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PPL aircraft tech > Cards > Flashcards

Cards Flashcards

1
Q

Describe the affect of Windshear on take off and landing?

A

Causes fluctuations in IAS.

Decrease in IAS creates sink,

an increase creates float,

If you were flying into a headwind, and then it suddenly changed into a tailwind, your IAS would decrease.

You would lose altitude until you made adjustments.

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2
Q

Describe what happens to the centre of pressure as the Angle of Attack is increased to maintain lift?

A

The lift envelope is modified forward until the critical angle of attack, where it rapidly moves to rearward.

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3
Q

Where does lift act from?

A

Centre of pressure

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4
Q

Describe an ideal fluid?

A

No viscosity, incompressible. Above 250kts it begins to compress

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5
Q

Describe Bernoulli’s Theorem

A

In a streamlined flow of an ideal fluid or gas (one that is not viscous), the sum of all energy of position, the energy of motion, and the energy, will remain constant

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6
Q

Lift Formula

A

Lift = CL 1/2pv2 S

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7
Q

What is dynamic pressure? Formula terms

A

Equates to IAS. 1/2pv2

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8
Q

What is the camber and angle of attack? Lift formula

A

CL

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9
Q

Atmospheric Table

A

TIDD
PDDD
HIDD
HIDD

Temp+, Density-
Pressure-, Density-
Humidity+, Density-
Height+, Density-

Density decreases when all but pressure increases, where in that case, when pressure decreases so too does density. Pressure is the only factor that decreases density when it too decreases. Everything else is opposite.

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10
Q

Describe the effect of climb on the carburettor?

A

Air density decreases with altitude so as we climb, less air is drawn through the carb into the cylinders. Regardless of altitude, pistons try to draw a full charge of fuel/air into the cylinders.

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11
Q

Describe what happens to the fuel mixture at a higher altitude?

A

As air supply decreases, a disproportionate amount of fuel is drawn into the cylinders. Simply, the mixture becomes enriched.

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12
Q

What power setting delivers an excessively rich mixture?

A

Full throttle

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13
Q

What happens when the mixture control is retarded?

A

A partial leaning of the mixture occurs. If retarded all the way, the flow of fuel to the carburettor will be stopped.

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14
Q

List the causes of detonation

A

Prolonged use of high power
Incurred use of high manifold pressure
Mixture too lean
Incorrect use of carb heat
Engine overheating
Using incorrect grades of fuel

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15
Q

Symptoms of detonation

A

Significant or severe vibration and rough running
Loss of power
Rapid rise in cylinder head temperatures
Destruction of component parts

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16
Q

What does extra fuel help with in the engine, considering a fully enriched mixture?

A

Cooling

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17
Q

Fuel Grades and Types
Specify the colour and equipment colour

A
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18
Q

Describe the weak, optimal and overly rich mixture ratios?

A

Weak: 15:1 to 20:1
Optimal: 13:1
Overly rich: 8:1 to 10:1

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19
Q

Effects of a weak mixture

A

Overheating
Rough running
Loss of power
Detonation
Pre ignition

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20
Q

Effects of an overly rich mixture

A

Rough running
Loss of power
Excessive fuel consumption
Black smoke

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21
Q

If your fuel type is unavailable, what is the correct fuel type to use? Why is this important?

A

A grade higher than your grade. Don’t use a lower grade. This can cause detonation.

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22
Q

Describe action steps to take if rough running occurs

A

When experiencing rough running in a Cessna 172, follow these steps to diagnose and address the issue:

  1. Check Magnetos:
    • Switch between left and right magnetos to see if one is causing the problem.
    • Run on both magnetos if one is noticeably rougher.
  2. Adjust Mixture:
    • Lean the mixture if the engine is running too rich (high density altitude).
    • Enrich the mixture if the engine is running too lean.
  3. Carburetor Heat:
    • Apply carburetor heat to check for ice or frost blockage. If the engine runs better after applying carb heat, there may have been ice in the carburetor.
  4. Throttle Adjustment:
    • Adjust the throttle slightly to see if the roughness changes with RPM variations.
  5. Fuel Selector:
    • Ensure the fuel selector is set to BOTH tanks.
  6. Fuel Quantity and Quality:
    • Check fuel quantity in both tanks.
    • Ensure fuel caps are secure.
    • Ensure fuel is free from water and contaminants.
  7. Check Engine Gauges:
    • Verify all engine gauges (oil pressure, temperature, etc.) are in the normal range.
  8. Spark Plugs:
    • Consider fouled spark plugs, especially if the engine was idling for a long time.
  9. Examine Air Intake and Filters:
    • Ensure the air intake is clear.
    • Check air filters for blockages.
  10. Maintenance Issues:
    • After landing, consult a mechanic to check for more in-depth issues, such as valve problems or cylinder compression issues.

