Helicopter

A rotorcraft whose powered blades provide lift and control, enabling vertical takeoff, hovering, and flight in multiple directions.

Main rotor: A helicopter’s powered rotating blade assembly, which produces most of its lift and control forces. Changing blade pitch lets the main rotor vary lift and tilt thrust to steer.
Rotor aerodynamics: The study of airflow and forces around rotating blades. It explains how blade shape, speed, and pitch generate helicopter lift.
Search and rescue: The locating and recovery of people in danger or distress. Hovering and landing in confined areas make helicopters useful for rescues.
Fixed-wing aircraft: An aircraft whose wings remain stationary and generate lift through forward motion. Unlike a helicopter, it generally needs a runway and cannot hover.
Igor Sikorsky: An aviation engineer whose VS-300 helicopter helped establish the modern single-main-rotor configuration. His design shaped the layout used by many later helicopters.
Swashplate: A mechanical assembly that transfers stationary control inputs to rotating rotor blades. It changes blade pitch collectively or cyclically as the rotor turns.
Lift (force): The aerodynamic force perpendicular to the relative airflow over a surface. A helicopter’s rotor produces the upward force needed to support its weight.
Air ambulance: An aircraft equipped to transport patients and provide medical care in flight. Helicopters can reach remote patients and rapidly transport them to hospitals.
Autogyro: A rotorcraft whose unpowered rotor turns in airflow while an engine drives a separate propeller. Its rotor autorotates in normal flight rather than receiving engine power directly.
Paul Cornu: A French bicycle maker and aviation pioneer who built an early piloted helicopter. His 1907 flight is commonly cited among the first brief free helicopter flights.

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