A gyrocopter, also known as an autogyro or gyroplane, is an aircraft that uses an unpowered rotor in free autorotation to develop lift, and an engine-powered propeller, similar to that of a conventional airplane, to provide thrust. Unlike a helicopter, the rotor of a gyrocopter is not engine-driven during flight, but is instead allowed to spin freely in the airflow.

Here are some key points about gyrocopters:

1. Lift: The main rotor blades of a gyrocopter spin due to aerodynamic forces (specifically autorotation) rather than engine power. As the aircraft moves forward, air flows upward through the rotor, causing it to spin and generate lift.

2. Propulsion: The forward motion is provided by an engine-driven propeller, which can be positioned at the front or rear of the aircraft.

3. Control: Pilots control gyrocopters through a combination of manipulating the pitch of the rotor blades, adjusting the aircraft's center of gravity, and using control surfaces like rudders and elevators, much like in fixed-wing aircraft.

4. Safety: Gyrocopters are inherently stable because of the gyroscopic forces generated by the spinning rotor. In the event of an engine failure, the rotor will continue to autorotate, allowing for a controlled descent and landing.

5. Uses: Gyrocopters are often used for recreational flying, agricultural applications, surveillance, and some other specialized tasks. They are more compact than helicopters and often cheaper to buy, maintain, and operate.

6. History: The gyrocopter was invented by the Spanish engineer Juan de la Cierva in the early 1920s, as a response to the frequent stall and spin accidents experienced by fixed-wing aircraft of the era.

While gyrocopters may look similar to helicopters, their operation and principles of flight are different. One of the main benefits of a gyrocopter is its safety during an engine-out scenario. Since the rotor is not powered, there's no risk of the rotor stopping abruptly if the engine fails, allowing the gyrocopter to glide and land safely.