If the rough running persists despite these checks, consider landing at the nearest suitable airport and consulting a mechanic before continuing the flight. Safety should always be the primary concern.

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23
Q

What are the two major parts of an altimeter?

A

An airtight case
An aneroid capsule

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24
Q

What does the altimeter do?

A

Indicates the height of the aircraft with reference to a datum or pressure level.

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25
Q

What does the altimeter do?

A

Indicates the height of the aircraft with reference to a datum or pressure level.

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26
Q

How does the altimeter read?

A

Static pressure is fed into the altimeters airtight case. One side of an evacuated capsule is attached to the case of the instrument. The capsule is evacuated as fully as possible to help avoid back pressure when the capsule contracts. A spring holds the capsule in tension to help the expansion of the capsule as pressure reduces in the case.

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27
Q

Relationship of climbing and descending on the altimeter?

A

Climb= static pressure in the case decreases allowing the capsule to expand

Descends= static pressure increases causing the capsule to contract

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28
Q

When on the ground, when ISA deviation occurs, what will happen to the altimeter?

A

It will show a change in altitude on the altimeter. We can adjust the altimeter to give the correct reading above a certain datum (usually sea level).

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29
Q

Describe magnetic dip
Consider the poles

A

At the poles, the magnetic field is vertical; at the equator, it is horizontal to the earths surface. In between, the magnetic field cuts the earths surface at different angles. Because of this, the earths magnetic field at any point can be expressed as a horizontal (H) and vertical (Z) component.

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30
Q

Describe magnetic dip angle
Centre of gravity, point of suspension, weights

A

Magnetic dip angle is the angle between the horizontal and vertical component. To maximise the horizontal component of flux, the compass has a high point of suspension and a low centre of gravity. To account for the vertical component, a weight is used, thus the angle of dip (dipping effect due to the Z component of the earths magnetic field) is reduced.

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31
Q

What is the remaining dip in magnetic dip?

A

It is known as residual dip

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32
Q

Describe what an AHRS (Altitude and Heading Reference System) is

A

It’s a solid state, 3 axis system that provides heading, attitude and yaw information for aircraft.

It replaces traditional group of mechanical gyroscopic flight instruments and it provides superior reliability and accuracy.

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33
Q

Describe Vibrating Structure Gyroscopes

A

Also known as MEMS (micro electro mechanical systems) gyroscopes. At a reasonable cost, they are small, light units designed to perform with better accuracy and durability than traditional gyroscopes with rotors and bearings. As such, they are ideally suited for use in an EFIS (Electronic Flight Instrument System)

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34
Q

Describe the effects of flaps on lift

A

Lowering the flaps produces an increase in.

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35
Q

Explain the requirement for balancing of controls

A

By applying a weight to the front of the hinge of the control, the moment of the weight in front of the hinge balances the moment of the weight of the actual control behind the hinge.

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36
Q

Describe flutter

A

Flutter is an unstable vibration/oscillation of a control surface and the control surface structure.

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37
Q

Describe a balance tab

A

Completing or partially balance the aerodynamic load on the control surfaces, thus reducing the control wheel force (i.e assisting the pilot).

It is not controlled by the pilot, but the table angle is changed automatically whenever the main control surface is moved.

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38
Q

CP Movement for Symmetrical Aerofoils

A

A symmetrical aerofoil has identical upper and lower surfaces.

In a symmetrical aerofoil, the CP remains relatively constant with changes in the angle of attack. It typically stays near the aerodynamic center, which is around the quarter-chord point (25% of the chord length from the leading edge).

Because the lift generated is symmetrical about the chord line, the CP does not shift significantly with changes in angle of attack. This makes symmetrical aerofoils more predictable in terms of stability.

