Principles of Flight

Question 1

Static Pressure?

Answer 1

Can be thought as the pressure exerted by the air of atmosphere itself - it is the same in all directions and surrounds a stationary object just as it surrounds a moving object.

Question 2

Dynamic Pressure?

Answer 2

is a pressure caused by the movement of an object through the air or the flow or air past an object.

Question 3

How does a pressure constant work

Answer 3

Static Pressure + Dynamic Pressure is a constant, in other words if dynamic pressure increases, static pressure decreases. This happens for example at the narrowest part of a venture as air moves through

Question 4

Aerofoil?

Answer 4

Cross sectional area of a wing

Question 5

The Chord line?

Answer 5

Straight line through the edge to the trailing edge.

Question 6

The camber of an aerofoil?

Answer 6

Curvature.

Question 7

Angle at which lift acts relative to airflow?

Answer 7

90 degrees.

Question 8

Angle of attack?

Answer 8

The angle between the chord line of the aerofoil and the relative airflow.

Question 9

Centre of pressure?

Answer 9

The point at which the force of lift appears to act. The distribution of lift changes with the angle of attack.

Question 10

As the angle of attack increases?

Answer 10

The centre of pressure moves forward.

Question 11

What is the coefficient of lift?

Answer 11

Measure of the lift generation properties of an aerofoil. As angle of attack increases, the coefficient of lift increases until a certain point (critical staling angle) beyond which the coefficient of lift reduces rapidly.

Question 12

Coefficients of drag?

Answer 12

A measure of the drag generation properties of an object such as an aerofoil. (or aircraft)

Question 13

Wake Turbulence?

Answer 13

Generated by a wing moving through the air, in particular at the wingtips where the airflow from under and over the wing surfaces meet and form a vortex.

Question 14

Which type of aircraft create the most wake turbulence?

Answer 14

The larger, heavier and slow flying aircraft create the most wake turbulence.

Question 15

Parasite drag?

Answer 15

Term used for drag caused by moving an object through the air

Question 16

The ground effect?

Answer 16

This occurs when the aircraft wing is close to the surface (within a height equivalent of one wing span) ground effect modifies the airflow around the wing so that induced drag is reduced and as a result both lift and airspeed will increase, up to a certain point.

Question 17

The Stall?

Answer 17

Occurs when smooth airflow over the wing breaks down and the airflow separates from the wing - this leads to a marked loss of lift and a significant increase in drag.

Question 18

When does the stall occur?

Answer 18

When the wing reaches the critical angle of attack once the angle is reached the wing will stall regardless of airspeed.

Question 19

Lift Augmentation: trailing edge flap?

Answer 19

reduces stall speed and increases both lift and drag. A wing stalls at a shallower stalling angle of attack when flaps are extended.

Question 20

Lift Augmentation: Leading edge slots or slats?

Answer 20

re-energise airflow over the wing, and the wing stalls at steeper greater angle of attack if the wing has slots or slats.

Question 21

the Boundary layer?

Answer 21

Layer of air closest to the surface of a moving object is the boundary layer.

Question 22

where does thin Laminar boundary occurred?

Answer 22

leading edge of the wing where the fluid first meets the object.

Question 23

Where does turbulent boundary occur?

Answer 23

further along the wing as the surface boundary thickens. Creates more drag, however it is less prone to separating from the surface.

Question 24

Static stability?

Answer 24

a measure of how readily an aircraft returns towards its original attitude, following a disturbance

Question 25

dynamic stability?

Answer 25

Measure of how easily the restoring motion caused by static stability is damped out so that the aircraft settles back at its original attitude.

Question 26

positive stability?

Answer 26

returns aircraft to original position.

Question 27

neutral stability?

Answer 27

disturbance gets no worse

Question 28

negative stability?

Answer 28

disturbance increases.

Question 29

differential ailerons?

Answer 29

going up aileron moves through a greater angle than the down-going aileron.

Question 30

where are the limiting load factors?

