I ask a question for a friend who had a crash.
Crash occurred in autotune when tuning Pitch axis. all the other axis are adjusted correctly. Just before crash the vehicle turned upside down and crash. Looking the log file it looks like GPSglitch on GPS2.
It would be grateful if someone could explain better what the cause of the crash…
Gps_auto_switch= Blend
For large copters (with props at least 13inch or 33cm diameter) set the Rate Roll and Pitch filters to 10hz (in Copter-3.3 these are RATE_RLL_FILT_HZ and RATE_PIT_FILT_HZ, in Copter-3.4 they are ATC_RAT_RLL_FILT, ATC_RAT_PIT_FILT)
Had the same happen when I left these at default and tried autotune.