FSX - If I start the APU from the Cold and Dark without turning on the Left DC Fuel Pump, the APU Logic automatically turns this pump on. Should the associated PRESS Light not turn off with turning the APU start switch to ON, as the pump starts and delivers fuel, ie fuel pressure and flow is available? With the CS 757, the pressure light only goes out when the APU is running.

FraPre wrote on Apr 21^st, 2019 at 4:11pm:


You’re confusing AC fuel pump with DC fuel pump. The DC fuel pump (there’s only 1) has no indicators or buttons. What happens is:

1. Cold and dark, battery on, standby bus auto, APU selector to start/on.
2. DC pump immediately comes on, all 6 AC fuel pump PRESS lights should be illuminated since there’s no AC power.
3. APU is fully started and you have AC power, now the FWD left AC boost pump PRESS light extinguishes, and the DC pump (which you can’t even tell it’s happening) turns off.