In a helicopter, the rotor is powered by an engine-driven transmission system. The transmission system usually consists of a series of gears and shafts that transfer power from the engine to the rotor head. The rotor head is a complex mechanical assembly that connects the rotor blades to the transmission system and allows them to rotate freely. The engine provides the power to turn the rotor, and the transmission system transfers this power to the rotor head. The rotor head then uses this power to turn the rotor blades.
In an autogyro, the rotor is not powered by an engine. Instead, it is turned by the force of the air flowing over it. The autogyro's rotor is similar to a windmill, and it is tilted at an angle to the direction of flight. As the autogyro moves forward, the air flowing over the rotor creates lift, which causes the rotor to turn. The faster the autogyro flies, the faster the rotor turns. The rotor in an autogyro provides lift, while the engine-driven propeller provides thrust.
