What is helicopter throttle?
Helicopter rotors are designed to operate at a specific rotational speed. The throttle controls the power of the engine, which is connected to the rotor by a transmission. The throttle setting must maintain enough engine power to keep the rotor speed within the limits where the rotor produces enough lift for flight.
What is helicopter ground resonance?
ground resonance. A resonance that manifests itself as a violent rocking of the helicopter when it is on the ground. This phenomenon is most evident when the helicopter is on hard surfaces that do not absorb vibration. It is caused by the resonance between the skid and the rotor system.
How do helicopters glide?
A smooth landing with no power. Actually, helicopters have a built-in mechanical control called the collective pitch lever that allows them to descend slowly and land even if the engine dies. This maneuver is called autorotation.
How do helicopters fly forward?
The rotor blades are pitched lower in the front of the rotor assembly than behind it. This increases the angle of attack — and creates lift — at the back of the helicopter. The unbalanced lift causes the helicopter to tip forward and move in that direction.
Why do helicopters get ground resonance?
Ground resonance happens in helicopters with lead-lag hinges. It occurs only on the ground. It starts when the blades “bunch up” on one side of the rotor disc where they generate an unbalanced centrifical force that gets in phase with the natural frequency of the aircraft rocking on it’s landing gear.
Why do helicopters shake?
A helicopter main rotor is capable of producing vibrations in both the vertical and lateral planes. A vertical vibration is a result of unequal lift produced by the main rotor blades. This vibration is a result of the airframe rolling with the mass effect caused by the unequal vertical lift component.
How does autorotation apply to a spin?
For fixed-wing aircraft, autorotation is the tendency of an aircraft in or near a stall to roll spontaneously to the right or left, leading to a spin (a state of continuous autorotation).