General Atomics Aeronautical Systems has completed the first flight of its Gray Eagle 25M uncrewed aerial vehicle (UAV), a modernised version of the MQ-1C Gray Eagle currently in service with the US Army.

The San Diego-based UAV manufacturer announced the milestone flight on 25 January, noting the sortie took place in December at the company’s flight complex in El Mirage, California.

General Atomics was awarded a $389 million contract from the army on 1 December to fund the GE-25M flight-test programme.

Grey Eagle 25M

Source: General Atomics Aeronautical Systems

As part of modernisations to its Gray Eagle uncrewed aerial vehicle, General Atomics developed a new engine it says will be more reliable, more durable and address diminishing sources for heavy aviation fuel engines

The MQ-1C is a multi-role, long-endurance UAV capable of carrying a variety of intelligence, surveillance and reconnaissance payloads and up to four Lockheed Martin AGM-114 Hellfire air-to-ground missiles.

As part of its Gray Eagle modernisation effort, General Atomics developed a new engine, which the company says will be more reliable, more durable and address the problem of diminishing sources for heavy aviation fuel engines and components.

The new powerplant, dubbed the Heavy Fuel Engine (HFE) 2.0, will replace the endurance aircraft’s current propulsion system. General Atomics has been developing the HFE 2.0 since 2016.

“The design effort was focused on reducing field maintenance and extending the time between engine replacement by 40% over the current engine,” the company said in June 2023, following the first flight of the engine on an existing Gray Eagle.

In addition to providing more horsepower, the HFE 2.0 will deliver 50% more electrical power for new payloads and onboard systems.

The new powerplant will also offer maintenance advantages, extending the time between engine replacement by 40%, as compared to the existing propulsion system.

“The new engine, gearbox and generator design decreases major maintenance actions and virtually eliminates the need for overhaul,” General Atomics says.

The GE-25M test programme is also certificating an improved flight computer that will provide a fivefold increase in processing speeds and 80 times the amount of data storage, compared to existing Gray Eagles.

In addition to allowing the fielding of more powerful sensors, those improvements will also support the US Army’s push to incorporate autonomy into its aerial systems.