The HFE 2.0 offers a 40% increase in service life compared to its predecessor, enabling longer maintenance-free operational periods. Designed to power the modernised Gray Eagle 25M Unmanned Aircraft System (UAS) for Multi-Domain Operations (MDO), the engine provides the horsepower and electrical power necessary to meet demanding operational requirements.
“This test is the culmination of the extensive durability and flight test program for the HFE 2.0 engine,” said GA-ASI President David R. Alexander. “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.”
The three-week qualification test adhered to the Federal Aviation Administration’s endurance test standards (FAA 14 CFR 33.49) for commercial aviation engines. Over the past 18 months, the HFE 2.0 underwent rigorous durability testing, including 2,450 full-power cycles and extended test profiles totalling 1,251 hours. It also completed 50 hours of flight testing across its operational flight envelope.
The engine was developed in partnership with global high-performance engine leaders and supported by propulsion innovator Cosworth. General Atomics Electromagnetic Systems contributed by designing the dual brushless generator, which reduces maintenance and delivers over 50% more electrical power. This upgrade supports new payload capabilities essential for the MDO mission.
Following the FAA endurance test, the HFE 2.0 will proceed through the U.S. Army certification process. Once certified, it will be authorized for use on GA-ASI’s Gray Eagle Extended Range (GE ER) UAS fleet, replacing the existing 180-horsepower engine nearing the end of its service life. The engine is also central to the U.S. Army-funded Gray Eagle 25M modernization program, designed to meet future operational needs.
