OPERATING AUXILIARY POWER UNIT DURING OFF-NOMINAL PROPULSION SYSTEM OPERATION

摘要

An aircraft system includes a component configured to operate with a minimum power demand. The aircraft system also includes an auxiliary power unit including an engine. The auxiliary power unit is configured to power the component and to operate the engine in a plurality of operating modes including a power mode and a standby mode. The auxiliary power unit generates a first power output at least equal to the minimum power demand during the power mode. The auxiliary power unit generates a second power output less than the minimum power demand during the standby mode.