A320...APU inop Vs Parking Procedure (Engine Shutdown)

[kuwait340]

Hello...

it happend to me some times that we dispatch without APU.

my question is...

when you stop at the gate,what is the proper sequence of shutting down the engines.

the procedure i have seen it with most pilots : they shut down engine no.1 and then wait to connect EXT PWR then shut down no.2 .

but this is not written any where...(at least i didn't read it any where)

but my thought is...if you shut down no.1 first you will lose the green hydraulic system pressure...so you don'y have the normal braking system.

you will still have the alternate braking but you have to select NWS switch off...in case you need it.

actually it happened to me couple of days ago...we shut down no.1 then we had to wait 10 mins till they brought a good ext pwr unit.and i was looking at the ECAM hyd page...and the green system px was down...

thanks

[Clarence Oveur]

Does it matter once the parking brake is set?

[PHAROH]

for parking & securing u need only the Brake accu press.
u can ref. to one eng taxi arrival in supplementary tec. to answer your thoughts regarding eng 2 shutdown first .

[kuwait340]

hello...

that is correct ,only the accumlator px is required.

but my concerns were : what if you lose the accu px...and you have already shut down eng no.1 .

i know i am exaggerating here...but i just wanted to do the correct procedure taking into account the worst case scenario...and also to avoid following other fellows who have no idea but to do what they have seen before and to repeat even if it is wrong .

PHAROH thank you for directing me to the right direction.

once again ...thanx

[Mäx Reverse]

I prefer to shut down no.1 in this case.

As stairs/jetways are approaching from the left (engine clearance on the 319 is pretty slim) and these days nobody gives a damn about the beacon light.

If you really lose your yellow accu , just put the ENG MASTER 1 back to ON and you have the GREEN System pressurized via the PTU.:ok:

Cheers, MAX

[Clarence Oveur]

Would losing the yellow accu matter once the parking brake is set?

[shortfuel]

The first aspect of your question:

I can only invite you to refer to your company SOP's but as for Airbus SOP's:
"If APU is not available, set EXT PWR to ON, then set ENG MASTERS to OFF" : 3.3.25

About BRAKE ACCU PRESS:
"The ACCU PRESS indication must be in the green band. In case of low accumulator pressure, chocks are required before engine 1 shutdown"

If you lose your BRK ACCU PRESS while Parking Brake is set, different cases:

1/ You have pressure in the Green (ENG running): release Parking BRK et restore braking with pedals
2/ Your Green pressure is at 0: hope that you have chocks in place or that you are on a very flat surface, call for assistance.

This is not applicable to all A320 family A/C as last A/C + modified A/C have a slightly different interaction between PRK BRK handle position and pedals braking (i.e on some MOD A/C, you can use your pedals braking even if parking brake is ON)

So long'

[Thunderbug]

Does the PTU still work in this situation?

T'bug

[kuwait340]

thanks everyone for your kind inputs...

Thunderbug ... i was looking at the ecam hyd page the other day when we shut down eng no.1 and no.2 was running as we were waiting to connect the ext pwr...and i can tell that what i have seen is that the green system was not pressurized ...i think it is may one of the conditions that the ptu is inhibited (look at fcom 1.29.10 p1 at the bottom ).