blade flapping — The vertical movement of a helicopter rotor blade about a horizontal or flapping hinge, in which the blades tend to rise and descend with respect to the rotor hub as they rotate. Blade flapping tends to minimize asymmetrical lift by increasing… … Aviation dictionary
Retreating blade stall — is a hazardous flight condition in helicopters and other rotary wing aircraft, where the rotor blade rotating away from the direction of flight stalls. The stall is due to low relative airspeed and/or excessive angle of attack (or AOA).… … Wikipedia
helicopter — /hel i kop teuhr, hee li /, n. 1. any of a class of heavier than air craft that are lifted and sustained in the air horizontally by rotating wings or blades turning on vertical axes through power supplied by an engine. v.i. 2. to fly in a… … Universalium
Dissymmetry of lift — in rotorcraft aerodynamics refers to an uneven amount of lift on opposite sides of the rotor disc. It is a phenomenon that affects single rotor helicopters in lateral flight, whether the direction of flight be forwards, sideways or in reverse.… … Wikipedia
Helicopter noise reduction — is a topic of research into designing helicopters which can be operated more quietly, reducing the public relations problems with night flying or expanding an airport. In addition, it is useful for military applications in which stealth is… … Wikipedia
Helicopter — For other uses, see Helicopter (disambiguation). Helicopter An LAPD Bell 206 … Wikipedia
Sikorsky S-69 — Infobox Aircraft name= S 69/XH 59 caption= Sikorsky S 69/XH 59 with auxiliary turbojets type= Experimental helicopter manufacturer=Sikorsky Aircraft designer= first flight= July 26 1973 introduced= retired= status= primary user= NASA more users=… … Wikipedia
dissymmetry of rotor thrust — A condition in which one side of a rotor disc produces more thrust than the other. The speed of relative airflow over the advancing blade is higher than that of the retreating blade. The rotor thrust of the advancing blade also is higher than… … Aviation dictionary
Vertical axis wind turbine — Vertical axis wind turbines (VAWT) are a type of wind turbine where the main rotor shaft runs vertically. Among the advantages of this arrangement are that generators and gearboxes can be placed close to the ground, and that VAWT do not need to… … Wikipedia
asymmetric lift — A condition in which the rotor of a helicopter produces uneven lift in forward flight. When a helicopter is hovering, both the advancing and retreating blades produce the same amount of lift. However, in forward flight, the advancing blade is at… … Aviation dictionary
