View Full Version : Whining MD-80
BayAreaLondoner
30th Aug 2002, 22:01
I flew on a Continental MD-80 last night and was seated over the wing.
Just before push-back a loud whining started. I thought it might be the APU and would stop after engine start but it didn't and continued until we'd taken off, climbed-out and retracted the flaps.
Then before landing it came back possibly before flaps were extended.
Wondering what it was - hydraulic pump of some sort?
Palma de Mallorca
30th Aug 2002, 23:43
Could it possible have been a (frequent) seal lapse in one of the overwing emergency exits, as opposed to a mechanical noise?
Incidentally, a harmless occurence.
Bayarealondoner,
That is the auxillary hydraulic pump. F/O switches it on before push back, on request from F/A to enable her to raise backstair. Goes off, and goes on again after start up, until aircraft has been cleaned up in the climb. On approach goes on again, until after parking.
Gives 3000 psi as opposed to normal 1500 psi when off (in flight).
Makes a blo*dy noice, especially when engines are quiet, and much worse in the back of the cabin.
Rgds Zico
BayAreaLondoner
4th Sep 2002, 00:46
Pprune rules... Thanks for clearing that up!
The AUX pump is located in one of the wheel wells if my memory serves me right. Probably the right one since it's connected to the right system. It's always drawn in the center or to the right on system charts.
Don't have technical drawing here right now... :D
BayAreaLondoner
4th Sep 2002, 22:53
I was pretty much sitting right over the right wheel well.