i use h743mcu and no compasswith dolphin fpv ，when i changed the fmod to rtl then plane gose to roll around and keep upside down.
here is log https://drive.google.com/file/d/1-0s1KS_KbqbYODuca6jyP_U7i63WrRC2/view?usp=drivesdk
Welcome to the forum.
Please unlock your google drive so that the logfile can be downloaded.
Rolf
thx for reply i has been unlocked！
The high speed of your aeroplane stands out in contrast to your speed settings in Arduplane. You had very little wind, so for the sake of simplicity I’ll use GPS speed as approximation for the airspeed.
At the end of the RTL your aircraft reaches over 40 m/s in climb without any problems!
However, your speed parameters are much lower:
AIRSPEED_MIN 9 m/s
AIRSPEED_CRUISE 12 m/s
SCALING_SPEED 15 m/s
AIRSPEED_MAX 22 m/s
TRIM_THROTTLE 45%
In cruise mode you can see that with 45% throttle the aircraft reaches more than 20 m/s.
I suspect that due to the inadequate speed parameters, the auto-throttle control gave far too much throttle at the moment you switched to RTL, because suddenly a climb to an altitude of 150 metres (RTL_ALTITUDE) in a tight turn was to be controlled. When recovering from the turn, a control reversal of the elevons probably occurred at 40 metres per second. If it is a foam plane, I think this is very likely.
However, I am not 100% sure.
I would check whether the aircraft is suitable for 40 m/s
and adjust the speed parameters in any case and then fly another autotune.