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which engine to cut off before using GPU

Posted: Sun Jan 06, 2019 8:28 am
by hawjl
When APU is not allowed or for the purpose of cut down the working cycles of APU, crews may need to keep one engine running until the ground staffs connect the GPU to the aircraft(normally power unit attached to the gate). My concern is which engine to cut off first? Some say left engine(engine one ) because it’s the some side with the gate, other say the right one because for boeing type, the plug is located on the right side of the nose and shut down the right one can lower the risk of ground staff. Any one know is there any artical or manual related to this issue, or any specific requirement demanded by indivisual airport? THX.

Re: which engine to cut off before using GPU

Posted: Sun Jan 06, 2019 3:05 pm
by mmo
It should be specified in the specific airline SOP. I can't think of any airport I have flown into which specifies a specific engine to shutdown. My experience is on twin engine aircraft I have flown, the right (2) engine which is shutdown. Cargo doors can be opened, servicing doors can be opened.

Re: which engine to cut off before using GPU

Posted: Wed Jan 09, 2019 5:02 am
by T54A
We don’t cut any on either our twins or quads. Pull into the bay, wait for GPU to be connected, cut the motors. If you wanted to be super efficient on the A340 you would cut the inboard two engines and on the A330 you would Eng 2.

Re: which engine to cut off before using GPU

Posted: Wed Jan 09, 2019 5:21 am
by fr8mech
Whichever engine is specified by your operator.

As I recall, the Left or #1 Engine (A300) is shutdown on our twins, the #1 & #3 on our MD',s, #1,#2 & #3 on our 747's.

Re: which engine to cut off before using GPU

Posted: Thu Jan 10, 2019 9:48 am
by Tristarsteve
Also read the airport and airline rules. Here at ARN the handling agents will not approach an aircraft with the engines running. They will wait behind the yellow line until the anti-collision lights are off. If you want them to approach, you must talk on the radio and agree the rules.

Re: which engine to cut off before using GPU

Posted: Fri Jan 11, 2019 6:31 pm
by DL777200LR
I’ve usually seen the #1 eng be shut down first since the jetbridge has to be connected which sometimes is to the L2 door that is right next to the #1.

Re: which engine to cut off before using GPU

Posted: Sat Jan 12, 2019 3:12 pm
by glen
It can also depend on the situation. If we taxi-in on one engine with the A330 we shut down ENG2 during taxi in order to have the Green and Blue Hydraulic Systems pressurized by ENG1. So while waiting for GPU at the gate, Engine 1 is running.
On the other hand, if we taxi in with both engines we shut down Engine 1 first at the gate while wating for the GPU. This eases the access from the left hand side.

Re: which engine to cut off before using GPU

Posted: Sun Jan 13, 2019 2:04 pm
by B777LRF
This has been the topic of many discussions, where different points of view have collided. In a previous life our department tried to align the practices of just two airlines operating the same aircraft type to the same airports. One of them would taxi in on two engines and shut down no. 2 whilst waiting for the GPU to be connected. The other would turn on the APU during taxi in, and shut down both engines upon reaching the stand.

Over the cause of many, many, many meetings, conference calls and emails, neither of the airlines were willing to change their method in favour of the other. Our department was in the middle saying "guys, we don't care which method you use as long as you use the same one". Eventually my boss bent the ear of a very senior person, who in turn gave the airlines a week to sort out their differences and reach a consensus. Which they did, and the procedure was "APU on, engines off when reaching stand", and was chosen solely on the basis of ramp worker safety.

Imagine the fun we had, when we used that decision to influence roughly 50 other airlines around the globe to follow a single standard! Some were easy, some were damned near impossible to work with. In particular two airlines, one carrying a D-prefix and the other a N- to their registrations, were ginormous pains the the rear end.

Re: which engine to cut off before using GPU

Posted: Sun Jan 13, 2019 5:04 pm
by FlyHossD
mmo wrote:
It should be specified in the specific airline SOP. I can't think of any airport I have flown into which specifies a specific engine to shutdown. My experience is on twin engine aircraft I have flown, the right (2) engine which is shutdown. Cargo doors can be opened, servicing doors can be opened.


+1. In my experience on twin engine aircraft, we always shut down the #2/right engine (737, 757, 767) before approaching the gate except in slick conditions. In the 727, we shut down the #3 engine.

Generally, it was my operator's preference to shut down the outer engine - away from the Jetway - 3 or more minutes after landing and to start the APU before reaching the gate. Once parked at the gate, the #1 engine would be shut down with the APU assuming the pneumatic and electrical load. If the APU was inop, we'd leave the #1 engine running until the ground power was connected and turned on.