Flight controls Flashcards
An ailerons that has greater up travel than down travel are what type of ailerons?
Differential ailerons
If an aircraft doesn’t have a tail-mounted elevator or horizontal stabilizer, what might the aircraft have instead that does the same job?
Canards
Why does a canard reach the stall point prior to the wings?
Because they are mounted at a higher angle of incidence, this allows the nose to drop, lowering the pitch angle before the wing can reach its stall angle
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?
Ailerons (roll)
Elevators (pitch)
Rudder (yaw)
What is adverse yaw?
When the nose turns in the opposite direction of the intended banked turn
Name 3 ways to minimize adverse yaw
Differential aileron travel
Frise aileron
Automatic rudder
Explain how the elevator works in flight (control, direction of travel, A/C reaction)
Elevator attached to horizontal stabilizer, stabilizer/elevator forms airfoil.
Control wheel FWD, elevators down, nose pitches down (tail up)
Define stabilator
Special primary flight control, where the whole surface moves like an elevator, typically requires a secondary flight control attached (anit-balance tab) from increased required force to move the stabilator
What is static stability?
Tendency of the aircraft to try to return to straight and level flight
What is dynamic stability?
Is the “rate of change” in the forces produced in “static stability”
Define which axes of the aircraft these stabilities are about
Longitudinal stability about the lateral axis
Lateral stability about the longitudinal axis
Direction stability about the vertical axis
Aircraft with sweep back wings help with what type of stability and why?
Aid in directional stability (when a/c yaws w/wind gust one wing will create more drag than the other?
Wing dihedral aides in what type of stability?
Lateral stability, upward angle of the wing give the aircraft good lateral stability
What is the only environmental factor that speed of sound is dependent on?
Temperature
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, therefore Bernoulli’s principle does not apply to it
Explain what mach number is?
The ratio between the speed of the aircraft and speed of sound
How does an aircraft with sweptback wings affect supersonic flight?
Reduces the chance of air flowing over the wing reaching mach 1, only a component of the wind is flowing on top of the wing to create lift.
What happens to the velocity of the air that has passed through a normal shock wave?
Velocity decreases to subsonic
What are the three types of stability?
Positive: will return the aircraft to it previous attitude
Neutral: will keep the aircraft at whatever attitude it is placed in
Negative: will continue to deviate from the original attitude
What are two types of stability?
Static
Dynamic
What are flight spoilers?
Help with the roll control of an aircraft
Assists the aileron by decreasing the lift on the downward moving wing
Where should the CG be to provide good longitudinal stability?
In front of the center of pressure
