Quoting Kimberlyrj (Reply 2): Is it not good practice to allow the APU to run for a few minutes before it starts powering the aircraft etc, and on the other hand, when the engines are started (and powering the aircraft) is it not good practice to leave the APU on for a few minutes – I am sure I heard this was done in connection with the reduction of ware on the APU unit and its components? |
Quoting DALMD88 (Reply 3): Usually the apu gen comes online as soon as the apu is running stable. As for pnumatics as soon as the pressure is up you can open the valve. For shutdown I let the temp stablize after shutting off the air and then select off. The apu goes through a cooldown cycle all by it's self. |
Quoting FlyinTLow (Reply 5): On the A320, the GEN is on as soon as the APU is running, but it is not connected to the aircrafts electrical system yet. |