Left Main AC Bus Fault

Gulfstream GVII

Eddie sez:

There isn't much here other than the AFM procedure. I'll give this more thought when I get a chance.

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

Last revision:

20191019

AFM Procedure

[AFM, §03-04-30]

Displayed CAS and CA Messages

L Main AC-Volts

System Impacts

With RAT Generator on the following systems are impacted:

  • Autopilot: Not available.

  • Autothrottle: Not available.

  • ADS: ADS 1/2/3 not available for selection.

  • FD: Not available.

  • FGP: Airspeed and altitude inputs not available.

  • TCAS: Not available.

  • XPDR: Mode C not available.

Corrective Action

  1. AC Power Synoptic Page . . . Verify

  2. CAUTION

    THE EMERGENCY AC BUS IS NOT POWERED IN THIS CONFIGURATION. THE EBHA AND UPS BATTERIES ARE BEING DISCHARGED.

  3. RAT . . . Deploy

  4. NOTE

    Airspeed should not be reduced to less than 200 KCAS until it is necessary to land so as to ensure proper RAT operation.

    The RAT will power the Emergency AC, L ESS DC and R ESS DC busses.

  5. RAT GEN . . . Verify On

  6. EMERGENCY POWER . . . ARM

  7. Airplane . . . Land at nearest suitable airport

  8. Final Approach

  9. NOTE

    RAT GEN will drop off line below approximately 200 KCAS. To prevent the RAT GEN from repeatedly shedding the load and then resupplying electrical power, the RAT GEN must be selected OFF prior to decelerating to less than 200 KCAS.

    1. FLAPS . . . 20°

    2. RAT GEN . . . OFF (above 200 KCAS)

    3. Landing Gear . . . Down

    4. FLAPS. . . DOWN

  10. If a go-around is required:

    1. Once at greater than 200 KCAS:

    2. (1) RAT GEN . . . ON


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

Gulfstream GVII-G500 Production Aircraft Systems, Revision 3, July 15, 2019