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39
Q

CP Movement of Non Symmetrical Aerofoils

A

A non-symmetrical or cambered aerofoil has a curved upper surface and a flatter lower surface.

In a non-symmetrical aerofoil, the CP shifts more noticeably with changes in the angle of attack. At low angles of attack, the CP is further forward, but as the angle of attack increases, the CP moves rearward.

The CP movement is more pronounced because the lift is not symmetrical about the chord line. As the angle of attack increases, the changing pressure distribution causes the CP to shift, impacting stability and control.

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40
Q

Define Static and Dynamic Pressure

A
  • Static Pressure (Ps): The pressure exerted by a fluid at rest or the pressure of the fluid’s environment.
  • Dynamic Pressure (Pd): The pressure associated with the fluid’s motion, calculated half rho v2, where rho is the fluid density and v is the fluid velocity.
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41
Q

Describe the effect of an increase in airflow on Static & Dynamic Pressure

A
  1. Static Pressure (Ps):
    • Decreases.
    • As the airflow speed increases, the kinetic energy of the air particles increases, leading to a decrease in static pressure according to Bernoulli’s principle.
  2. Dynamic Pressure (Pd):
    • Increases.
    • Dynamic pressure is directly proportional to the square of the velocity. Hence, as the speed of airflow increases, the dynamic pressure increases significantly.
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42
Q

Describe the effect of a decrease in airflow on Static and Dynamic Pressure

A
  1. Static Pressure (Ps):
    • Increases.
    • As the airflow speed decreases, the kinetic energy of the air particles decreases, causing an increase in static pressure.
  2. Dynamic Pressure (Pd):
    • Decreases.
    • With a decrease in airflow speed, the dynamic pressure, being proportional to the square of the velocity, decreases.
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43
Q

Imagine an Aerofoil. Describe airflow over the aerofoil.

A
  • At point A (leading edge), air splits, flowing over and under the aerofoil.
  • At point B (upper surface), airflow speeds up, static pressure decreases, and dynamic pressure increases.
  • At point C (lower surface), airflow is slower, static pressure increases, and dynamic pressure decreases.
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44
Q

Describe the forces for load on aircraft wings

A

In flight: Lift
Hard landing: Force down

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45
Q

Describe the effect of compression on the braces of a wing for a High Wing and Low Wing aircraft

A

High Wing: the aircraft is trying to stretch the braces and; shock is transmitted through the braces to the wing structure on a hard landing.

Low wing: the aircraft is trying to fold the braces against the strut and; shock is transmitted through the braces to the fuselage

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46
Q

Compression/Tension on High Wings and Low Wings

A

HW:
In flight: tension
LW:
In flight: compression

Opposite for hard landings

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47
Q

What creates Proeller slipstream? Power or airspeed?

A

Power

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48
Q

What improves the effects of ALL controls?

A

Increasing airspeed

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49
Q

Increasing power increases ___ and ___ effectiveness

A

Rudder
Elevator

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50
Q

If the engine is overheating on the ground, what action should you take?

A

Run the engine at the specified RMP

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51
Q

What happens to the gyroscopic instruments if the vacuum is reduced below limits?

A

Turn indicator: Under-read in a turn due to the reduced gyroscopic rigidity at the lower RPM

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52
Q

Pseudo Random Codes determine the __ of a __ satellite

A

RANGE
GNSS

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53
Q

Define Moment Arm

A

The distance between the point at which a force is being applied and the pivot point (fulcrum)

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54
Q

What is the function of the idle jet in a carburettor?

A

Provide extra fuel at low RPM when the main jet fuel becomes unreliable

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55
Q

How many satellites does the GPS system generally consist of?

A

24 or more with 3 operational spares

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56
Q

GPS positions relate to maps and charts drawn to which global datum?

A

WGS 84

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57
Q

Define Lateral Axis
Around what centre
And what aircraft movement

A

Wing tip to wing tip along the CofG which aircraft pitches around

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58
Q

Define Basic Empty Weight [of aircraft]

A

Airframe, engines, full oil, unusable fuel and fitted equipment

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59
Q

What information does the Air Data Computer take?

A

Static pressure
Pitot pressure
Air temp from the TAT head or OAT probe
Angle of attack from the AOA probe (if required)

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60
Q

What occurs with instruments when there is no suction OR electricity? (gyroscopic instruments)

A

Topple and a flag will show.

