DARPA and Northrop Grumman have started flight testing the XRQ-73, an experimental hybrid-electric unmanned aircraft developed under the Series Hybrid Electric Propulsion AiRcraft Demonstration (SHEPARD) program. The first flight occurred in April 2026 at Edwards Air Force Base in California, in collaboration with the Air Force Research Laboratory.
The XRQ-73, built by Northrop Grumman with involvement from its subsidiary Scaled Composites, weighs approximately 1,250 pounds and falls into the U.S. Department of Defense’s Group 3 unmanned aircraft system category. This classification supports altitudes up to 18,000 feet and speeds up to 250 knots. The aircraft features a flying-wing design with two vertical stabilizers and a hybrid-electric propulsion system that uses a gas turbine to generate electricity for ultra-quiet operation.
The SHEPARD program evaluates this propulsion architecture for improved fuel efficiency, reduced emissions, and lower acoustic and infrared signatures. The XRQ-73 evolved from the earlier XRQ-72A under the Great Horned Owl project. Testing will expand the flight envelope to assess performance under varied conditions. The XRQ designation indicates an experimental role in intelligence, surveillance, and reconnaissance, though other missions remain possible. Scaled Composites test pilot Dr. Mike McLean remotely piloted the initial flight.