View Full Version : TT trim sensing issue

12-08-2009, 06:28 PM
I have been having an issue with my TT Digitrak II VSGV and wondering if anybody else has the same experience.
I trim the plane for a given speed/altitude and engage the AP, then I see the AP wanting a bit of nose up trim. After timing it a bit.. It seems all happy but as soon as I disengage the AP, sure enough I am nose up. Is this some thing that can be adjusted? Why is it that when the airplane is perfectly trimed, the AP think that is not and wants a bit of nose up trim?
Thanks in advance
RV7A - IO360M1B

Rick S.
12-08-2009, 06:36 PM
You may want to check your servo torque settings, also TT has a great user forum on their website and great tech support, you may have one of their techs answering this question, on this forum, before you can call them, which I highly recommend. The auto trim function is one upgrade I should have taken advantage of but as I've said before, what else do I have to do but stay in communications with ATC, the "trim up/trim down" lady keeps me company!!

12-08-2009, 07:12 PM
I had the same issue with my AP100 and I talked to Jim at Sun n' Fun last spring. He knew exactly what the problem was and told me to send the pitch servo to them whenever possible and they would adjust it. I sent it in during my condition inspection last month and they turned it around in a day and it works great now. No charge. Typical great TT service!! I've flown behind many different autopilots over the years, and this is better than any of them.

12-09-2009, 07:22 AM

Your elevator servo will need to come back to us for recalibration of the trim sensor. Give me a call or send me a PM when you want to send it back and I'll get you an RMA number. Thanks!