Hexacopter crash after EKF Check 2


so far, we never had any problems with the pixhawk. This new hexacopter flew so far great, without any problems.

Today we flew like always and after 20-30 seconds I saw that the GPS signal was gone and the copter drifted away. Later in the logfile I saw that the EKF Check2 and EKF 1 Failsafe, also that the magfield was to high.

The question is, what did I do wrong? I know I should have set it to altitude hold mode, after I saw the GPS signal was gone, but all happend so fast.

Maybe I´m missing something, if someone would check my log, I would really appriciate this.

22.BIN (1.1 MB)

I hope there wasn’t too much damage - it looks like the copter was not moving fast when it crashed.

The GPS signal goes very suddenly from 17 satellites to 0. I suggest you check the wires / connectors from Pixhawk to GPS first.

After an EKF failsafe, APM Copter always starts to land automatically, but without GPS it will drift away so you should control pitch / roll to stop it crashing.

You can also switch to Stabilise / Alt Hold during an EKF failsafe to fly the copter home manually.

The compass offsets are very high. I suggest you also move your GPS / compass further from wires and batteries and run new Live Calibration followed by compass MOT calibration.