Copter ascended while in "Land" mode (need help finding a cause)


This is my first post here. I am building a copter with S500 frame and Arducopter 3.5.5. My copter chrashed in the second flight. I started in “stabilize” mode and after noting some drifting decided to switch to “Land” mode. Instead of landing the copter started gaining altitude. I switched back to “stablize”, but (mainly because of a pilot error) crashed the copter.

Because I salvaged the most of the copter and going to fly again mostly with the same settings, I am trying to find the cause why the copter started climbing to prevent it in the future. My log file is here:

I am also concerned about “Yaw” values in the log. It looks like while ascending, the copter was also rotating uncontrollable. Could the reason for that be a failure of ESC or a motor?

Another question, which is related to this one. Presuming I have a log file and code of ardupilot, is it possible to debug ardupilot code by supplying a log file as a kind of a stub?

PS: Anyway I learned a lot from this flight.

The copter at high throttle has a lot of vibrations and also several Ekf errors, this could explain altitude and yaw errors.

Your battery is bad since it went to 11,4 volts while at 60A for a 4S it means death.

As lucamax suggested: the climb was due to insane vibrations, you need to “debug” your build long before mentioning any “code”.