General Atomics Aeronautical Systems (GA-ASI) has conducted the first flight of its new heavy-fuel (diesel) engine for the MQ-1C Gray Eagle remotely piloted aircraft. The recently disclosed flight took place at the company’s El Mirage test airfield in California on May 9. The company plans to start qualification tests for the engine later this year.
From the start of the MQ-1C program, the U.S. Army specified a heavy-fuel engine so that the fleet could employ the same fuel used in land vehicles. The new powerplant—the 200-hp Heavy Fuel Engine (HFE) 2.0—replaces the current 180-hp unit. It is a feature of the Gray Eagle 25M now under development. This version is destined for the U.S. Army’s future Multi-Domain Operations, with an open system architecture, new sensor capabilities, and new communications systems, including Ka- and Ku-band satellite links.
GA-ASI began the program in 2016 with the goal of developing a more reliable and durable engine than the Thielert Centurion that powered the initial Gray Eagles. The program also sought to address diminishing manufacturing source issues. Company affiliate General Atomics Europe worked with UK propulsion innovator Cosworth to develop the engine, while GA Electromagnetic Systems designed dual-brushless generators that deliver 50 percent more power for payload operations. The generators contribute to a reduction in field maintenance and a 40 percent extension in time between overhauls compared with the current engine.