Okay: to clarify, when de-activating the main props, first deactivate AG1, so the smaller prop's throttle will be set to 100. Then, put throttle down. When landing, just activate, and then deactivate back again for the smaller props. That way, everything will be to 0, and then power up again to control only the heli rotors.

I am free to answer questions, as the video can be confusing since there is no commentary.