ATR 72 Drift Down procedure
 

Hello everyone,

I have quite a few doubts in ATR 72-500 procedures and systems, I hope
pilots in this forum can help me.

1.Can anyone please explain the difference between Drift down ceiling and single engine gross ceiling? If they are different, during drift down procedure do we level off at drift down ceiling or single engine gross ceiling?

2. What happens when the PUMP push button in the fuel panel is switched off during flight? I understand that the push button not only controls the electric pump, but also the motive flow valve. So by switching it off will the engine shutdown?

Thanks

I believe that the one-engine inoperative ceiling is a service ceiling with a ability to still climb at a certain minimum rate while a driftdown ceiling is an absolute ceiling with zero-climb capability.

If terrain and fuel are not limiting, why not level off at an altitude below maximum which could be difficult to maintain.