Been using aircraft in question with AP3.9.1 since it was released (20-30 flight hours) without any issues.
Updated to 3.9.2 a week and a half ago nothing else changed. First flight on AP3.9.2 resulted in crash while in RTL mode.
Took off in FBWA, got up to speed, engaged RTL, did 1 successful turn, on the second it stalled, rolled 180, recovered, started 3rd turn, but stalled again, this time it was about 1-2meters above the ground so crashed. After going through the log, I noticed that airspeed logged 2-4m/s which is waay low, as stall speed is 8m/s and I clearly remember plane was flying and climbing. I checked i2c airspeed sensor and found that VCC wire was broken under insulation and making sporadic connection. Fixed the issue, check other wires.
LOG#1
Today, still at 3.9.2. All pre-flight checked out good. Took off in FBWA, got up to speed 20m/s+ verified through OSD, engaged RTL. This time plane rolled 180 at the first turn attempt but recovered, than attempted 2nd turn and recovered again. At this point I’ve switched to FBWA, but was too far to see orientation clearly, so while getting googles on lost airspeed and stalled again, At that point I’ve killed throttle and put the plane into a field as it was getting too close to a public road.
LOG#2
I think that maybe some parameters changed after the update process, or maybe there is some other issue, but RTL at 3.9.2 clearly overshoots roll angle, while at 3.9.1 it was a great flier.
Any input is much appreciated!
