Jump to content

Recommended Posts

Posted

Hi, I'm having a problem with the elevator servo, or so I think. My problem is that the autopilot works well sometimes but not at other times. When it works badly, it makes the plane fly like a dolphin, it goes up and down and gets stronger and stronger. I have to disconnect it. The question is; has anyone else had the same problem? If not, what was the fault and who repairs these autopilots or the servos? 

Posted

It might not be the servo.  I'm not sure what CT type or AP you have, but if it's a TruTrak you can check the pitch axis settings and adjust the vertical activity, torque, static lag, and microactivity.   The manual specifically mention that if the airplane oscillates in pitch you might have lag in the static system which you can adjust out with the static lag setting.  I'd start there.

Here's the TruTrak manual for the common TT Digiflight series. If it's a different AP then look through the manual and it will probably have similar settings.

https://www.bendixking.com/content/dam/bendixking/en/documents/document-lists/downloads-and-manuals/DigiFlight-II-Series-Autopilots-Operating-Handbook.pdf

Posted

Yes, it is a tru trak, I checked the servo and it seems to be fine, today I went out flying, it worked perfectly for 10 minutes, I disconnected it and then every time I connected it I pulled the lever back and then forward, having to disconnect it immediately.

Posted

Check the shear screw on the pitch servo. If it is good, it is probably the head. Unfortunately I don't think there is anyone who repairs them. You might be able to find a used head, otherwise you will have to replace it with a new unit. The bad thing is they are not available in the rectangular form any more. This means a new panel to go along with the new head. There will also be some wiring involved.

Posted

Make sure you respond to its calls for trim.

If it shows vertical lines moving on the screen, you need to trim to remove them.

Too great of pressure and it will lose torque and then try to reapply resulting in porpoising.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...