UK engineering company Cosworth has been selected by the US Navy for the first of three phases of the two-year ultra endurance unmanned air vehicle (UE-UAV) heavy fuel engine technology development programme.

Cosworth plans to increase the power output of the 3hp (2.23kW) AE-1 engine, which weighs 3.5kg (7.7lb), during the four month-long first phase, as well as improving its fuel efficiency and reducing its noise levels. The power output increase, to the US Navy's target of up to 10hp, is expected to require an increase in the AE-1's number of cylinders from one to two. The three phases include extensive ground and flight test evaluations of heavy fuel engines to prove their technological readiness.

Cosworth's aerospace and defence business unit leader Simon Corbyn says: "Development of a range of heavy-fuel UAV engines is a key requirement to alleviate the military's dependency on multiple fuels. In contrast heavy fuels such as diesel and jet fuels are routinely supported and significantly reduce risk."

If successful the engine will be used for the US Navy's Small Tactical Unmanned Aerial System, Tier Two class UAV programme. In the second and third quarters last year the AE-1, fuelled with diesel, was used to power the Arcturus T-16 UAV in test flights over California as part of the US Marine Corp's Tier Two tactical UAV concept demonstration programme. In rig tests at Cosworth's Northampton head office the AE-1 used a variety of heavy fuels.