Stability Flashcards
When an object is disturbed and returns to its original path but in doing so it starts to oscillate at an increasing rate it is said to be statically —— and dynamically ——
Stable
Unstable
A dynamic stability function can exist only if there is —— stability.
Static
Most helicopters, stick held, are statically ——- and dynamically ——-. Stick free most helicopters are statically ——- and there( can, can not)be a dynamic function under those circumstances.
Stable
Unstable
Unstable
Cannot
Longitudinal stability is in the ——- plane around the (longitudinal, lateral, normal) axis. Lateral stability is in the ——- plane around the (longitudinal, lateral, normal) axis. Directional stability is in the ——- plane around the (longitudinal, lateral, normal).
Pitching
Lateral
Rolling
Longitudinal
Yawing
Normal
Stick held, when a gust of wind strikes a helicopter on the nose during a hover,dynamic (stability, instability) will cause it to oscillate forward and back at a (reducing, increasing) rate.
Instability
Increasing
The main function of a stabiliser is to dampen out (static, dynamic)oscillations. In rearward flight it has a (positive, negative) influence on longitudinal stability.
Dynamic
Negative
Synch elevators (can, cannot) pitch up/down, they respond to cyclic ( fore/aft, left, right) movements only.
Can
Fore/aft
Beyond a certain speed in forward flight, most helicopters are directionally statically —— and dynamicaly ——-.
Stable
Stable
Control power is a function of the effectiveness of ( collective, cyclic)to achieve changes in fuselage attitude. Generally the rigid rotor has (most, least) control power, the semi rigid rotor has (most, least)
Cyclic
Most
Least
Offset flapping hinges( do, do not) assist in keeping the fuselage parallel with the rotor disc and they allow a (wider, narrower) range of centre of gravity position.
Do
Wider
