Air Command Linear Trim Motor Mod

N962GT

Active Member
Joined
Oct 25, 2020
Messages
131
Location
orig Northville, Mich
Aircraft
YG4 Air Command Tandem
Total Flight Time
800 hrs
When flying particularly heavy passengers I run out of back stick trim to make the stick feel neutral. The solution was going to be to drop the attachment points down on the mast another inch, but then I'd lose the full forward (no back trim pressure) while taxiing and flying "dead stick" that I like.

Last weekend I lost the trim switch, and while troubleshooting the loss of power to the trim motor I took the trim mechanism apart. This turned out to be a good thing, as I realized my trim motor - which was used on Ford power windows a few decades ago - was only allowing 4" of a possible 5-3/16" of travel, limited by placement of the stop switch on a circuit board. This trim mech was popular on Air Command tandems back in the day, and I've seen several at meets on other gyros, so I'm sharing this mod here in case others might find it useful.

The red circle in the photos shows where the micro switch was located originally, and you can see where I've relocated it at the top of the circuit board. This mod increases travel 25%. I've relocated the linear motor down 1-1/4" lower on the mast, and retained the "dead stick" neutral trim I like so much for taxi and long, no-power landings.

IMG_4700.JPG
IMG_4699.JPG
IMG_4698.JPG
 
Top