Bad compass health

When I play back my last logfile I see sometimes Bad compass healt. What can cause this? In apm copter there is a compassmot but I didn’t see this feature in the apm plane.
Please help.

This is the logfile:
[attachment=0]2013-11-26_14-18-30.tlog[/attachment]

We get it as well, either there is an undocumented issue with the compasses or the new checks are too stringent and it’s a false alarm.

I’ve checked the sat count and hdop when the messages pop up and both seem fine so until we can get some confirmation from the developers we can’t do much about it.

I encounter the same message with a newly purchased UBlox unit. It is in a great position and I have checked for stray magnetic disturbance using a regular compass, which never deflects. Is this an issue caused by not enough sats? It is entirely possible, from my end, because I mostly see this during bench tests inside.

posted from the DIYdrones site if this helps anyone… It may be my problem here in this instance.

“The bad compass health is something that MP has recently started reporting. It is caused by APM:Plane detecting a inconsistency between your compass and your GPS heading.
For the 2.75 release I changed the code that detects the GPS/compass inconsistency to only trigger if they are inconsistent for more than 2 seconds. So if you update to 2.75 you should find the messages are much rarer.
I don’t know why MP would display “NO RC Receiver” as we don’t set that bit in 2.74 or 2.75. Can you post a tlog of that?
Cheers, Tridge”