What is the primary purpose of autorotation in helicopters?

The primary purpose of autorotation in helicopters is to allow a helicopter to land safely without engine power. This is a critical safety feature that enables pilots to manage situations where the engine fails or loses power. During autorotation, the helicopter's rotor system continues to generate lift due to the forward motion of the aircraft and the descent of the rotor blades. The pilot can control the descent and manage the landing by adjusting the pitch of the rotor blades, which allows for maintaining control during the approach and landing phase. This capability is vital for ensuring that the helicopter can reach the ground safely, even when the engine is not functioning, providing an essential emergency procedure for pilots.