Controls

Question 1

Elevator pitches around the

Answer 1

Lateral axis

Question 2

Rudder yaws around

Answer 2

Normal axis

Question 3

Ailerons roll around

Answer 3

The longitudinal axis

Question 4

Problems with controls at high speeds

Answer 4

Large control surfaces produces high control forces

Question 5

How speed effects controls

Answer 5

Larger control movements at high speed are physically hard for the pilot than at slow speed

Question 6

7 Types of aerodynamic balances

Answer 6

Modify forces on the control surface
Inset hinge 
Horn balance 
Internal balance 
Balance tab 
Anti balance tab
Servo tab 
Spring tab

Question 7

Inset hinge

Answer 7

Hinge moment distance is reduced
Reduced feel
Reduced work on the control column
Max distance from the fwd hinge is 25%

Question 8

Horn balance

Answer 8

Reduces the amount of force on the surface
Make the controls lighter and more effective
Forces hold the control in place

Question 9

Internal balance

Answer 9

Sealed internal gap
Pressure differential causes an assist with the hinge moment
Reduces control column forces

Question 10

Balance tab

Answer 10

Manual balance
Deflects in the opposite direction
Not very efficient due to going in the opposite direction
Make control surfaces lighter
Reduces the load felt at the control column
Reduces control effectiveness

Question 11

Anti balance tab

Answer 11

Makes control surfaces heavier
The tab moves with the control surface
Improves efficiency
Less possibility of over stressing at higher speeds

Question 12

Servo tab

Answer 12

Pilot is connected to the tab itself
Move and it creates an aerodynamic force which moves the tab in the opposite direction
Control authority decreases at slow speeds
Very effective at high speeds
Not very effective at slow speeds with small aerodynamic forces being produced

Question 13

Spring tab

Answer 13

Acts like a servo tab at high speed

Acts like a balance tab at slow speeds

Question 14

Mass balancing

Answer 14

Adding masses ahead of the hinge line to reduce flutter

Question 15

Power assisted controls

Answer 15

Still some natural feel but mostly powered

Question 16

Fully powered controls and how to avoid the risks

Answer 16

No feedback
Artificial feel is required
Provide all the power to move control surfaces

Q feel system generates artificial forces in proportion to dynamic pressure

Question 17

AoA in a roll

Answer 17

Downgoing is greater

Up going is reduced

Question 18

Aerodynamic damping in the roll

Answer 18

The up going wing is producing more CL which is creating more Di which is forcing the a/c to yaw in the opposite direction

Longer wings increase this

Question 19

Variable incidence tailplane

Answer 19

Whole a/c tailplane moves 
Common on jet a/c
Creates a large pitching moment 
Greater aileron authority 
Leading edge down, pitch up 
Leading edge up, pitch down

Question 20

High T tail

Answer 20

Improves L/D ratio 
Stays out of downwash 
Ground effect reduces
Heavier structural requirements on the tail 
Could go into the deep stall

Question 21

Rate controls

Answer 21

Ailerons

Question 22

Displacement controls

Answer 22

Rudder

Elevator

Question 23

Frise ailerons

Answer 23

Reduces adverse aileron yaw

Increases parasite drag on the downgoing wing to counteract the induced drag on upgoing

Question 24

Differential ailerons

Answer 24

Upgoing aileron deflects less than the downgoing and produces more drag to counteract the adverse aileron yaw

Question 25

Secondary effects of the rudder, aileron and elevator

Answer 25

Rudder - roll
Aileron - sideslip the yaw
Elevator - none

Question 26

Using a servo tab and during the flight the elevator jams, what happens the pitch control

Answer 26

Pitch control sense is reversed due to the controls being attached to the tab

Question 27

When trimmed fo 0 stick force, what causes less drag

Answer 27

Horizontal trimmable stabiliser than a trim tab

Question 28

On a trim tab runway what causes less control difficulty

Answer 28

Trim tab runway compared to a horizontal trimmable

Question 29

Stabiliser trim and flutter

Answer 29

Less sensitive to it

Flutter is also dependant upon IAS

Question 30

Difference between trim tab and servo tab

Answer 30

Trim tab reduces stick force to 0

Servo tab reduces stick force