Power systems developer Rolls-Royce is to supply engines for the US Marine Corps and Air Force V-22 aircraft.The $598m contract with the US Department of Defense could see Rolls-Royce supply 268 AE 1107C engines over a period of five years. In the first year, Rolls-Royce will deliver 70 engines valued at $151m, after which the US Department of Defense has the option to extend the contract arrangement on a year-by-year basis for as further four years.Rolls-Royce is the sole manufacturer of the engines for the V-22 and has already delivered 550 AE 1107C engines to the US Department of Defense. JH