Northrop Grumman’s XRQ-73 uncrewed aircraft has begun flight testing at Edwards Air Force Base, California, under DARPA’s Series Hybrid Electric Propulsion AiRcraft Demonstration programme, known as SHEPARD, the company stated.
The XRQ-73 uses a hybrid-electric propulsion system that combines a conventional fuel source with electric power. According to Northrop Grumman, the configuration offers improved fuel efficiency, reduced emissions, and greater operational flexibility compared to conventionally powered aircraft of similar size. The programme is focused on advancing propulsion technologies for lightweight autonomous aircraft, with DARPA using the demonstration to explore next-generation options for that class of platform.
DARPA has long invested in propulsion research as a means of expanding the operational envelope of uncrewed systems, particularly in the lightweight category where endurance, efficiency, and noise signature can be critical factors. Hybrid-electric architectures have attracted growing interest across both military and commercial aviation in recent years, with proponents arguing they can offer the range benefits of fuel-based systems alongside the mechanical simplicity and lower thermal signature of electric propulsion.
Northrop Grumman states it has accumulated more than 500,000 autonomous flight test hours across seven decades of work in autonomy, a lineage that spans platforms from early reconnaissance drones through to the B-21 Raider’s supporting autonomous systems work. The company designed and built the XRQ-73 for the SHEPARD programme.
Edwards Air Force Base, located in the Mojave Desert, is the U.S. military’s primary flight test centre and has been the site of some of the most significant aircraft development programmes in aviation history. Its restricted airspace and extensive test infrastructure make it the standard choice for early-stage flight demonstrations of experimental platforms.
