????? ??? ???? ???? ???? ?? ???????? ???? ??? ???? ??? ???? ???? ???? ???? ??????? ???? ??????? ???? ?????? ?????.Some helicopters have more than one rotor and a few have rotors turned by fuel jets at the tips. Some Possess a tail rotor to counteract the rotation of the main rotor, also to assist directional Management.For the duration of this proc