Primary Flight Controls
What axis does the aileron pivot or produce movement around?
Longitudinal axis
Tendency of the aircraft to try to return to straight and level flight after it has been disturbed.
What environmental factor affects the speed of sound.
Temperature
What type of wing design can be more affected by adverse yaw?
A higher aspect ratio wing
How do spoilers help support roll/bank of the aircraft
They can aid the ailerons by spoiling the lift on the downward wing, disrupting airflow and reducing lift causing the aircraft to roll in that direction.
Wing dihedral can help increase what type a stability?
Lateral stability about the longitudinal axis
How does the speed react with temperature changes?
Speed of sound decreases with a decrease in temperature.
What type of wings are used if lateral stability is excessive and the aircraft is hard to maneuver?
Anhedral wings
What are the 3 primary flight controls and what movements do they perform for the aircraft?
Ailerons-Roll
Elevators-Pitch
Rudder-Yaw
Describe dynamic stability.
Rate of change in these forces over time after a disturbance
The aircrafts response to disturbances over time, its the rate of change in these forces, particularly the way it oscillates when returning to its original flight condition.
What is the ratio of the speed of the aircraft to the speed of sound called?
Explain the difference between a fixed horizontal stabilizer and stabilator?
Fixed horizontal stabilizer: Horizontal stabilizer is fixed with attached elevators
Stabilator: Not a horizontal stabilizer separate from an elevator, one solid surface that moves together
Explain 4 special primary flight controls.
Elevons: Works together as elevators and differentially as ailerons
Stabilator: No horizontal stabilizer, the whole surface moves like an elevator
Ruddervators: V-tail aircraft use ruddervators as both rudder and elevator
Canards: Does the job of a elevator or stabilator but located at the nose of the aircraft
Having the center of gravity forward of the center of pressure provides stability along what axis?
Provides stability about the lateral axis, providing good longitudinal stability.
Where on a wing does a shock wave initially form.
On the upper surface.
The vertical fin of an aircraft provides what type of stability to the aircraft?
Directional stability about the vertical axis
What is “Adverse Yaw”? Name 3 ways to minimize.
When the nose turns in the opposite direction of the intended banked turn. Differential aileron travel, Frise ailerons, Automatic rudder
How will an aircraft react after it has been disturbed from straight and level flight if it has a positive static stability and negative dynamic stability.
Ever-increasing oscillations about the original flight attitude, increasing over time with controllability being lost.
Explain how Supersonic airflow is different from Subsonic airflow
Supersonic airflow is “compressible.” The air speeds up to reach the speed of sound and compresses and shock waves are formed, therefore Bernoulli’s Principle does not apply to it.
Explain dutch roll and explain what can counteract it?
A combination yawing and rolling oscillation that affects many swept wing aircraft. Counteracted by a yaw damper system.