Originally Posted by
Bumblebee
There should be no delay in shutting down the engine, in order to minimise risk of a roll forwards in the event of a brake failure, or to ground crew approaching the aircraft - both high risk, and not without fatal precedent.
Point being.. it doesn't really matter if the Y Elec pump is switched off before, simultaneously or after PF has shut down ENG 1, but many think that the order it's presented in the FCOM Normal Procedures means it has to be done before the Engine is shut down. May be better to consider the PF setting the parking brake is a trigger point for the PM to begin their shutdown flow..
Take a look at the Task Sharing: PRO-NOR-TSK 00024929.0004001 "At parking position:"
Hi,
beg to differ on the above.
The OETA is a supplementary procedure even though nowadays it is often embedded in normal SOPs within the airlines (including mine) but the actuation logic remains the one of a supp procedure.
There is no reason why You would want to shut down engine N1 "immediately" once at parking position. The risk or roll forward is mitigated by the the proper application of the parking brake (
Safe aircraft parking) and the ground staff is trained not to approach the aircraft till the beacon light is switched off. Furthermore, if operating with APU inop you would have to wait till ground power is connected to shut down Engine 1 (on a side note some airports do require the port engine to be off for the ground crew to connect the external power so OETA would not be possibile if operating without APU). Bottom line is, many occasions where you could find yourself at the gate with one engine running for a handful of seconds in completely normal operations.
On the other hand, not respecting the sequence Y ELEC PUMP OFF
then ENG 1 Shutdown is an incorrect application of a supplementary procedure.