This is my first time asking question in this forum, I have a problem with my quadplane, its a conventional airframe with 4 brushless motors on arms like many others and a brushless motor in the nose. I was tune it manually and it was very good in stability during my tests. in the first flight everything was okay but some oscillations in roll and pitch in the moment of transition to the quad mode ( QLOITER mode ). in the second flight I figured out the pitch angle is very high during the back transition, so I reduced the Q_LOIT_ANGLE_MAX to 10 deg from default 30 deg and also changed the Q_ANGLE_MAX from 3000 to 1000. I hoped to have better back transition but in the end of my third flight I was in the FBWA flight mode and in the speed of 15m/s I switched to the QLOITER mode, the plane was act very hard in the pitch, the nose up was very strange and the plane started rotating in the yaw axes. and finally it caused a crash. The wind was calm and heading was in the direction of the wind when I switched to the QLOITER mode. please have a check on my parameters file and please let me know if there is any mistakes in my settings.
here is the parameters file : https://filebin.net/6cqs8b31rpcorjq9/myParameters.param