Abstract: A pair of turbofan engines are cross connected such that during normal-mode operation horsepower can be shared by the respective cores, and when one engine core becomes inoperative the fan of that engine can be driven by the turbine of the operative engine to thereby maintain a substantial thrust output. In order to balance the respective thrust outputs, variable inlet guide vanes are controlled to decrease the fan mass flow in the operative engine and increase the fan mass flow in the inoperative engine. The variable inlet guide vanes are so constructed as to only partially span the fan duct so as to not appreciably affect the airflow to the core when the inlet guide vane angle setting is altered to allow the core to thereby retain a high level of supercharging during this operational period of maximum power demand.

Abstract: A propulsion system for use primarily in V/STOL aircraft is provided with a variable cycle, double bypass gas turbofan engine and a remote augmenter to produce auxiliary lift. The fan is oversized in air-pumping capability with respect to the cruise flight requirements of the remainder of the engine and a variable area, low pressure turbine is capable of supplying varying amounts of rotational energy to the oversized fan, thereby modulating its speed and pumping capability. During powered lift flight, the variable cycle engine is operated in the single bypass mode with the oversized fan at its maximum pumping capability. In this mode, substantially all of the bypass flow is routed as an auxiliary airstream to the remote augmenter where it is mixed with fuel, burned and exhausted through a vectorable nozzle to produce thrust for lifting.

Abstract: A flight maneuverable gas turbine exhaust nozzle is provided with cooperating variable internal converging-diverging flaps to provide area control. A flap downstream of the converging-diverging flap provides flight maneuver vectoring as well as external exhaust expansion control. A vertical take-off and landing capability is provided by deployment of a rotating bonnet-type deflector which diverts the exhaust stream downward around one side of the exhaust nozzle. The nozzle throat rotates with the deflector to produce efficient turning of the exhaust stream.