Stability

Question 1

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——-

Answer 1

Stable
Unstable

Question 2

A dynamic stability function can exist only if there is ——- stability

Answer 2

Static

Question 3

Most helicopters, stick held, are statically——- and dynamically——. Stick free, most helicopters are statically ——- and there (can, cannot) be a dynamic function under those circumstances.

Answer 3

Stable
Un stable
Un stable
Cannot

Question 4

Longitudinal stability is in the —— plane around the (longitudinal, lateral, normal) axis. Directional stability is in the —— plane around the (longitudinal, lateral, normal) axis.

Answer 4

Pitching
Lateral
Rolling
Longitudinal
Yawing
Normal

Question 5

Stick held, when a gust of wind strikes a helicopter on the nose during the hover, dynamic (stability, instability) will cause it to oscillate forward and back at a (reducing, increasing) rate.

Answer 5

Instability
Increasing

Question 6

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.

Answer 6

Dynamic
Negative

Question 7

Synch elevators (can, cannot) pitch up and down, they respond to cyclic (fore-aft, left-right) movements only.

Answer 7

Can
Fore-aft

Question 8

Beyond a certain speed in forward flight, most helicopters are directionally statically—— and dynamically ——.

Answer 8

Stable
Stable

Question 9

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).

Answer 9

Most
Least

Question 10

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 positions.

Answer 10

Do
Wider