rotorcraft

Rotorcraft are aircraft in which lift is produced primarily by rotating wings or rotors that spin around a mast. The category includes helicopters, autogyros, tiltrotors, gyrodyne configurations, and other rotor-based platforms. Rotorcraft are capable of vertical takeoff and landing and can hover or operate from confined spaces, advantages that distinguish them from fixed-wing aircraft.

Helicopters generate lift and propulsion with a powered main rotor, while cyclic and collective pitch control adjust attitude and thrust. A tail rotor, or other anti-torque device, provides yaw control. Modern rotorcraft may use piston or turbine engines and complex gear reductions to deliver power to the rotor. Advanced rotor heads and variable-speed designs enable efficient flight across multiple regimes.

Autogyros use an unpowered rotor that autorotates in the airstream, with forward thrust provided by a separate propulsion system such as a propeller. Lift results from the rotor’s autorotation rather than engine power, so forward speed is required to sustain flight. Autogyros are generally simple and economical but cannot hover like helicopters.

Early rotorcraft work dates to the early 20th century, with notable efforts by Paul Cornu and others; Juan de la Cierva developed the autogyro in the 1920s. The first practical helicopter is credited to Igor Sikorsky, whose VS-300 demonstrated controllable vertical flight in the 1930s. Postwar turbine-powered designs expanded capacity and reliability.

Today rotorcraft are employed in transportation, emergency medical services, search and rescue, firefighting, law enforcement, and military reconnaissance. They excel in operations in confined areas and offshore environments but face challenges including safety, maintenance, weather sensitivity, noise, and cost. Developments such as tiltrotors and advanced rotor systems seek greater speed, efficiency, and payload.