Stability Flashcards
What are the three types of stability?
Positive - always returns to its original position following a disturbance
Negative - The slightest displacement will just get worse
Neutral - when it is displaced it will just stay in the new position
What is Static Stability?
The initial tendency of an aircraft to return to its original position after a displacement.
What is Dynamic Stability?
The overall tendency of the aircraft to return to its original position following a series of oscillations
Around which axis is longitudinal stability, lateral stability, and directional stability?
Longitudinal/Pitch Stability is around the lateral axis
Lateral Stability is around the longitudinal axis
Directional Stability is around the normal axis.
What affects your longitudinal/pitch stability?
The size and position of the horizontal stabilizer
The center of gravity (a nose heavy AC will be more stable)
What give a greater lateral/roll stability?
Dihedral (wings bent slightly upwards)
Sweepback (wings angled back)
Keel Effect (fuselage acts are a pendulum)
Proper distribution of weight
How is greater stability around the normal axis (Yaw Stability) achieved?
Tail surfaces, fin, rudder
Keel effect (pendulum)
Sweepback (wings angled back)
What is sweepback and how does it affect yaw stability?
What is inherent stability?
An aircraft that is inherently stable is one that is naturally stable due to the features incorporated into its design
EX:
Training AC are designed to be nice and stable
Aerobatic airplanes (and others) are often designed with neutral or negative stability
