ELICOTTERO COMPOSITO E GRUPPO MOTOPROPULSORE PER ESSO

A compound helicopter shown in FIG. 1 of the drawings has wings 12 in addition to a helicopter rotor 14 and has twin powerplants 16 each including a low pressure compressor 18, a core engine 20, a power turbine 22 driven by the core engine and connected through a gearbox 32 to drive the helicopter rotor, and a variable area final, propulsion nozzle 24 which receives the exhaust from the power turbine. Augmentor wing flaps 28 are provided on the wings and fed with air from the low pressure compressor for providing additional lift and thrust from the wings. In operation, at take-off the nozzles 24 are fully opened and all of the power produced by the power turbines 22 is used in driving the helicopter rotor for producing lift. In addition, the augmentor wing flaps 28 are directed downwardly to provide lift. For forward flight the nozzles 24 are closed down, reducing the power to the rotor and slowing it down, while at the same time generating forward thrust. Additional forward thrust is derived from the flow of compressed air through the augmentor wing flaps 28.