Answer 30

Aircraft's flight manual / pilots operating handbook

Question 31

Flight load limits: Normal?

Answer 31

3.8

Question 32

Flight load limits: Utility?

Answer 32

4.4

Question 33

Flight load limits: Aerobatic?

Answer 33

+6

Question 34

V-n envelope manoeuvring envelope?

Answer 34

used to set up the limiting factors and airspeeds of the aircraft.

Question 35

V-a airspeed (design manoeuvring speed)

Answer 35

Max speed at which a full and abrupt movement of a flying control can be made without causing structural damage.

Question 36

Slipstream effect?

Answer 36

the spiral corkscrew motion of the propeller slip stream (propwash) creates a force in the vertical tail in particular which yaws the aircraft to the left if the propeller is rotating clockwise.

Question 37

Torque reaction?

Answer 37

The airframe will try to roll in the opposite direction to the propeller rotation, so there will be a rolling motion to the left if the propeller rotates clockwise.

Question 38

Asymmetric blade effect

Answer 38

P-factor, also known as asymmetric blade effect and asymmetric disc effect, is an aerodynamic phenomenon experienced by a moving propeller, that is responsible for asymmetrical relocation of the propeller's centre of thrust when aircraft is at a high angle of attack. creating more thrust on one side. The propeller rotates clockwise, there is yaw to the left.

Question 39

gyroscopic effect?

Answer 39

Rotating blades create a gyroscope. Direction of the force is dependant on where the aircraft is pitched up down left or right.

Question 40

equation straight and level flight?

Answer 40

lift = weight and thrust = drag

Question 41

glide performance calculation?

Answer 41

lift/drag ratio. 10:1 means that the aircraft will travel 10 feet or metres horizontally for every 1 foot or metre vertically.

Question 42

in a 60 degree banked turn the load factor is

Answer 42

2

Question 43

The force that acts perpendicular to the wings in a balanced turn is?

Answer 43

The total lift force

Question 44

Flying controls are mass balanced in order to?

Answer 44

prevent control flutter.

Question 45

A slat or slot on the leading edge of the wing will?

Answer 45

re-energise the airflow over the wing's surface, delaying airflow separation.

Question 46

Yawing is a rotation about the?

Answer 46

Normal axis

Question 47

adverse yaw can be minimised by:

Answer 47

Differential ailerons

Question 48

The fin on an aeroplane?

Answer 48

Increases directional stability

Question 49

The angle between the chord line of an aerofoil section and the relative airflow is the:

Answer 49

Angle of attack

Question 50

Up to the stalling angle of attack. as the angle of attack is increased:

Answer 50

Coefficient of lift increases

Question 51

as the stalling angle of attack is approached, where would a pilot normally expect the airflow to start separating from the wing?

Answer 51

From the trailing edge upper surface.

Question 52

What is the most common reason for design modifications on the wing tip shape?

Answer 52

to reduce induced drag.

Question 53

If an aircraft starts to slip towards a lowered wing, and no corrective action is made by the pilot, the most likely result is?

Answer 53

a spiral decent with increasing bank angle and rate of decent.

Question 54

Horizontal tailplane is designed to

Answer 54

increase longitudinal pitch stability

Question 55

aircraft is at 6000ft and glide range is 6 miles?What is ratio?

Answer 55

6:1

Question 56

in steady climb in a single engine aircraft, the prop is rotating clockwise, slipstream effect will tend to make the aircraft:

Answer 56

Yaw to the lift

Question 57

Indicated stall speeds are ................. at all altitudes.

Answer 57

same

Question 58

In a steady climb on a constant heading:

Answer 58

thrust is greater then drag.

Question 59

To prevent flutter, the control surfaces can be fitted with?

Answer 59

a mass balance

Question 60

In general, as the airspeed increases on an aircraft (in terms of drag)

Answer 60

Parasite drag increases, induced drag decreases.

Question 61

The maximum coefficient of lift occurs?

