Patent attributes
A vertical take-off and landing aircraft using a hybrid electric propulsion system includes an engine, a generator that produces electric power using power supplied by the engine, and a battery that stores the produced electric power. A motor receives the electric power stored in the battery and electric power produced by the generator but not stored in the battery and provides the power to a thrust generating apparatus. A controller selects either silence mode or normal mode, and determines the amount of electric power stored in the battery and the amount of electric power not stored in the battery from the electric power supplied to the motor. In the silence mode, the controller supplies only the electric power stored in the battery and controls a duration by adjusting output power of motor. In the normal mode, the controller supplies electric power not stored in the battery.
