Trim Stuck Full Nose up

[jim34285]

Trim is stuck full up...trim handle turns counter-clockwise but won't turn clockwise at all.
Does anyone have a trim system diagram for a BC-12D? Would you email it to [email protected]?
Has anyone had a similar experience and can offer suggestion(s)?

Jim

[Howard Wilson]

Re: Trim Stuck Full Nose up

Hi Jim, click on the search button above and search on 'trim system' you'll find lots of good info there. Howard

[Pearson]

Re: Trim Stuck Full Nose up

Sounds like the jackscrew in the elevator might be stuck. I would open up the inspection plate at the base of the vert stabilizer and see if you can turn the pully by hand. If you can't, the jack screw is locked up. If you can turn the pully, it may be that you just ran the trim all the way one way to the stop and need to unscrew the jackscrew a little bit to break it loose. Hopefully a photo of the jackscrew will be attached to this post for your reference. Good luck!

[lfries]

Re: Trim Stuck Full Nose up

Happened to me once. Very tiring getting back to the airport. A little lube on the Jack Screw restored normal operation

[rcefird]

Re: Trim Stuck Full Nose up

Mine did the same thing not long after purchasing it a couple of years ago. Most likely the jackscrew as the others have already stated. Mine did not have any type of inspection/lubrication port and had not had any service since at least 2000 when it was recovered. We cut a hole in the fabric and sure enough the screw was stuck and encrusted with old dried grease. No problem to loosen and lube. If you do not have an inspection port at the jack screw, you need one to periodically lube the jack screw. You can look at the picture posted and get the relative measurements to locate the screw.
Randy

[Len Petterson]

Re: Trim Stuck Full Nose up

The O- sh-t factor goes high! and you have too use all you got in your arms to contol her.
1 Lube the trim in the little hole in the elevator spar tube under the fin. 3 4 drops off Light oil will do wounders here.
Do it on regular basis or after a rain if she ( the plane) is outside.
2 Chech your tension on the trim wire, I replaced the spring on the wire with one mush stronger.
3 Violin rosin on the wire will help, or if you have a rosin bag from bowling shake some over the wire in the front or in the rear.
4 If it happens again. Keep cool and climb to a safe alltitude back of on the power and try to move the trim again. Mine moved what way.
5 Fix it! No one need this problem!
I was told the trim does not move unless the elevator are in neutral possition.
Mine did onlly move in netutral possition before I changed the spring. Now it moves in any possition! the oilcan comes out every month.
Len

[jdoran]

Re: Trim Stuck Full Nose up

Check to see that the cable hasn't slipped on the pulley. Look behind you to see if the cable stop is dead up against one of the thinbles that it slides thru.

[jim34285]

Re: Trim Stuck Full Nose up

Many thanks to all who responded, the suggestions were great and we were able to free the jack screw up once we understood where the problem most likely was.
Thanks to all

Jim