Battery start A320

[Thunderbug]

Recently operated an aircraft that had the APU GEN U/S. Air Bleed OK.

We wondered if we would be able to start the engines without having a GPU available and the only electrics being the battery until an engine generator cut in?

Alternatively could we do the engine start with batteries and an air start unit?

My previous type (757) had a published battery start procedure, we were unable to find any such procedure for the A320.

Any ideas?

Tbug

[mokilu]

According to MEL, if the GPCU is also inoperative engines can not be started.


Therefore, I think that GPU is required to start unless you dispatch according last option.

Regards

[Thunderbug]

Mokilu

Good spot...... it is right there above the MEL entry

NOTE:
When GPCU and APU Generator are both
inoperative, engines can not be started.

Thank you very much
Tbug

[Microburst2002]

interesting situation.

on batteries only and on ground, can the FADEC be supplied?

I think there is one of the EIUs that is supplied by batteries. But the FADEC is selfsupplied when engines running and by the AC network when not running on the ground. just quick thinking without refering to any documents, right now. Am i right?

[Checkboard]

Can't start the engines without AC power. Can't start the APU without battery power.

[Microburst2002]

that's right.

and yet, I was wrong and it happens that FADECs and EIUs are supplied by DC current. one channel of eng 1 FADEC and EIU 1 are supplied by DC BAT current, and one FADEC and EIU2 by the DC ESS. Both buses are supplied by batteries on ground with the BAT pushbuttons in AUTO.

Oh wait! but ignition is AC. There is no AC on ground, unless they do a pushback at more than 50 kt

[Microburst2002]

not sure. in the FCOM 1 says static inverter during RAT extension, but probably that includes on ground and bat only, too.

anyway, as you say, you cannot start an engine without any instrumentation to monitor the start up.