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61
Q

Define Plane of Rotation (prop)

A

The rotational velocity of the blade section

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62
Q

Define Angle of Attack

A

The angle between relative airflow and the chord line

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63
Q

Define Blade Angle (prop)

A

The angle between plane of rotation and chord line

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64
Q

Define Helix Angle (prop)

A

The angle between plane of rotation and relative airflow

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65
Q

Symptoms of pre-ignition

A

Rough running
Loss of power
Overheating

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66
Q

What is pre-ignition?

A

The fuel/air charge that has just been drawn into the cylinder and is being compressed, then ignited, before the spark occurs.

There has to be something red hot inside the cylinder.

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67
Q

Calculate Pressure Altitude

A

e = Elevation
q = QNH
p = pressure altitude

q1 - q2 = x hPa

x hPa x 30ft = x ft

e -/+ x ft = pressure altitude

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68
Q

If QNH is lower than ISA (1013 hPa), then the pressure altitude is _____ than elevation and the aircraft will perform as though it were at a _____ altitude. (performance ______)

A

Higher
Higher
Decreases

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69
Q

Calculate Density Altitude

A

E = elevation
Q = QNH
P = Pressure altitude
T = Temperature deviation
D = Density Altitude

Calculate ISA temperature deviation
Isa deviation = 15 degrees - (2 x pressure altitude to nearest 500ft/1000)

Isa dev temp * 120 ft / 1 degree of temperature deviation = x

Density altitude = pressure altitude + x

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70
Q

Density Altitude Fast Formulas

A
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71
Q

Describe a Monocoque Airframe

A

Skin carried all forces and stresses during the flight without assistance from reinforcing members.

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72
Q

Describe a semi-monocoque airframe

A

Reinforced with bulkheads, rings, stringers. Strong and rigid fabrication. Stressed metal skin adds strength and carried a large % of the load.

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73
Q

Formula for Moment

A

Weight x Arm = Moment

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74
Q

Define Station (STA)

A

Position relative to the datum from which it is being measured

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75
Q

What can destroy a fabric covered airframe?

A

Constant exposure to heat and moisture over time

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76
Q

What to look for in a preflight of aluminium airframes?

A

Corrosion
Bubbling or flecking of paint

77
Q

Risks of composite aircraft?

A

Can crack easily on impact

78
Q

Give the benefit of a finer Propellor pitch during takeoff?

A

Finer pitch gives a higher RPM and improves takeoff performance

79
Q

What tool sensed direction of the earths magnetic field? Tip: it’s in the compass

A

A magnetometer

80
Q

Does a compass lead or lag in the southern hemisphere?

A

Lags

81
Q

How many degrees per second in a rate 1 turn?

A

3

82
Q

When does pre-ignition occur?

A

Before the spark plug provides a spark plug

83
Q

When does detonation occur?

A

After the spark

84
Q

What is Joshua’s mnemonic for detonation and pre ignition?

A

Detonation after the spark - think fireworks and explosions!

Pre ignition before the spark plug provided a spark, because we’re just getting ready!

85
Q

What is Joshua’s mnemonic for detonation and pre ignition?

A

Detonation after the spark - think fireworks and explosions!

Pre ignition before the spark plug provided a spark, because we’re just getting ready!

86
Q

Why does the an aircraft have two magnetos?

A

Generates more efficient combustion and as a backup in case of failure during flight

87
Q

List the four functions of engine oil

A

Lubricate
Cool
Clean
Seal

88
Q

What happens to the flow of oil if oil pressure is too high?

A

It flows through the engine too fast

89
Q

Causes of low oil pressure

A

Insufficient oil
Leaks in the tank or system
Engine bearings in poor condition
Pressure relief valve stuck open

90
Q

Define Maximum All Up Weight

A

The maximum weight at which the aircraft is allowed to fly. This is AKA Gross Weight

91
Q

Define Zero Fuel Weight

A

The weight of the aircraft excluding fuel.

92
Q

What are the function of ribs in the empennage?

A

Provide additional support

93
Q

List what is in the empennage

A

Stabilizers (H and V)
Elevators
Rudder

94
Q

Define Centripetal force

A

Inward seeking force

Mass x Velocity2 (v2) / radius

95
Q

Define Streamline Flow

A

Any airflow following a predictable path without mixing of any air molecules

96
Q

Aircraft Cylinder Configurations

A

Radial
In-line
Inverted
Horizontally opposed
V arrangement
Rotary

97
Q

What does the internal combustion piston engine consist of?

