We are flying a mission to photograph a gas pipeline in Thailand. Yesterday we had a serious problem with our mission.
All was going well, until we reached waypoint #50.
The airplane started to become extremely unstable, banking left and right and getting sometimes into a spiral downwards. On top of that, the camera stopped making pictures, although the logfile shows pictures are being triggered until waypoint 51.
The behavior became worse and when we almost reached home, we took over with FBWA. Within sight, we noticed the spiral down again and switched to QHOVER. The plane stabilized, but unfortunately, the airplane disappeared behind trees and we crashed.
Luckily we did not damage any third party properties, but the aircraft was damaged beyond repair.
The logfile is here:
I have been analyzing the logfile, but I cannot find the root cause of this problem. We noticed we had bad compass health, but looking at the EKF, we did not see anything. Also, everything went perfectly OK until waypoint 50
Please help, this looks like a serious problem to me.