Quad tilting left after loiter, rtl trouble also

Hi, I’m quite newbie with Quadcopters and APM.

I was about to try waypoint flying today, but little trouble with loiter and RTL postponed that.

When I was hovering quite nicely maybe 5-10m from home point and switched to RTL, Quad began to gain altitude (that was ok, 40m rtl alt…) but it also began to fly left from me and seemed like tried to fly away, so I switched quickly back to Stab and took control. Similar “out of control” behavior on couple other attemps also.

When switched to loiter, again began slowly fly to left and increased speed all the way. Loiter has worked fine before this. Althold was ok and flied nicely in stabilize also.

GPS had good reception and was locked before arming.

I’m wondering what was going on? Why GPS modes caused weird behavior?

Log attached. I have also on board video if that’s needed…

Yes I know, flew little too long, voltage went too low at the end.

I had trouble with gps earlier also, crashed the thing because of that, luckily not too bad damage and also waypoint flying went crazy after three waypoints. These was probably caused by loosing gps signal for a moment, maybe related to gps boards backup battery disconnecting in the middle of the flight.

I have
APM 2.6 +gps&compass. Firmware 3.1.1rc2
X650F frame
Propdrive 28-30s 800kv motors
Hobbyking 30a blue series escs, with Simonk firmware
Turnigy 9X

Is your GPS/Compass in the correct orientation? And do you have the compass parameter set to 180 degree rotation?

Just looked at your log, and the AHRS_ORIENTATION is not set correctly. Use MP or APM Planner 2.0 to configure your setup correctly.

Hi, rotation is correct, at least compass values makes sense with my settings. If I setted it to suggested rotation 180, it seemed to be just opposite. I don’t have original 3dr version, it’s from ebay.

The 3.3v regulator on my apm board has blown, I guess that could cause weird behavior. Ordered new regulator…

I still don’t understand what happened that day with the quad, couple flights after that and it has worked ok.