M8.3

Question 1

What are the four forces acting on an aircraft?

Answer 1

• lift
• weight
• thrust
• drag

Question 2

What direction does weight always act?

Answer 2

Towards the centre of the earth

Question 3

In theory where does lift, thrust, weight, drag act?

Answer 3

The aircraft centre of gravity

Question 4

What needs to happen for the aircraft to have an equilibrium?

Answer 4

Lift and weight must equal 0 and thrust and drag must equal 0

Question 5

What must the clockwise rotation equal to have an equilibrium?

Answer 5

The anti-clockwise rotation

Question 6

What is a moment caused by?

Answer 6

Forces on a lever that do not act through the point of rotation

Question 7

What is the value of a moment equal to?

Answer 7

Force multiplied by the moment arm

Question 8

What is a moment arm?

Answer 8

It’s the shortest distance between the point of rotation and line of action of the force

Question 9

In reality for steady flight where must the centre of lift be?

Answer 9

Just behind the centre of gravity

Question 10

What is the distance between the centre of gravity and centre of lift known as?

Answer 10

A moment

Question 11

What is the definition of the glide ratio?

Answer 11

The distance forwards to the distance downwards

Question 12

What affects the glide ratio?

Answer 12

All four fundamental forces

Question 13

What is the equation for glide ratio?

Answer 13

Change in sink speed
—————————-
Change in distance

Question 14

What does weight mean to the glide ratio?

Answer 14

The effect of weight varies the time the aircraft will glide for

Question 15

If there are two aircraft wanting to glide with the same characteristics apart from weight, what would happen?

Answer 15

They would cover the same distance but the heavier one would do it first

Question 16

What acts vertically and opposite to weight when an aircraft banks?

Answer 16

Vertical component of lift

Question 17

What acts horizontally to the centre of the turn when an aircraft banks?

Answer 17

Horizontal component of lift

Question 18

What is the horizontal component of lift also known as?

Answer 18

Centripetal force

Question 19

What pulls the aircraft from a straight flight path to make the turn?

Answer 19

The horizontal component of lift

Question 20

What is centrifugal force?

Answer 20

The equal and opposite reaction

Question 21

What must happen for an aircraft to turn?

Answer 21

It must bank

Question 22

How do you stop loosing altitude when making a banked turn?

Answer 22

Increase the angle of attack until lift equals weight

Question 23

What is the load factor?

Answer 23

The proportion between total lift and total weight

Question 24

What is the load factor also called?

Answer 24

G-Load

Question 25

What is the equation for load factor?

Answer 25

N=L/W

Question 26

What do you use to calculate bank angle?

Answer 26

Trigonometric ratio

Question 27

Where does load factor act on the aircraft?

Answer 27

The wings

Question 28

What limits the maximum load factor of an aircraft?

Answer 28

Structural strength and passenger comfort

Question 29

What is the definition of a stall?

Answer 29

The aerodynamic loss of lift that occurs when an aero foil exceeds critical angle of attack

Question 30

What increases when the aircraft bank gets steeper?

Answer 30

The centrifugal force

Question 31

What are the characteristics of a stall?

Answer 31

- pitch down | - roll or yaw to one side

Question 32

What will happen if recovery procedures aren’t initiated after a roll or yaw stall?

Answer 32

The aircraft will go into a spin

Question 33

When do stalls commonly occur?

Answer 33

At slow airspeeds

Question 34

When are stalls most likely?

Answer 34

During approach or departure

Question 35

What information is used in a V-n diagram?

Answer 35

Load factor and equivalent airspeed

Question 36

What factors are each flight envelope dependant on?

Answer 36

- aircraft gross weight - configuration of aircraft - applicable altitude

Question 37

What happens when an aircraft goes past its limit airspeed?

Answer 37

- destructive flutter - aileron reversal - wing divergence

Question 38

What will a large amount of airframe flexing lead to?

Answer 38

A bent airframe or component failure

Question 39

What are structural limits?

Answer 39

The allowed positive or negative amount of G’s

Question 40

Why are structural limits in place?

Answer 40

To ensure flexing wont damage the airframe or shorten design life

Question 41

What are structural limits also referred to as?

Answer 41

Acceleration limits or limit load factors

Question 42

What are aeroelastic limits?

Answer 42

The maximum operating speeds of the aircraft

Question 43

How are the aeroelastic limits indicated?

Answer 43

By knots and mach number

Question 44

What is aeroelastic limits frequently referred to?

Answer 44

The redline airspeed

Question 45

What is the ultimate structural limit?

Answer 45

The point at which damage and failure of components is guaranteed

Question 46

Where about does the ultimate structural limits sit within the operating envelope?

Answer 46

Outside

Question 47

What is the usual aircraft design rule for the ultimate structural limit?

Answer 47

To be 150% of the structural limit

Question 48

Why is airspeed of an aircraft at take-off and landing much less than that at level flight?

Answer 48

For safety reasons

Question 49

As speed is reduced at take-off and landing what needs to happen?

Answer 49

Increase in angle of attack therefore the lift coefficient

Question 50

What are the principle lift augmentation devices?

Answer 50

- flaps - slats - slots

Question 51

What are the different types of flap?

Answer 51

- plain - split - slotted - fowler

Question 52

What are flaps?

Answer 52

Moveable sections of the trailing edge to increase camber of the wing

Question 53

What happens when flaps are deployed?

Answer 53

The increase in camber accelerates airflow on the upper surface to increase lift

Question 54

What is the secondary effect of a flap?

Answer 54

To re-energise the boundary layer

Question 55

What can happen on the plain flap?

Answer 55

Airflow breakaway from the wing surface

Question 56

What the difference between the plain and split flap?

Answer 56

The split flap is less likely to have airflow break away

Question 57

How is a slot formed with a slotted flap?

Answer 57

When the flap lowers a slot is crated

Question 58

How does a fowler flap work?

Answer 58

It moves rearwards and downward which increase wing area and camber

Question 59

What percentage does the maximum lift coefficient increase by when a fowler flap is used?

Answer 59

90%