A clandestine, experimental Pentagon drone made its first flight in April after years of preparation, Northrop Grumman and the Defense Advanced Research Projects Agency (DARPA) said Wednesday.
DARPA said that it flew the XRQ-73—a hybrid-electric uncrewed aerial vehicle (UAV) designed to improve fuel efficiency, reduce emissions, and enable stealthier operations—in April at Edwards Air Force Base (KEDW) in California. The XRQ-73 was first and last seen in 2024, when DARPA gave it a designation and Northrop’s Scaled Composites unit unveiled the design.
The XRQ-73 is linked to Northrop’s earlier XRQ-72A project. Both aircraft feature a tailless, flying wing configuration akin to the manufacturer’s B-2 bomber. The XRQ-72A was smaller, lighter, and designed to be extremely quiet. But despite years spent working on the project, DARPA never publicized a test flight.
The XRQ-73 is being developed for DARPA’s Series Hybrid Electric Propulsion AiRcraft Demonstration (SHEPARD) program, which seeks to unlock improved performance for military craft through alternative propulsion systems. Lieutenant Colonel Clark McGehee, manager of SHEPARD, told defense news website The War Zone that the aircraft is undergoing a “short flight test campaign.”
“This effort involved resolving complex, unforeseen technical challenges during ground testing and integration,” McGehee said of delays in testing the aircraft, which was originally intended to fly in 2024.
McGehee in DARPA’s press release added that the “architecture proven by the XRQ-73 paves the way for new types of mission systems and delivered effects.”
In other words, while the drone itself may never enter service, the technologies it is evaluating could be adopted by future military aircraft.
Hybrid-Electric Military Drones
The XRQ-73 is designed and built by Northrop and Scaled Composites. The X in XRQ designates experimental, the R stands for reconnaissance, and the Q denotes that it is uncrewed.
It is classified by the military as a Group 3 uncrewed aircraft system (UAS), meaning it has a maximum weight of 1,320 pounds, top speed of 250 knots, and service ceiling of 18,000 feet. The aircraft has internal engines, contrasting with the XRQ-72A’s externally mounted fan engines.
But other details about the secretive project are scant.
Photos of the April test flight shared by DARPA show what appear to be vertical stabilizers on the aircraft’s wingtips. These were not present in 2024 images. Per The War Zone, the new photos also depict an auxiliary intake, blade antennas, and camera system that were not present on the original design.
A handful of companies, including Joby Aviation, Archer Aviation, Beta Technologies, and Electra, are also developing electric or hybrid-electric vertical takeoff and landing (VTOL) concepts for defense applications. Joby, Archer, Beta, and Electra have partnerships with L3Harris, Anduril, GE Aerospace, and Lockheed Martin for their respective projects.
The Pentagon in recent years has awarded contracts for testing of fully electric versions of these models, which are intended as commercial air taxis. It has purchased aircraft from Archer and Joby outright and conducted testing with Beta’s Alia.
