General Atomics Aeronautical Systems Inc. (GA-ASI) has successfully completed qualification trials for its new 200-horsepower heavy fuel engine, designated HFE 2.0, for the Gray Eagle 25M unmanned aerial system at a test site in El Mirage, California. The development of the HFE 2.0 engine marks a significant advancement, offering a 40 percent increase in the service life of the drone, as well as a 50 percent boost in power for its mission payloads. This improvement is aimed at enhancing the drone’s maintenance-free and low-sustainment capabilities, which are critical for meeting user demands in complex multi-domain operations.
The qualification trials lasted three weeks and were conducted in accordance with the US Federal Aviation Administration’s (FAA) primary performance standards for engines intended for commercial applications. GA-ASI highlighted that the HFE 2.0 engine underwent extensive testing in the 18 months prior to the FAA evaluation, which included simulating high-stress flights of varying lengths, totaling 200, 400, and 651 hours. Additionally, the engine completed 50 hours of trials to assess its overall operational boundaries, showcasing its readiness for deployment.
Following these successful tests, the HFE 2.0-equipped Gray Eagle is slated for a separate qualification process under the US Army’s oversight. This step is essential for authorizing the use of the new engine across the Army’s existing fleet of Gray Eagle Extended Range drones, where it is set to replace the older 180-horsepower engine currently in use.
David Alexander, President of GA-ASI, expressed his satisfaction with the results of the test program, stating, “This test is the culmination of the extensive durability and flight test program for the HFE 2.0 engine. 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.”
In recent developments, GA-ASI’s Gray Eagle is positioned as a potential candidate to serve alongside the US Army’s Future Attack Reconnaissance Aircraft (FARA) program. This initiative, currently on hold, aims to develop a modern drone-helicopter team equipped with enhanced radar, imaging solutions, and communication relays to bolster vertical lift capabilities.
In another milestone, GA-ASI completed the maiden flight of the Gray Eagle 25M in January 2024, which followed a noteworthy $389 million contract awarded in December 2023 for its production. During October 2023, the company initiated manufacturing the latest configuration of the Gray Eagle, which includes an advanced sensing capability capable of detecting threats at distances of up to 50 miles (approximately 80 kilometers). Furthermore, one year prior, GA-ASI successfully tested the drone’s next-generation flight computer featuring improved memory, processing power, and a high-speed ethernet interface.
The Gray Eagle unmanned aerial system itself is a robust platform, measuring 28 feet (9 meters) in length and boasting a wingspan of 56 feet (17 meters). In its base configuration, the drone can achieve a top speed of 167 knots (192 miles or 309 kilometers per hour) and operates with a service ceiling of 29,000 feet (8,839 meters). Its versatility allows it to be integrated with various armaments, including air-to-air or air-to-ground missiles, broadening its operational capabilities in military applications.
