Hello Ardupilot community. These years have been very successful, as I have encountered very few drone-related incidents thanks to the increased reliability of the flight controllers, better tuning, and sensors.
This time, however, something went wrong during a mission. The vehicle is a quad copter drone, using a carbon frame and relatively large propellers (28"). This vehicle had done recently hundreds of missions related to magnetometry (flying relatively close to the ground) without issues, until a recent mission where it suffered a hard landing and lost some landing gear legs.
After repairing the landing gear, during a new sequence of missions, the rotorcraft failed in the air while completing a line where there is sloping:
The craft was following a DEM from the region and suffered a sudden power loss with loss of attitude and a crash:
Interestingly, there is a loss of current leading to the failure and subsequent fall, which can be seen at the moment where attitude no longer can be sustained:
At that moment, the current reaches a low of 4.5A, which coincides with the inability of the copter to maintain attitude. Also, the drone starts spinning, suggesting a possible torque imbalance, also apparent in the way the controller responds to the disruption.
The interesting aspect of this motor failure with respect to the other ones we have had, is that power loss preceding the failure, as other motor losses did not affect the current flow as much as this one did.
The following is the link to the logs of the flight:
https://drive.google.com/drive/folders/1vFTTSMT5MFziPMbpQ9GlegwivYcB-vt_?usp=sharing
Thank you for your time