Today I tested the 4.0rc1 version of the traditional helicopter firmware, focusing on its difference from the 4.0 dev. There are two distinct differences in flight. First, the brake action in the Loiter mode has finally returned to normal, because I set the parameter LOIT_ANG_MAX=45000. The default before this is 0, according to the wiki’s parameter definition, if set to 0, it should be called the total flight angle limit (uses ANGLE_MAX value), but obviously the flight control does not logically call the ANGLE_MAX parameter value, because the previous ANGLE_MAX The value I set is 45°, and LOIT_ANG_MAX is set to 0, but when the joystick is released, the aircraft does not have a timely reverse-lifting brake action. The second one, Yaw’s yaw operation feels a significant delay, and I have not modified the relevant parameters in 4.0 dev before, which I will carefully compare.Overall, the 4.0rc1 virgin test is smooth, thanks to the efforts of developers.