A

A cylinder that is closed at one end, a piston that slides up and down inside the cylinder, and a connecting road and crank by which reciprocating movement of the piston is converted to rotary movement of the crankshaft

98
Q

What is the closed end of the cylinder also known as?

A

The cylinder head

99
Q

What is contained within the cylinder head?

A

Inlet and exhaust valves and two sparking plugs.

100
Q

Summary of the Induction Stroke (IPPA)

A

IPPA

Inlet valve open
Piston descends
Pressure lowers
Air and fuel drawn in

101
Q

Summary of the Compression Stroke (PIMPT)

A

PIMPT

Piston moves upwards
Inlet valve closes
Mixture compressed
Pressure increases and continues to increase while burning
Top dead centre(TDC) and bottom dead centre (BDC)

102
Q

Summarise the Power Stroke

A

Just before the piston reached TDC on the compression stroke, spark ignited the highly atomised mixture

Flame spreads through the combustion chamber

Intense heat raised the pressure rapidly

10degrees pasted TDC: peak value reached

Pressure falls as piston forced down

103
Q

Summarise the Exhaust Stroke (EPFEC)

A

EPFEC

Exhaust valve open
Piston ascends forcing out spent gasses
Free flowing as possible
Exhaust valve closed
Cycle begins again

104
Q

What is the Otto Cycle?

A

Induction
Compression
Power stroke
Exhaust

105
Q

What is the crankcase

A

Houses the major engine components and also stores oil in some cases

106
Q

What is the camshaft

A

Operates the inlet and outlet valves and is geared to the crankshaft

107
Q

Describe valve timing

A

When a valve is nearly closed , not much charge can enter the cylinder, so in order not to waste any part of the induction and exhaust strokes, the valve begins to open earlier and finally close later than expected

Valve lead
Valve lag

108
Q

What happens when the throttle is opened?

A

A greater amount of mixture is admitted into the intake manifold and then into the combustion chamber

109
Q

Define density

A

The degree of compactness of a substance

110
Q

What are the two main types of fuel injection systems?

A

Low pressure / continuous flow systems or indirect injection

High pressure or direct injection systems

111
Q

Advantages of Fuel Injection systems

A

Freedom from refrigeration icing because of order of components

Uniform delivery of fuel/air mixture to each cylinder

Improved control of fuel-air ratio

Reduced maintenance

Quick response for acceleration

Increased engine efficiency

112
Q

Disadvantages of a fuel injection system

A

Vapour locks

Need for electric boost pump

Greater suspect ability to contamination

Greater need for awareness of fuel distribution; excess fuel may be returned to one tank

113
Q

What is vapour lock?

A

Vapor lock happens when the fuel in your fuel lines vaporizes, turning from a liquid to a gas. In other words, your fuel has boiled. When your fuel lines are full of vaporized 100LL, your fuel pump can’t get liquid fuel to the injector nozzles, which makes starting your aircraft frustrating, difficult, or impossible.

114
Q

Pressure source for a Fuel Injection system

A

Injection pump

115
Q

How is fuel discharged in a Continuous flow, fuel injection system?

A

Directly into the inlet manifold immediately outside the inlet valve port

Regulated by the throttle butterfly valve

116
Q

In a continuous flow system for fuel injection, what does the Venturi do?

A

Weighs the air, enabling the fuel control unit to discharge the correct amount of fuel into the inlet manifold just prior to the inlet valve, maintaining the correct ratio

117
Q

Describe system components of a Direct Injection System
Fcu
DumP
Discharge
H

A

Fuel control unit
Delivery pumps
Pump synchroniser
Discharge nozzle in each cylinder
High pressure lines

118
Q

Explain the fuel control unit

A

Mounted in place of the carb, measures airflow and meters fuel to the injection pumps

The discharge nozzle contains a spring poppet valve which sprays fuel directly into the combustion chamber.

119
Q

What is an Impulse Coupling

A

The impulse coupling retards and boosts spark

120
Q

What is the function of the impulse coupling?

