Altitude issues in Loiter, high Nav pitch demand, abrupt crash in Fly by wire


I had a routine flight for an hour or so with my pixhawk in arduplane 3.5.2. The plane flew well for about fifty minutes or so in auto. After that, I switched to loiter a couple of times. Each time, the altitude dropped immediately on switching to loiter. I then decided to land and switched to FBWA. I started to approach for landing, when suddenly, after a turn, the plane plummetted nose down and crashed.

I was using a RFD900 for telemetry.

Some observations I’ve made -

  • The mission planner showed an altitude of 17m at the time of crash.

  • The Nav pitch was always high, about 40 degrees during the auto flight

I tried to attach the logs, but I couldnt, so I have put it in a drive link

Any help would be much appreciated. Thanks