Strange Harrier D7 crash

Hi everyone,

This is a crash that occurred while applying minor step inputs with the RC on the Roll angle of a Harrier D7. We were trying to tune the P gain of Roll angle and Roll angular velocity, namely parameters MC_ROLLRATE_P and MC_ROLL_P.

Prior to this crash the aircraft had done three consistent flights with default PX4 parameters (only battery configuration was changed and calibration performed) and two flights with 0.10<MC_ROLLRATE_P<0.25 and 5.0<MC_ROLL_P<8.0. The crash occurred with MC_ROLLRATE_P=0.20 and MC_ROLL_P=5.0.

Some additional information:

  • Pixhawk Cube 2.1 at Yaw270
  • Calibration and ESC calibration performed on the spot prior to flights
  • Minimum PWM input set to 1150.

We cannot figure out what caused the issue. Any ideas would be appreciated.

Log attached:

Thank you and regards,