ECU integration, sensor selection, harnessing, and telemetry.
Interface with engine OEMs, fuel system vendors, and propeller manufacturers as the technical lead for propulsion procurement and qualification.
Travel to test sites and customer locations to support propulsion test events and field troubleshooting.

Benefits

Comprehensive medical, dental, and vision plans
401(k) Retirement Savings Plan
Equity grants for new hires
Unlimited PTO
Extremely generous company holiday calendar, including a holiday hiatus in November & December
Generous Parental Leave
Lifestyle Spending Account
FSA
DCFSA
HSA
Hospital Indemnity insurance
Critical Illness insurance
Accident insurance
Basic Life/AD&D, short-term and long-term disability insurance, 100% covered by Firestorm.
Option to purchase additional life insurance for you and your family.
Mental Health Resources: free mental health resources 24/7 including therapy and more.
Additional work-life services, such as free legal and financial support.