[HELP] Pixhawk Cube & ArduPlane | Plane veered off course and crashed during landing

Everything was going very well, the plane was flying smoothly in AUTO mode. However, during the descent, a few waypoints before landing, it deviated significantly from its course and fell several meters away.

We have a Pixhawk Cube Orange and a dual Here3 GPS module. The aircraft also has a Lidar and a pitot tube.

The log of the flight is here. (After the main flight, nonsense data came, as the GPS data deviated excessively. You can reference the Throttle data to understand when it flew and crashed.)

Flight Log

The aileron is severely out of trim, with maximum left aileron used in a lot of the flight. The aircraft either has a severe left/right imbalance or the control surfaces are very badly trimmed. ArduPilot did it’s best to try to control the aircraft, but lost control at the end.
These were the control outputs:

the red line is aileron. A value of -4500 is full left aileron. You will notice that the aileron never went past 50% left, even when turning right.

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tridge, thank you very much for your reply. There is only one aileron channel on the plane, they are not separate as right and left. One servo is normally connected to this channel, while the other is reverse connected to this channel. Ailerons work against each other. Could this be the cause of the situation in the chart?

We looked at the plane and found slight mismatch in the ailerons.

In addition, what can we do to increase stability and especially to follow waypoints better and fly closer to waypoints, what are your recommendations?

I compared the data of this flight with another flight I took a week ago at the same place, which went well. I think the negative side is right aileron (or at least the plane is turning right on the negative side.)

This is the aileron graph of today’s flight:

Here is the graph of my previous stable flight at the same location:

Log of this, previous and normal flight:

Log File

I don’t know if I’m looking at the right thing and getting the right thing. But this difference is truly startling.

The question is, is it really in the aileron? If so, it’s really interesting

check if the servo has a stripped gear, or the cog is loose, or the servo not well seated. Try putting pressure on the surface while moving it

I checked the servo connections of the plane today. As a result of a fatal design error, the servos have become lockable.

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