Rolls-Royce RB3011

The Rolls-Royce RB3011, previously designated RB2011, is a prototype propfan or open rotor engine from Rolls-Royce plc, designed for aircraft of 180 to 300 passengers such as the Boeing 737 or Airbus A320. It has two contra-rotating rotors outside the nacelle, either at the front as a tractor or at the rear as a pusher, driven from the engine shaft through an epicyclic gearbox, with the forward rotor larger than the rear to avoid problems with eddies from its tips. The design was renamed because employees kept confusing 2011 with the expected service entry date. Rolls-Royce hoped to cut fuel consumption by up to 30 percent against a normal turbofan, with noise the known drawback; it was considered for the Irkut MS-21 in late 2008 and tested in wind tunnels at DNW in the Netherlands.