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Collective angle of attack for the rotor main blades via the swashplate: Increase/decrease pitch angle of all main rotor blades equally, causing the aircraft to ascend/descend Increase/decrease torque. In some helicopters the throttle control(s) is a part of the collective stick. Rotor speed is kept basically constant throughout the flight.
In helicopters, pitch control changes the angle of incidence of the rotor blades, which in turn affects the blades' angle of attack. Main rotor pitch is controlled by both collective and cyclic, whereas tail rotor pitch is altered using pedals.
As the angle of attack increases further, the upper surface flow becomes more fully separated and the lift coefficient reduces further. [7] Above this critical angle of attack, the aircraft is said to be in a stall. A fixed-wing aircraft by definition is stalled at or above the critical angle of attack rather than at or below a particular airspeed.
Retreating blade stall is a hazardous flight condition in helicopters and other rotary wing aircraft, where the retreating rotor blade has a lower relative blade speed, combined with an increased angle of attack, causing a stall and loss of lift. Retreating blade stall is the primary limiting factor of a helicopter's never exceed speed, V NE. [1]
Today, on most modern aircraft the swashplate is above the transmission and the pushrods are visible outside the fuselage, but a few early designs, notably light helicopters built by Enstrom Helicopter, placed it underneath the transmission and enclosed the rotating pushrods inside the mainshaft. This reduces rotor hub drag since there are no ...
angle of attack α: angle between the x w,y w-plane and the aircraft longitudinal axis and, among other things, is an important variable in determining the magnitude of the force of lift; When performing the rotations described earlier to obtain the body frame from the Earth frame, there is this analogy between angles: β, ψ (sideslip vs yaw)
[1] [2] Unlike fixed-wing aircraft, of which the stall occurs at relatively low flight speed, the dynamic stall on a helicopter rotor emerges at high airspeeds or/and during manoeuvres with high load factors of helicopters, when the angle of attack(AOA) of blade elements varies intensively due to time-dependent blade flapping, cyclic pitch and ...
P‑factor, also known as asymmetric blade effect and asymmetric disc effect, is an aerodynamic phenomenon experienced by a moving propeller, [1] wherein the propeller's center of thrust moves off-center when the aircraft is at a high angle of attack.