Flight controls

Question 1

An ailerons that has greater up travel than down travel are what type of ailerons?

Answer 1

Differential ailerons

Question 2

If an aircraft doesn’t have a tail-mounted elevator or horizontal stabilizer, what might the aircraft have instead that does the same job?

Answer 2

Canards

Question 3

Why does a canard reach the stall point prior to the wings?

Answer 3

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

Question 4

What type of wings are used if lateral stability is excessive and the aircraft is hard to maneuver?

Answer 4

Anhedral wings

Question 5

What are the 3 primary flight controls?

Answer 5

Ailerons (roll)
Elevators (pitch)
Rudder (yaw)

Question 6

What is adverse yaw?

Answer 6

When the nose turns in the opposite direction of the intended banked turn

Question 7

Name 3 ways to minimize adverse yaw

Answer 7

Differential aileron travel
Frise aileron
Automatic rudder

Question 8

Explain how the elevator works in flight (control, direction of travel, A/C reaction)

Answer 8

Elevator attached to horizontal stabilizer, stabilizer/elevator forms airfoil.

Control wheel FWD, elevators down, nose pitches down (tail up)

Question 9

Define stabilator

Answer 9

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

Question 10

What is static stability?

Answer 10

Tendency of the aircraft to try to return to straight and level flight

Question 11

What is dynamic stability?

Answer 11

Is the “rate of change” in the forces produced in “static stability”

Question 12

Define which axes of the aircraft these stabilities are about

Answer 12

Longitudinal stability about the lateral axis

Lateral stability about the longitudinal axis

Direction stability about the vertical axis

Question 13

Aircraft with sweep back wings help with what type of stability and why?

Answer 13

Aid in directional stability (when a/c yaws w/wind gust one wing will create more drag than the other?

Question 14

Wing dihedral aides in what type of stability?

Answer 14

Lateral stability, upward angle of the wing give the aircraft good lateral stability

Question 15

What is the only environmental factor that speed of sound is dependent on?

Answer 15

Temperature

Question 16

Explain how supersonic airflow is different from subsonic airflow

Answer 16

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

Question 17

Explain what mach number is?

Answer 17

The ratio between the speed of the aircraft and speed of sound

Question 18

How does an aircraft with sweptback wings affect supersonic flight?

Answer 18

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.

Question 19

What happens to the velocity of the air that has passed through a normal shock wave?

Answer 19

Velocity decreases to subsonic

Question 20

What are the three types of stability?

Answer 20

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

Question 21

What are two types of stability?

Answer 21

Static
Dynamic

Question 22

What are flight spoilers?

Answer 22

Help with the roll control of an aircraft

Assists the aileron by decreasing the lift on the downward moving wing

Question 22

Where should the CG be to provide good longitudinal stability?

Answer 22

In front of the center of pressure