Controls

Question 1

What type of controls are ailerons

Answer 1

Rate controls

Question 2

What is the formula for the hinge moment (feel)

Answer 2

Hinge moment = f x d

D= distance from centre of pressure of control surface to the hinge

Question 3

What does a insert hinge do

Answer 3

The hinge connecting the control surface is inset slightly closer to the centre of pressure to reduce the force

Question 4

What is the max Inset for a hinge

Answer 4

25% from the leading edge > trailing edge

Question 5

What is a horn balance

Answer 5

Adds area of surface infront of hinge

When elevator is deflected a part deflects in the opposite direction to reduce the force required

Question 6

What % inset is the horn balance limited to

Answer 6

25% of the chord

Question 7

What is a balance tab

Answer 7

Deflects in the opposite direction of the control surface to make movements lighter but less effective

You move control surface which is then linked to the tab

Question 8

What is a anti- balance tab

Answer 8

Works against you

You move control which deflects tab to make controls heavier

Less likely to overstress aircraft

Retaining control feel at low speed

Question 9

What is a servo tab

Answer 9

You move the tab (not the control surface)

Makes controls lighter

High speeds = makes controls lighter

Slow speed = small force produced by tab = controllability issues

Question 10

What is a spring tab

Answer 10

Like a servo tab but with a spring

At slow speeds whole control surface moves as not enough force to stretch spring

High speeds = spring stretches to do the same job as servo tab

Solves the problem of low speed control issues

Question 11

Is a mass balance a aerodynamic balance

Answer 11

NO!!!!!

Question 12

What are the different types of mass balances

Answer 12

Mass in the horn balance

Mass on boom attached to control surface

Arc shaped mass forward of control surface

Question 13

How do mass balances work

Answer 13

Moving the cg of the control surface forward meaning it has a lower inertia (wants to move less)

Question 14

What is the difference between a elevator and a stabilator

Answer 14

Elevator is a camber changing device

Stabilator is a angle of attack changing device

Question 15

When is the greatest risks during s fin stall

Answer 15

Counteracting asymmetric power on a Engine failure on multi engine aircraft

Question 16

What direction does the raf need to come from to produce a positive angle on the rudder

Answer 16

Raf from the right = positive

Question 17

If ailerons are rate control what is rudder and elevator

Answer 17

Displacement

Question 18

What causes aerodynamic damping

Answer 18

Higher AOA on down going wing = more lift

Lower AOA on up going wing = less lift

Question 19

If you roll right what was do you yaw

Answer 19

Left

Question 20

What are frise ailerons

Answer 20

Down going wing = aileron up = leading edge of aileron protrudes below = drag = helps counter adverse aileron yaw

Question 21

What are differential ailerons

Answer 21

down going wing aileron deflects more than up going going = more drag = helps reduce aileron yaw

Question 22

How do large aircraft control adverse aileron yaw

Answer 22

Frise ailerons

Spoilers

Control coupling

Question 23

What would happen if the outboard ailerons were used at high speed on a large jet

Answer 23

Wing twist = adverse aileron yaw

Question 24

How do spoilers help stop adverse aileron yaw

Answer 24

Down going wing = spoilers up a bit to create more drag

Question 25

What are the advantages of spoilers as roll control

Answer 25

Don’t suffer from flutter

Leave tailing edge free for flaps

Cause no twisting moment

Question 26

What is a flaperon

Answer 26

Aileron can drop slightly to give the effect of s flap

Question 27

What is control coupling

Answer 27

Where a mixer unit interconnects the inputs from the control column and the rudder peddle

Question 28

What are the advantages of a trimmable horizontal stabiliser

Answer 28

More aerodynamically effective (less drag)

Enables equal pitch up and down control about any trimmed position

Control over a greater cg range

Less sensitive to flutter

Question 29

What may help a Jamed stabiliser

Answer 29

Reducing speed might help by reducing the size of the out of trim force but will also reduce effectiveness