Really fun failure. Overheated?

ArduCopter Copter 3.3
1

Hey everyone,

Today I decided it was a good idea to fly my heli in the desert in 105 degree heat and ran into a problem, I was flying a heli but that isn’t really important for my issue so I posted in this forum because it gets more views. I will work on getting a log file up first thing tomorrow if necessary.

Upon landing the helicopter something went really wrong, it cut out connection to RC, and continued to output a PWM to the motor from Channel 8, so essentially I couldn’t stop the helicopter’s motor from running, and I was forced to sit and watch the helicopter run until the batteries died. We tried disarming the pixhawk via mission planner but it didn’t fix the problem, and just served to end our data logging. Basically my question is thus: is it possible for the pixhawk to overheat, and just maintain a latest pwm output to the motor channel, and cut out connection with the RC? Is this a deeper problem with my particular pixhawk and would it need to be replaced? Or should I be looking at potential ESC problems?

Any help is very much appreciated,

Sebastian

2

The log should easily show what the desired value for RC8 is.

I would start there.

Then if it is a high value I would look into the flight mode and condition. If this is a bug in the software it sounds like it could be very dangerous.

Please post the logs as it tells a lot more than wild guessing.

3

Dataflash log ends when we try to disarm the heli through mission planner.

No matter what it says the motor kept spinning. Looks to me like it got frozen with the outputs.

The interesting thing for me from the telem log is once we disarm it from missionplanner we can’t rearm it and we get the warning “arm: motor not spinning”. I have no idea what that means or how it could know that. This is a traditional helicopter with the latest firmware.