View Full Version : "Elevator Trim" on 747-100

25th Jul 2002, 18:24
Just found an old photo of a Polar -100 and on the center pedestal (P8) at the rear left, fwd of the aileron trim switches there is a elevator trim gauge, don't think it was functioning though.
Any Ideas on it's obvious function as there were no trim switches and I don't remember being able to trim the elevators.
Plus unrelated to elevator position indicator.

26th Jul 2002, 00:06
Sure it's not an old EPR ssytem of some sort? That's where the test system & panel for some of them normally sits.

26th Jul 2002, 09:49
Nuh it Says " elevator trim" and has +2/-2 units.

26th Jul 2002, 14:58
*scratches head* ...
Nah, sorry, don't know!
I've flown a few -100's (all ex-JAL) and none of them had anything like that.

27th Jul 2002, 18:13
Pan Am aircraft had these. They were originally used in conjunction with the INS for fuel savings on long haul flights. On the INS you would select Wind/Hold and it would then show acceleration/deceleration in milli-Gs; you could then use the trim and the throttles to maintain zero elevator displacement and constant speed throughout the the flight. A poor man's PMS I guess.