# US military heavy-fuel drone technology development > Developing situation record from CLSTR: https://clstr.news/situations/us-military-heavy-fuel-drone-technology-development > Updated: 2026-11-05T02:43:45.000Z. Sources: 5. Developments: 2. The U.S. Army and Navy are advancing unmanned aerial capabilities through research into heavy-fuel propulsion systems. The DEVCOM Army Research Laboratory successfully demonstrated a flight test of a 3D-printed heavy-fuel rotary-engine series-hybrid system integrated into the VICTOR, a mid-sized vertical takeoff and landing unmanned aircraft. This system uses 3D metal printing and computational fluid dynamics to burn heavy fuels like JP-8 or kerosene, which reduces the logistical need for separate gasoline supplies. The hybrid architecture utilizes a motor-generator system to allow the engine to operate at peak efficiency while an electric motor handles propulsion. This technology is intended to enable drones to carry heavier payloads and fly longer distances in extreme environments. In a related effort, the U.S. Navy has scheduled a technology demonstration for the Marine Corps’ Tactical Resupply Unmanned Aircraft System (TRUAS) Increment II in early 2027. This event will invite contractors to showcase cargo drones capable of using diesel or jet fuel rather than batteries to meet requirements for transporting 100-pound payloads over approximately 40 nautical miles. ## Timeline ### 2026-11-05: U.S. Army successfully tests 3D-printed heavy-fuel hybrid drone engine The U.S. Army successfully flight-tested a 3D-printed heavy-fuel hybrid engine for VTOL drones, aiming to increase range and payload capacity while reducing logistical needs. 2 sources. https://clstr.news/cluster/us-army-successfully-tests-3d-printed-heavy-fuel-hybrid-drone-engine ### 2026-11-02: US Navy and Army advance heavy-fuel drone technology The U.S. Army and Navy are developing heavy-fuel drones to improve logistics, featuring 3D-printed engines and upcoming Marine Corps cargo drone demonstrations in Alabama. 3 sources. https://clstr.news/cluster/us-navy-and-army-advance-heavy-fuel-drone-technology --- Cite as: US military heavy-fuel drone technology development. CLSTR, https://clstr.news/situations/us-military-heavy-fuel-drone-technology-development