CRASH_ potential Thrust Loss

Hello all,
I am building a quadcopter and It has been flying fine. Today I was doing a long range flight test and everything was fine until when I started to return then all of the sudden the copter started wabling then potential thrust lost then it crashed.
I dont understand the main cause. Can someone help diagnose this with the below logs?

-My motors and ESC are U8LITE-X, the KV190+ALPHA 60A LV+MF2815 30mm 1cw R, 1CCW R, 1CW G, 1CCW G

  • I am running Cube orange

Seems to be Motor/ESC1 losing thrust and is eventually commanded to maximum. Without it working the other motors/ESCs struggle to maintain flight.
I dont see an obvious cause, like huge current spike indicating an electrical fault. My personal opinion is use different ESCs or this will happen again.

HI Shawn, thanks for your reply. how did you tell it was ESC1? Would appreciate guidance to see which motors esc was faulty.

This can be told from the RCOUT. As you can see RCOU.C1 went maximum, this is a sign of ESC1/motor1 not getting enough thrust output as it should be. Thus Ardupilot tried to raise the output to regain lost thrust.

Thanks Alvin for the explanation. We are trying to understand why that happened, may be the pilot was a bit aggressive in the maneuvers?


As there was no significant voltage drop or high current consumption during RCOU.C1 went maximum, it seems there was no short circuit.

It may be mechanical failure or cable/connector disconnected / etc.

Maneuvers were not too aggressive before problem appear. At least achieved attitude is following desired attitude quite well.