Control

Question 1

In relation to controllability, control surfaces act as…

Answer 1

Destabilisers

Question 2

Combining the tailplane and elevator forms what aircraft part?

Answer 2

Stabilator

Question 3

Combining the rudder and elevator forms what aircraft part?

Answer 3

Ruddervator

Question 4

The downgoing aileron is on the…

Answer 4

Upgoing wing

Question 5

The upgoing wing has what aileron?

Answer 5

Downgoing aileron

Question 6

The upgoing aileron is on the…

Answer 6

Downgoing wing

Question 7

The downgoing wing has what aileron?

Answer 7

Upgoing aileron

Question 8

How is camber affected in a wing whose aileron is downgoing?

Answer 8

Camber increases

Question 9

Increasing camber of a wing does what to its AoA?

Answer 9

AoA increases (and so does the lift and drag)

Question 10

Adverse yaw is yaw in what direction?

Answer 10

Away from the direction of roll

Question 11

Why does adverse yaw occur?

Answer 11

Upgoing wing has greater drag (from greater lift) so pulls aircraft in its direction, away from direction of roll

Question 12

What control surface design can overcome adverse yaw?

Answer 12

Differential ailerons

Question 13

Differential ailerons increase the drag on which aileron and wing?

Answer 13

Upward aileron (descending wing)

Question 14

Differential aileron means the ailerons differ in what way?

Answer 14

The downgoing wing’s aileron deflects at a greater angle than the upgoing wing

Question 15

What type of drag does a differential aileron system increase?

Answer 15

Parasite

Question 16

What kind of aileron involves greater parasite drag by creating disruptive airflow beneath the wing?

Answer 16

Frise-type aileron

Question 17

Frise-type aileron involves what process?

Answer 17

Upgoing aileron’s nose protudes beneath wing and disrupts airflow

Question 18

Secondary effect of the ailerons is…

Answer 18

Yaw

Question 19

Secondary effect or rudder is…

Answer 19

Roll

Question 20

The maximum allowable speed for maximum control deflection is called the

Answer 20

Manouevring speed

Question 21

Manouevring speed is known by what symbol?

Answer 21

VA

Question 22

In-flight, what are the only variables for control effectiveness?

Answer 22

Airspeed and control surface deflection angle

Question 23

Change in turning moment =

Answer 23

Change in lift x Moment arm to CG

Question 24

Change in lift x Moment arm to CG =

Answer 24

Change in turning moment

Question 25

Why does doubling airspeed quadruple thee effect of the control surface deflection?

Answer 25

Aerodynamic forces vary with dynamic pressure so that doubling V will mean the lift coefficient is V-squared

Question 26

Why does slipstream not affect aileron effectiveness?

Answer 26

Ailerons sit outside the slipstream

Question 27

Slipstream affects what control effectiveness?

Answer 27

Rudder and elevator effectiveness

Question 28

What is stick-force?

Answer 28

Moment acting on control surrface trying to return the surface to its original position

Question 29

When deflected, a control surface encounters an opposing aerodynamic force that causes a moment to try and return the surface on its hinge line to its original position. What is thiss called?

Answer 29

Stick-force

Question 30

Stick loads are greatest when...

Answer 30

The hinge line is at the leading edge of the control surface

Question 31

Stick loads increase how?

Answer 31

The further forward the hinge line is on a control surface

Question 32

When reducing stick-load, what aerodynamic process is targeted for reduction?

Answer 32

Hinge moment

Question 33

How is the hinge moment reduced in inset hinges?

Answer 33

Distance between centre of pressure and hinge point is reduced

Question 34

How does a horn balance reduce the overall hinge moment?

Answer 34

The horn moment opposes the hinge moment

Question 35

Downside to horn balance?

Answer 35

Horn balance deflection will increase drag

Question 36

A balance tab moves in what manner?

Answer 36

In opposite direction to the elevator

Question 37

What name is given to a balance tab that is directly connected to the control column?

Answer 37

Servo tab

Question 38

Control surfaces have a tendency to...at high speeds?

Answer 38

Flutter

Question 39

What is a flutter?

Answer 39

Vibration resulting from changes in pressure distribution due to AoA alterations

Question 40

Vibration resulting from changes in pressure distribution due to AoA alterations on a control surface is known as a?

Answer 40

Flutter

Question 41

Mass-balancing aims to reduce/eliminate what?

Answer 41

Fluttering

Question 42

What method is used to reduce/eliminate fluttering?

Answer 42

Mass-balancing

Question 43

Mass-balancing involves placing a mass where?

Answer 43

Forward of the hinge-line

Question 44

Mass-balancing forward of the hinge-line does what to the control surface's aerodynamics?

Answer 44

It brings the control surface's CG forward

Question 45

Over-controlling stabilators are prevented by what aircraft part?

Answer 45

Anti-balance tab

Question 46

An anti-balance tab differs from a balance tab how?

Answer 46

Anti-balance tab moves in the same direction as the control surface's trailing edge, not the opposite

Question 47

Anti-balance tabs provide what to the pilot?

Answer 47

Additional feel

Question 48

Secondary control effect of pitch?

Answer 48

There isn't one