Army Drone Flies on Jet Fuel Rotary Engine
The 3D-printed engine powers a mid-sized aircraft in a research demonstration, with military partner testing still to come.
Updated on Nov. 2, 2026 in Robotics
The U.S. Army Research Laboratory flew a mid-sized drone powered by a 3D-printed rotary engine that runs on jet fuel. The flight date was not disclosed. The work is a research demonstration rather than a fielded system.
Why it matters
Most small and mid-sized drone engines are designed for gasoline, which forces units to carry a separate fuel supply for unmanned aircraft. A rotary engine that burns the same heavy fuel as Army vehicles and helicopters points toward simpler logistics for military drone fleets.
The engine is an air-cooled rotary design that drives a generator in a series-hybrid system, with its 400-volt motor-generator sized for a Group 3 aircraft of up to about 600 kg. The source does not report measured fuel-efficiency or power figures from the flight.
The players
U.S. Army Research Laboratory
The Army's research arm, which led the rotary-engine work and flew the VICTOR drone and PULSAR swarm concept under the Versatile Tactical Power and Propulsion program.
Griffon Aerospace
An Alabama-based aerospace company whose Valiant was a finalist in the Army's Future Tactical Uncrewed Aircraft System competition and which partnered on the VICTOR aircraft.
The details
The lab used computer modeling of fuel flow and designed the rotary engine from scratch to improve how fuel sprays and vaporizes. It then used advanced manufacturing, including 3D metal printing, to rapidly redesign engine components. In the series-hybrid layout, the engine drives a generator that supplies electric power to the aircraft's motor.
Timeline
The flight took place on an undisclosed date.
The Tech Race
Griffon's Valiant was one of two finalists in the Army's Future Tactical Uncrewed Aircraft System competition, placing the VICTOR work in an active contest for tactical drones. The rotary-engine program ran alongside the Versatile Tactical Power and Propulsion effort, which produced hundreds of scientific papers and dozens of patents and patent applications.
The VICTOR drone and PULSAR swarm concept will be made available to military partners for further testing and development, so the rotary engine is not yet in service. No timeline for fielding or public availability was announced.
The takeaway
Watch for results from the military-partner testing of VICTOR and PULSAR, which will show whether a jet-fuel rotary engine holds up outside the lab. Further published papers from the Versatile Tactical Power and Propulsion program would also indicate how the design performs against conventional engines.
Further reading
Explore more Robotics coverage to see how unmanned aircraft are advancing across military and commercial applications.