A

Usually fitted to the left mag only, used for easier starting

121
Q

Describe how impulse coupling works

A

When the key is switched to Start, the right magneto is disengaged; the engine starts on left only.

If the engine needs to be hand started the engine should be selected to the left mag only to prevent kick back

122
Q

What type of connection is the impulse coupling?

A

A mechanical connection

Spring loaded, it winds up as the engine is turned over by the starter before releasing at a given mechanical point

This in effect, retards the ignition timing.

When the spring is released, the magneto spins at a much higher speed, generating a higher voltage to aid starting

123
Q

Why should rapid power changes be avoided in all phases of flight?

A

Damage to components can occur, reducing the life of the engine

124
Q

What is the most common source of rough running?

A

Overly rich mixture

125
Q

What is the basic steps to take if rough running occurs?

A

Lean the mixture until power is restored. If it isn’t restored, consider a precautionary landing or divert to the nearest aerodrome.

126
Q

What do most light aircraft use for their electrical systems? AC or DC

A

DC

127
Q

What is an ammeter?

A

An ammeter or load meter alerts the pilot when the generator or alternator is inoperative or malfunctioning

128
Q

What does an ammeter measure?

A

Electrical current

129
Q

What does a negative indication on an ammeter indicate?

A

Failing to supply sufficient power - or worse, the alternator has failed altogether

130
Q

What should a pilot avoid using on the ground to preserve battery (prior to start

A

Pitot heat
Landing and taxi lights
Avionics
Avoid leaving master switch on for a prolonged period of time

131
Q

What happens to the viscosity of oil as it heats up? What then happens to the flow?

A

It decreases. This then results in an increase in the speed at which it flows through the engine and cooling ability reduced accordingly

132
Q

Describe high viscosity oil

A

Thick and has a high resistance to flow

133
Q

Describe low viscosity oil

A

Thin and flows more freely

134
Q

Describe how oil supports with sealing?

A

Oil helps to maintain a gas tight seal over a wide range of operating temperatures, compensating for the different expansion rates of the piston and cylinder

135
Q

How is oil viscosity measured?

A

With a viscosimeter.

E.g SAE10: low viscosity
SAE80: high viscosity

136
Q

Impact of using the wrong grade of oil

A

Poor lubrication
Overheating
Wrong oil pressure
Engine damage

137
Q

Effects of incorrect oil level

A

Excess: forced through various parts of the engine
Insufficient: begin to overheat

138
Q

What does the combination of low or fluctuating oil pressure combined with a rise in oil temperature, indicate?

A

A serious problem, land as soon as possible. If oil runs out, the engine will seize.

139
Q

The balance section of the turn indicator (TI) and turn coordinator (TC) respectively utilizes a…

A

Ball in a glass filled with liquid

140
Q

In a skipping turn, the ball will

A

Be inside the lower end of the tube (right side)

141
Q

What factors effect the Coefficient of Lift (Cl)

A

Camber (shape) and angle of attack

142
Q

What is the main disadvantage of a thick aerofoil?

A

Increased drag is generated as speed is increased

143
Q

What effect does surface area of a wing have on lift?

A

The greater the surface area, the greater the lift produced

144
Q

Describe the three forces in a glide descent

A

In a glide, the forces are balanced. But as the engine is providing no thrust, there are only three forces to balance:
- lift
- drag
- weight

145
Q

Describe the effect of flap in a glide descent

State the nose attitude

A

Increases drag which decreases airspeed.

The nose attitude must be lowered which increases the angle of descent

Range and endurance decreases

146
Q

Wind has no effect on ___.

It has an effect on ____.

A

Rate of descent
Range

147
Q

Example of headwind vs nil wind vs tailwind on range

A
148
Q

In a straight and level flight, lift is equal to weight, and the load is said to be ____ G, or ____ times the normal acceleration due to gravity

A

1
1

149
Q

What is the temperature lapse rate for density altitude?

A

A 1 degree change in temperature = a 120 ft change in density altitude

150
Q

Newtons First Law

A

Every object will continue in a state of rest or uniform motion in a straight line unless an external force acts upon it

151
Q

Newtons Second Law

A

The external force acting on a body is proportional to the product of its mass and the acceleration produced by the force

152
Q

Newtons Third Law

A

For every action, there is an equal and opposite reaction

153
Q

Force =

A

Mass x Acceleration

154
Q

Weight =

A

Mass (m) x Gravity (g)

155
Q

Work =

A

Force (f) x Distance (d)

156
Q

Power (p) =

A

Work / Time

157
Q

Speed is a ______ quantity, thus it does not have direction

A

Scalar

158
Q

The measurement of temperature is, in effect…

A

A measure of the rate of movement of molecules of the subjects substance

159
Q

An increase in pressure effectively….

