Stability Flashcards
Stability
Is the natural quality of an aircraft to correct for conditions that may disturb its equilibrium and return to or continue on the original flight path.
– Describes the initial response and subsequent behavior of an aircraft when it is disturbed from its trimmed condition by atmospheric effects, such as wind gusts or thermals.
Two types of stability
Initial response (Static Stability)
Subsequent behavior (Dynamic Stability)
Initial Response (Static Stability)
It refers to the aircraft’s initial response when disturbed from a given AOA, slip, or bank.
Subsequent behavior (dynamic Stability)
– Refers to the aircraft response over time when disturbed from a given AOA, slip, or bank.
Initial Response (Static Stability types)
Positive static stability
Neutral static stability
Negative static stability
Subsequent behavior (Dynamic stability types)
Damped oscillation - Dynamically stable
Undamped oscillation - dynamically neutral
Divergent oscillation - dynamically unstable
Directional stability
– Is the natural ability of an airplane to recover from a disturbance in the yawing plane.
– Stability around the vertical axis
Directional stability passive correction
Vertical Stabilizer
Directional stability active correction
rudder
Lateral Stability
– Is the natural ability of the airplane to recover from a disturbance in rolling without pilot input
– Stability around the longitudinal axis
Lateral Stability passive correction
High wing anhedral wings, Low wing Dihedral wings
Lateral Stability active correction
Ailerons
Longitudinal Stability
– Is the natural ability of the airplane to recover from disturbance in pitching without pilot input
– Stability around the lateral axis
Longitudinal stability passive correction
Horizontal stabilizers
Longitudinal stability active correction
elevators
