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Levitation (on Earth or any planetoid) requires an upward force that cancels out the weight of the object, so that the object does not fall (accelerate downward) or rise (accelerate upward). For positional stability, any small displacement of the levitating object must result in a small change in force in the opposite direction.
Flight control system (helicopter) – A helicopter pilot manipulates the helicopter flight controls to achieve and maintain controlled aerodynamic flight. [72] Changes to the aircraft flight control system transmit mechanically to the rotor, producing aerodynamic effects on the rotor blades that make the helicopter move in a deliberate way.
When the helicopter rotor stalls, it does not do so symmetrically, because forward airspeed causes higher airspeed on the advancing blade than on the retreating blade. The retreating blade stalls first and its weight makes it descend as it moves aft, while the advancing blade raises as it goes forward.
In a spacecraft, the destination is usually an orbit, while for aircraft it is their landing location. A higher mass fraction represents less weight in a design. Another related measure is the payload fraction, which is the fraction of initial weight that is payload. It can be applied to a vehicle, a stage of a vehicle or to a rocket propulsion ...
For a helicopter on the ground, as the blades rotate, they describe a horizontal disc due to centrifugal force. However, as the helicopter generates lift, the blades are pulled upwards into a cone shape. [1] [2] [3] Coning results from the balancing of centrifugal and aerodynamic forces. [4] The coning angle depends on RPM, gross weight and g ...
The center of gravity is even more critical for helicopters than it is for fixed-wing aircraft (weight issues remain the same). As with fixed-wing aircraft, a helicopter may be properly loaded for takeoff, but near the end of a long flight when the fuel tanks are almost empty, the CG may have shifted enough for the helicopter to be out of ...
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
Aircraft flight mechanics are relevant to fixed wing (gliders, aeroplanes) and rotary wing (helicopters) aircraft.An aeroplane (airplane in US usage), is defined in ICAO Document 9110 as, "a power-driven heavier than air aircraft, deriving its lift chiefly from aerodynamic reactions on surface which remain fixed under given conditions of flight".