A

Squeezes a given parcel of air thereby reducing its volume, this will increase the number of molecules in a given volume, and increase its density

160
Q

The density of any object is defined as…

A

Mass per unit volume,

161
Q

As the angle of attack increases, what happens with drag?

A

It also increases

162
Q

What is the critical / stalling angle?

A

15 degrees

163
Q

What is the critical / stalling angle?

A

15 degrees

164
Q

Effect of ice or damage on lifting capability

A

Airflow over the wing cannot adhere to the wing to remain a laminar flow.

Reduction in production of lift occurs

165
Q

Drag increases at a rate proportional to the ____ of the airspeed

A

Square

166
Q

The Drag Tree

A
167
Q

Define Induced drag

A

Lift dependent drag. Whenever the wings are producing lift, induced drag is also produced

168
Q

Define Parasite Drag

A

Drag that is not inherent to the production of lift. It is the sum of form drag, skin friction, interference and cooling drag.

169
Q

Define Cooling Drag

A

Arises from air flowing over radiators, around cylinder, and through cowlings

170
Q

Define interference Drag

A

The airflow over one surface can upset the flow over the other, Which causes a mixing of the airflows, creating eddies and turbulence

171
Q

Define Profile Drag

A

Profile drag is a combination of skin friction drag and form drag

172
Q

Define Profile Drag

A

Profile drag is a combination of skin friction drag and form drag

173
Q

Define Yaw

A

Yaw is about the vertical axis and is controlled by the rudder

174
Q

Define roll

A

Roll is about the longitudinal axis and is controlled by the ailerons

175
Q

Effect of flap on approach

A

The high drag of a fully lowered flap allows the aircraft to have a steeper angle without the speed increasing - it has the effect of an air brake

176
Q

Lift/weight forces are greater than thrust/drag forces by approximately ….

A

10:1

177
Q

On a power available/power required graph, list the order on the lines of each speed threshold. E.g

Min speed
Endurance speed
Etc

A

First vertical line: Min speed
2nd: best endurance
3rd: best rate
4th: best range
5th: max airspeed

178
Q

Most efficient angle of attack for most efficiency

A

4 degrees

179
Q

Most efficient angle of attack for most efficiency

A

4 degrees

180
Q

Considering the weight of an aircraft, a lighter aircraft will require (less/more) power to fly than a heavy aircraft, and hence a (lower/higher) fuel flow, (decreased/increased) range and (decreased/increased) endurance

A

Less
Lower
Increased
Increased

181
Q

Why use Best Rate of climb? (Vy)

A

To achieve the greatest height attained over time

182
Q

Why use Best Angle (during climb)? (Vx)

A

Best height attained for a given horizontal distance (used for obstacle clearance)

183
Q

Effect of weight in a climb

A

Automatic increase in rearward component of weight during a climb.

To maintain airspeed, the angle of climb needs to be decreased; therefore there will be a reduction in the rate of climb

184
Q

Effect of altitude on climbing

A

As we climb, our engine loses power and therefore loses its excess power, which is what our aircraft climbs on.

Therefore, a decrease in climb performance occurs as we increase altitude.

185
Q

Rate One Turn Formula

A

= (TAS / 10) + 7

Gives the angle of bank

186
Q

Advantages of a fine pitch propeller

A

Short takeoff run
Good rate of climb

187
Q

Arranges of a coarse pitch prop

A

Relatively good cruising speed
Low fuel consumption
Less engine wear

188
Q

What are the characteristics of a variable pitch prop?

A

Blade angle can be altered
Has definite settings
Usually fitted to higher powered engines to better utilise the power available and increase efficiency
Can only be adjusted on the ground

189
Q

What are the characteristics of a variable pitch prop?

A

Blade angle can be altered
Has definite settings
Usually fitted to higher powered engines to better utilise the power available and increase efficiency
Can only be adjusted on the ground

PPL aircraft tech (1 decks)

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