General Atomics Aeronautical Systems Inc. (GA-ASI) has finalized the qualification trials of its new 200-horsepower heavy fuel engine (HFE 2.0) for the Gray Eagle 25M unmanned aerial system in El Mirage, California.
HFE 2.0 provides a 40 percent increase in the drone’s service life, 50 percent more power to mission payloads, and longer maintenance-free, low-sustainment capability — all required to meet the user requirements in multi-domain operations.
During the three-week event, the technology was evaluated according to the US Federal Aviation Administration’s (FAA) primary performance standard for engines deployed for commercial applications.
The HFE 2.0 was already tested in the last 18 months prior to the FAA assessment, during which it simulated high-stress flights for 200, 400, and 651 hours.
Additionally, the engine completed 50 hours of trials in its flight envelope or overall operational boundaries.
Following these tests, the HFE 2.0-equipped Gray Eagle will be sent for a separate qualification process under the US Army to authorize its usage across the service’s existing Gray Eagle Extended Range drones and replace the fleet’s aging 180-horsepower engine.
“This test is the culmination of the extensive durability and flight test program for the HFE 2.0 engine,” GA-ASI President David Alexander commented on the latest milestone.
“It’s been great to see the outstanding test results that have validated the design and development of the HFE 2.0 engine we have worked on so passionately for the past seven years and to bring this world-class engine to the Gray Eagle fleet.”
Recent Developments
GA-ASI’s Gray Eagle currently serves as an option to fly as the US Army’s next Future Attack Reconnaissance Aircraft (FARA).
The program, now on hold, seeks a modern drone-helicopter team with enhanced radar, imaging solutions, and communication relays to amplify the force’s vertical lift capabilities.
In January 2024, GA-ASI completed the Gray Eagle 25M’s maiden flight in California. This followed a $389-million contract in December 2023 to deliver the drone to the army.
In October 2023, the company began manufacturing the Gray Eagle’s latest configuration with a sensing capability that can detect threats at 50 miles (80 kilometers) away.
Exactly one year earlier, GA-ASI tested the drone’s next-generation flight computer with “increased memory, processing, and a high-speed ethernet interface.”
General Atomics’ Gray Eagle
The Gray Eagle measures 28 feet (9 meters) long and has a wingspan of 56 feet (17 meters).
Its base configuration has a top speed of 167 knots (192 miles/309 kilometers per hour) and a service ceiling of 29,000 feet (8,839 meters).
Users can integrate the drone with air-to-air or air-to-ground missiles.