Answer 61

at around the stalling angle of attack+, beyond which it falls sharply

Question 62

Regarding airflow in the immediate vicinity of an aircraft's wing in normal cruising flight, which of the following statements is correct?

Answer 62

Airflow above the wing will be faster than the free airflow

Question 63

During a level, balanced turn, load factor can be defined as:

Answer 63

Lift divided by weight.

Question 64

When an elevator is moved up, the attached simple trim tab will move:

Answer 64

Remain at a constant angle relative to the elevator.

Question 65

An aircraft wing will stall at a fixed:

Answer 65

Angle of attack.

Question 66

Which of the following conditions will cause an increased stall airspeed?

Answer 66

load factor increased, heavy icing of the wing.

Question 67

if an aircraft is flying at an airspeed faster than Manoeuvring speed (Va) and full up elevator is rapidly applied, the most serious likely result is:

Answer 67

structural damage or failure

Question 68

In relation to ground Effect, a high wing aircraft, when compared to a low wing aircraft, is most likely to:

Answer 68

Experience ground effect at lower hight

Question 69

An aircraft is disturbed from its trimmed attitude, the aircraft then continues to oscillate at a constant rate and magnitude:

Answer 69

Neutral dynamic stability

Question 70

roll, is rotation of the aircraft around it's:

Answer 70

Longitudinal axis

Question 71

To achieve the theoretical max glide range, and assuming nil wind an aircraft should be flown at:

Answer 71

The minimum drag airspeed.

Question 72

Line is drawn through an aerofoil section, from the leading edge to the trailing edge:

Answer 72

chord

Question 73

as the angle of attack is increased, the centre of pressure of the wing:

Answer 73

Moves forward.

Question 74

to remain in straight and level flight and in trim as airspeed increase, it is the most likely that:

Answer 74

the elevator will be deflected down further.

Question 75

when the rudder pedals are operated in-flight, the initial effect is:

Answer 75

yaw around the vertical (normal) axis

Question 76

In general terms Induced drag......... with ........ airspeed?

Answer 76

increases with decreasing airspeed

Question 77

the secondary effect of rudder is

Answer 77

Roll in the same direction as yaw

Question 78

Compared with a zero flap setting, the use of trailing edge flap leads to a:

Answer 78

Reduced stalling angle of attack

Question 79

in level flight an aircraft stalls at 60 knots. In 60 degrees angle of bank turn what would you expect the stalling speed to be.

Answer 79

85knt

Question 80

If aircraft is disturbed from its trimmed attitude, a tendency to return back towards its original attitude is measure of the aircraft's

Answer 80

static stability

Question 81

term that describes aerofoils curvature section?

Answer 81

camber

Question 82

The limiting airspeed known Va represents:

Answer 82

The max speed at which it is safe to violently operate aerofoils without causing structural damage

Question 83

As air flows through the venturi?

Answer 83

the minimum static pressure occurs at the narrowest section.

Question 84

For conventional light aircraft wing, at around 4 degrees angle of attack the wing can be expected to achieve

Answer 84

the max lift/drag ratio

Question 85

What is true about a fixed pitch propeller?

Answer 85

blade or pitch angle is the angle between the blade chord line and the plane of rotation, Blade angle reduced from root to tip Ice on rotating propeller blades will reduce efficiency and may cause vibration.

Question 86

What is most likely to occur as a result of an aircraft on take-off climbing out of 'ground effect'

Answer 86

An increase in induced drag, reduction in lift

Question 87

Normal limiting load factor for operation in the utility category is?

Answer 87

4.4

Question 88

Which way is a propeller spinning if the effect if slipstream and asymmetric blade effect will cause yaw to the left?

Answer 88

clockwise

Question 89

What conditions would reduce stall airspeed?

Answer 89

Altitude and flap setting are reduced

Question 90

With reference to an aircraft wing, what is washout?

Answer 90

An increasing angle of incidence from the wingtip to the wing root.

Question 91

A Frise aileron will:

Answer 91

increase the drag of the descending wing.