Autorotation doesn't involve the rotor rotating in reverse. It involves changing the pitch of the blades so that an upward airflow keeps them moving while they

Autorotation doesn't involve the rotor rotating in reverse. It involves changing the pitch of the blades so that an upward airflow keeps them moving while they generate some lift. It's like a wing in the sense that it resembles the operation of an autogyro, which has an unpowered rotary wing.