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A typical helicopter has three flight control inputs: the cyclic stick, the collective lever, and the anti-torque pedals. [2] Depending on the complexity of the helicopter, the cyclic and collective may be linked together by a mixing unit , a mechanical or hydraulic device that combines the inputs from both and then sends along the "mixed ...
The critical rollover angle is 5°-8°. Once exceeded, main rotor thrust continues the roll, and recovery via cyclic control is impossible. [1] A helicopter is susceptible to a rolling tendency, called dynamic rollover, when close to the ground, especially when taking off or landing. For dynamic rollover to occur, some factor has to first cause ...
In aeronautics, a swashplate is a mechanical device that translates input via the helicopter flight controls into motion of the main rotor blades. Because the main rotor blades are spinning, the swashplate is used to transmit three of the pilot's commands from the non-rotating fuselage to the rotating rotor hub and mainblades.
These two effects, combined with any aft cyclic by the pilot attempting to keep the aircraft level, can cause the rotor blades to blow back and contact the tail boom, in some cases severing it. The tail rotor is geared to the main rotor, so in many helicopters the loss of main rotor RPM also causes a significant loss of tail rotor thrust and a ...
Cyclic/collective pitch mixing (CCPM) is a control concept employed in collective pitch radio-controlled helicopters. [1] CCPM reduces mechanical complexity and increases precision of control of the helicopter rotor's swashplate. Unlike conventional systems in which a single actuator is responsible for a single axis, CCPM mechanisms allow ...
A helicopter's main rotor hub. The vertical rods are at the end of the control chain that starts with the pilot controls. Helicopter flight controls are connected to the main and tail rotors, and include a cyclic stick, broadly to control forward-aft and left-right movements, a collective lever, broadly to control vertical movements, and anti-torque pedals, to control left and right yaw.
The cyclic control was found to be difficult to perfect, and led to Sikorsky locking the cyclic and adding two smaller vertical-axis lifting rotors to either side aft of the tailboom. [7] By varying pitch of these rotors simultaneously, fore and aft control was provided. Roll control was provided by differential pitching of the blades.
A Sea King helicopter landing on HMCS Assiniboine (DDH 234); the beartrap is the small rectangle on the flight deck. Recover assist landing of a SH-60B helicopter with a RAST system. A helicopter hauldown and rapid securing device (HHRSD) or beartrap enables helicopters to land on and depart from smaller ships in a wide range of weather ...