A/C Stability

Question 1

What is static stability?

Answer 1

The initial tendency or direction of movement of an aircraft back toward equilibrium after a disturbance.

Static stability is crucial for an aircraft’s ability to return to its original flight path.

Question 2

What is positive static stability?

Answer 2

The aircraft initially tends to return to its original state of equilibrium after being disturbed.

This type of stability is desirable for safe flight.

Question 3

What is neutral static stability?

Answer 3

The aircraft initially remains in the new condition after its equilibrium has been disturbed (neither returns nor diverges).

This can lead to a stable flight path if managed correctly.

Question 4

What is negative static stability?

Answer 4

The aircraft initially continues away from its original state of equilibrium after being disturbed.

This can lead to uncontrollable flight conditions.

Question 5

What is dynamic stability?

Answer 5

The tendency over time of the aircraft’s motion after a disturbance from its trimmed condition.

Dynamic stability is essential for long-term control of the aircraft.

Question 6

What is positive dynamic stability?

Answer 6

The oscillations decrease in amplitude over time and the aircraft returns toward equilibrium.

This indicates a well-designed aircraft that can recover from disturbances.

Question 7

What is neutral dynamic stability?

Answer 7

The oscillations neither grow nor decay; amplitude stays constant over time.

This can lead to a steady but potentially undesirable flight condition.

Question 8

What is negative dynamic stability?

Answer 8

The oscillations increase in amplitude over time, becoming more divergent.

This can result in loss of control and is highly undesirable.

Question 9

How do static and dynamic stability differ?

Answer 9

Static stability addresses the immediate post-disturbance tendency; dynamic stability describes the behavior over time (whether oscillations dampen, persist, or diverge).

Understanding both types of stability is crucial for aircraft design and operation.

Question 10

Can an aircraft be statically stable but dynamically unstable?

Answer 10

Yes. It can initially move toward equilibrium (positive static) yet have oscillations that grow over time (negative dynamic).

This scenario highlights the complexity of stability in aircraft.

Question 11

What real-world example illustrates neutral dynamic stability?

Answer 11

A worn automobile shock absorber: oscillations continue at constant amplitude without damping.

This example helps visualize neutral dynamic stability in everyday terms.

Question 12

What cockpit cue suggests positive dynamic stability after a pitch disturbance?

Answer 12

Successively smaller pitch oscillations that settle back to the trimmed attitude.

This cue indicates that the aircraft is regaining control after a disturbance.