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A Bell 47 helicopter, an early example of a powered rotorcraft. A rotary-wing aircraft, rotorwing aircraft or rotorcraft is a heavier-than-air aircraft with rotary wings that spin around a vertical mast to generate lift. The assembly of several rotor blades mounted on a single mast is referred to as a rotor.
Each type of helicopter has a specific airspeed at which a power-off glide is most efficient. The best airspeed is the one that combines the greatest glide range with the slowest rate of descent. The specific airspeed is different for each type of helicopter, yet certain factors (density altitude, wind) affect all configurations in the same manner.
The Bell 212 (also known as the Bell Two-Twelve) is a two-blade, twin-engine, medium helicopter that first flew in 1968. Originally manufactured by Bell Helicopter in Fort Worth, Texas, United States, production was moved to Mirabel, Quebec, Canada in 1988, along with all Bell commercial helicopter production after that plant opened in 1986.
3 July – A Pakistan Army Mil Mi-17 helicopter crashes in Khyber Pass, Pakistan, killing all 41 people on board. 8 August – A Eurocopter AS350 collides with a Piper PA-32R over the Hudson River between Hoboken, New Jersey and New York City, United States. The six occupants of the helicopter and the three occupants of the Piper aircraft all ...
The Bell 407 is a four-blade, single-engine, civil utility helicopter. A derivative of the Bell 206L-4 LongRanger, the 407 uses the four-blade, soft-in-plane design rotor with composite hub developed for the United States Army's OH-58D Kiowa Warrior instead of the two-blade, semi-rigid, teetering rotor of the 206L-4.
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more horizontally-spinning rotors. [8] By contrast the autogyro (or gyroplane) and gyrodyne have a free-spinning rotor for all or part of the flight envelope, relying on a separate thrust system to propel the craft forwards, so that the airflow sets the rotor ...
An autogyro (from Greek αὐτός and γύρος, "self-turning"), or gyroplane, is a class of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. While similar to a helicopter rotor in appearance, the autogyro's unpowered rotor disc must have air flowing upward across it to make it rotate.
The signs of VRS are a vibration in the main rotor system [8] followed by an increasing sink rate and possibly a decrease of cyclic authority. [9]In single rotor helicopters, the vortex ring state is traditionally corrected by slightly lowering the collective to regain cyclic authority and using the cyclic control to apply lateral motion, often pitching the nose down to establish forward flight.