AP cutting out

[7965A]

I just did a flight from Reno-Denver and return and had issues with the AP.  I have D100, D120 with pitch and roll servos, running 5.4 and no HS34 or AP76.  Periodically on both flights,  the AP would just disengage itself, in either pitch or roll (not necessarily both - sometimes one, sometimes the other, sometimes both) for no obvious reason.  Reboot did not solve the problem.  It occurred a lot (maybe 30-40 times in a two-hour flight).  Time between occurrences was highly erratic (little as one minute, as long as 10 minutes).  Air was smooth.  The only thing I can think of is a short somewhere.  Any suggestions for troubleshooting would be welcomed.

greg
RV-9A

 

[dynonsupport]

Did you see any error messages that accompanied the disengage? What does the AP status for that axis say after the disengage? OFF or ERR?

 

[7965A]

No error messages that I saw. The AP status in the menu bar simply said OFF. I kept the menu bar open much of the time so that I could re-engage the AP as necessary. When the roll AP went down, the status would go to HEADING (I normally run in NAV mode). I honestly don't remember whether the status (where the clock or timer normally sits) was OFF or ERR. I believe it was just OFF (would think I should have remembered that having seen it a bunch of times). I expect to be in the air again in the next couple days so will check on this and report back.

thanks,
greg

 

[DBRV10]

Check your AP disconnect wiring and switches for grounding. If you have the aural warnings setup you would have heard a disconnect, but if not you may not be aware.

 

[7965A]

Did a test flight today to check for error messages, but nothing happened (i.e., AP worked fine). Will try again (longer flight) maybe this weekend.

greg

 

[7965A]

Another test flight today. 20 minutes at 8500 ft, AP worked fine. Climbed to 17500, another 25 minutes and no problems. So I don't know what happened for those two days to Denver and back. The only difference is that the OAT was a bit lower on the long trip (~14-15 F) vs. today (~20 F).

Guess I'll just keep flying and see if it happens again.

greg

 

[7965A]

Closing out this thread. I have flown a number of times lately, did tests at altitude etc. and have seen no problems since those two flights to Denver and back. No idea what happened (the flights were 5 days apart) but everything seems to be working now.

Cheers,
greg