释义 |
auxiliary power unit
auxiliary power unit n (Aeronautics) an additional engine fitted to an aircraft to operate when the main engines are not in use Translationsauxiliary power unit
auxiliary power unit[ȯg′zil·yə·rē ′pau̇·ər ‚yü·nət] (aerospace engineering) A power unit carried on an aircraft or spacecraft which can be used in addition to the main sources of power. Abbreviated APU. auxiliary power unit (APU)A power generation unit for operation of systems like hydraulic, air conditioning, electrical, and avionics. It may provide AC (alternate current) or DC (direct current) supply. The APU is normally used prior to starting the aircraft and for testing systems on the ground. In rare cases, it can provide some thrust in an emergency. Ground auxiliary power units provide current for starting engines. See airborne/auxiliary power unit.See APU See APU |