Nice job, Delta Crew

[pilotyip]

I remember in training they said don't crank the APU or it could drain the battery and the response from the instructor was always fly with the APU running. (jokingly sort of)

Our DC-9 COM says start APU if you loose one generator, so were both gens drop dead same time

 

[bafanguy]

I remember in training they said don't crank the APU or it could drain the battery and the response from the instructor was always fly with the APU running. (jokingly sort of)

If you're referring to the DC9/MD80(ish) family, there's dead bus sensing providing that, if both AC busses are lost with the ground shift in the flight mode, the battery is prevented from powering the APU starter. If cold soak doesn't get in the way, the APU will windmill start.

Took a quick look at the B717 manual to see if it has the same dead bus sensing but couldn't find it...got bored...gave up looking. My attention span is short these days.

However, it wouldn't surprise me to find the same dead bus sensing is provided on the 717. A good idea is usually a good idea over time.

And, yes, lose one GEN ? Start the APU.

 

[Junkflyer]

Lose one, start the ape. Lose both and the risk is that if the apu does not start, you've lost a lot of the remaining battery power. Its not in the qrh to start the apu.

 

[bafanguy]

You mean that in the 717 QRH the procedure doesn't call for starting the APU if one GEN is lost ?

 

[Junkflyer]

Lose one and you start it.

 

[Muskycat]

Lose two and start a thread.

 

[wood pecker]

I think it was a lawyer thing to protect Boeing if I remember. While in class someone asked why not to start APU after a dual gen failure. Instructor made a call and said that he was told an APU crank could deplete the rest of the batt so not to. That led to him saying that is BS just fly w the APU on all the time. Heck even the CRJ had an ADG (little air driven turbine would pop out).