Engine Start

Gulfstream GVII

Eddie sez:

The FADEC will protect you from most start anomalies and you are pretty much a spectator during a ground start. One of the few exceptions is for a starter valve that has failed open. For that, you have this: Start Valve Fail Open on Ground.

A good rule of thumb for a normal acceleration is that TGT/10 should be greater than N1, if not you will get a depulse (sharp reduction in fuel) as the FADEC attempts to keep the engine start viable.

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

Last revision:

20190603

AFM Procedure

[AFM, §02-03-10]

  1. PARKING BRAKE / Pressure . . . Set / 2000 PSI minimum
  2. Bleed Air Pressure . . . Verify 22 PSI minimum
  3. POWER LEVERS / T/R LEVERS . . . IDLE / Down
  4. FUEL CONTROL (Right) . . . RUN
  5. NOTE

    If TGT is greater than 120°C the FADEC will motor the engine and inhibit fuel flow until TGT decreases below 120°C.

    If a sub-idle stall condition is detected, a rapid increase in TGT may occur with a delayed increase in N2. The FADEC will initiate a fuel depulse, as the TGT approaches 750°C, to prevent an exceedance. During the fuel depulse, the FADEC will command a near zero fuel flow to clear the stall and then progressively command higher fuel flow to re-accelerate and start the engine.

  6. ENG START . . . PRESS
  7. When is the engine confirmed started? You can look up to the fuel panel and see when the alternate fuel pumps are on, that's a good clue. But an even better one is to notice when the red arc on the TGT dial changes scale and becomes smaller.

    1. Hyd Pressure (Right) . . . Verify 3000 PSI
    2. PTU Pressure (Right) . . . Verify 3000 PSI
  8. FUEL CONTROL (Left) . . . RUN
  9. ENG START . . . PRESS
    1. L / PTU / R Hyd Pressure . . . Verify 3000 / 0 / 3000 PSI
  10. MED / Service Doors . . . Closed
  11. APU BLEED AIR / APU . . . As required
  12. CAUTION

    THE SPEED BRAKE HANDLE MUST BE FULLY SEATED IN THE RETRACT DETENT TO PREVENT INADVERTENT EXTENSION.

  13. Flight Controls (Pilot) . . . Check
  14. SEAT BELT / NO SMOKE PASSENGER WARNING . . . ON
  15. NOSEWHEEL STEERING POWER . . . ON

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

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