Shutting down engines after flight

[CaptainSandL]

After many years on type (737) it was recently mentioned to me on a line check that the company SOP on arrival was to shut down each engine one at a time, so as to be able to monitor their shutdown. I was still in the habit of shutting them all down together as a hangover from my previous airline.

Whilst I am perfectly happy to abide by the wishes of my present employer I am curious which way is the more usual (on any a/c type) and if there is any real advantage to shutting down the engines one at a time. I would have thought that shutting down the engines was a very low risk exercise and also that any abnormalities would be better highlighted by viewing all engines parameters together ie by playing “spot the odd one out”.

Which way is more common and is there a good reason for doing it that way?

S&L

[ratarsedagain]

On our Airbus fleet, the sop is to shut down one engine, wait for the 'clunk' of the electrical transient, and then shutdown the other. This prevents memorisation of the wrong fuel used value.
Hope this helps!

[ftrplt]

have seen some shut down the left first and wait for power transfer before shutting down right. (2 eng obviously)

If the APU power doesnt kick in after shutting down the left you can leave the right running and have the option of still bringing in the aerobridge if its a long wait for external power

[Terraplaneblues]

That SOP would also prevent the simultaneous shutting down of engines becoming habitual.
On 75/76 and subsequent the fuel controls are deliberately separated so you can't operate both at the same time with one hand.

[alexban]

on the 737 the apu won't kick in automaticaly,so no need to wait for the power to be transfered before shutting the other engine.
What are you monitoring during shutdown,except that it shudowns,and the n1?
I shutdown both engines together.Different systems,electrical and a/c already on the apu ,during taxi in checks.

[LEM]

From a philosophycal point of view, I think Terraplaneblues has got a point here.
In a cockpit, we should never move more than one switch at a time (how many of us do this with pitot heat in the after start? ;) ).

But also Chris has got a point, by comparing the smoth rolldown of both engines together it could be easier to spot an anomaly...

[blackmail]

hello every one,

tecnically there is no problem shutting down both engines together, but there are some other considerations:
on b737, i always shut down rh engine first for 2 reasons:
1] for safety reason when parking at the gate & waiting for a gpu plug in. sop for my airline specify no apu if a gate+gpu is avail after landing.

2] if apu was started but not put on busses, to avoid putting every one(momentarily) & litterally in the dark at night.