APU - Shutdown Essential Mode

Gulfstream GVII

Eddie sez:

If you see APU Essential that means the APU is running while in flight and a fault is detected which normally would have caused an automatic shutdown if it were not in essential mode. If you need the APU, keep it running. Otherwise, shut it down. Once it is shut down, it will not restart.

Everything here is from the references shown below, with a few comments in an alternate color.

Last revision:


AFM Procedure

[AFM, §03-03-30]

Corrective Action

  1. If the APU is not necessary for continued safe flight and landing, or if after landing:

    1. APU STOP

    2. APU MASTER OFF (RPM less than 5%)

    3. APU RPM / EGT Monitor for 5 minutes

Gulfstream GVII-G500 Airplane Flight Manual, Revision 4, August 29, 2019