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Aircraft General Knowledge Flashcards

(93 cards)

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1
Q

What are the primary and secondary flight controls?

A

Primary - Elevator, Aileron, Rudder

Secondary - Flaps, Leading Edge Devices, Trim Tabs

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2
Q

How can flight controls be controlled?

A

Direct
Power Asissted (Hydraulics)
Fly-by-Wire

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3
Q

What are the types of stress placed on an airframe?

A

Tension
Compression
Torsion
Shear
Bending

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4
Q

What is meant by Elastic Limit?

A

The limit of distortion at which the structures returns to its original shape and dimensions

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5
Q

What is meant by Yield Point?

A

The point at which deformation becomes permanent

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6
Q

What is meant by Ultimate Load?

A

The load at which failure of the structure occurs

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7
Q

What is meant by Airframe life?

A

The number of cycles/hours the airframce can fly.

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8
Q

Which part of the aircraft structure supports the weight of the aircraft?

A

Wing Spar

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9
Q

What is a monocoque construction?

A

No internal bracing members, only formers and skin. The skin forms an integral part of the stress carrying structure. The skin is the main load carrier.

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10
Q

What is a semi-monocoque construction?

A

Base on monocoque, but makes use of stringers. A light-weoght frame covered by metallic stressed skin which shares the load carriying with the underlying structure.

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11
Q

What is the firewall?

A

The structure separating the engine compartment from the fuselage. Typically made out of stainless steel.

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12
Q

What are the three types of conventional trim?

A

Fixed (Ground Adjustable) Trim
Simple Trim
Spring Loaded Trim

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13
Q

What are the types of fuel tank?

A

Integral
Bladder
Wet Wing

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13
Q

What are fuel tank baffles?

A

Structures that restrict the free movement of fuel inside the fuel tanks. Prevents CoG moving excessively, fuel slamming around and fuel moving away from the pick-up pipe.

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14
Q

Describe Oleo Undercarriage

A

A chamber of gas and oil as a dampening shock absorber. Torque link keeos the wheel pointing in the right direction whilst allowing up and down movement of oleo.

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15
Q

What could happen to aircraft steering when oleo reaches full extension?

A

Typically when the oleo reaches full extension, the nose wheel will self centre and disengage from the rudder pedals.

This could mean more rudder is required during a cross wind takeoff.

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16
Q

What does the shimmy damper do?

A

Prevent nose wheel shimmy.

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17
Q

What can cause nosewheel shimmy?

A

Excessive play in or broken torque connection
Incorrect Tyre Pressure
Unevenly worn Tyres
Shimmy Damper fluid low
Nose Wheel bearings worn

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18
Q

What are ways to cope with nosewheel shimmy?

A

Descrease nosewheel load
Ease off braking
With Caution, when all else fails, full down elevator

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19
Q

How can over and underinflated tyres affect performance?

A

Over Inflated
Bounce on Landing
Excessive wear in the centre
Higher Aquaplaning speed

Under Inflated
Burst/Deflate on Landing
Increased tendency to creep
Excessive wear at the edges
Lower Aquaplaning speed

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20
Q

What is the most common type of aircraft brake?

A

Hydraulic Disc Toe Brakes

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21
Q

What are spats and why must caution be exercised?

A

Spats are wheel/tyre covers. Spats must be clean as any mud/grass can cause friction and reduced performance.

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22
Q

What are the gear limiting speeds?

A

Vlo = Max speed for gear operation
Vle = Max speed with gear extended

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23
Q

What are the properties of good hydraulic fluid?

A

Incompressible
Thermal Stability
Good Lubrication
Low Viscosity
Low Volatility
Non-Corrosive

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24
What are the contents of a basic hydraulic system?
Reservoir Pump Accumulator Selector Valve Actuator T&P Gauges
25
What are the two types of propeller?
Fixed Pitch Variable Pitch
26
Describe the relationship between AoA and airspeed for a fixed pitch propeller
At a low forward speed, the relative AoA is high, which means it is hard work and RPM will be low. At a high forward speed, the relative AoA is low, which means it is easier work and RPM will be high.
27
What is Fine and Coarse Pitch?
Fine Pitch - Low Blade Angle Coarse Pitch - High Blade Angle
28
What happens to a Fixed Pitch Propeller in a climb?
Airspeed reduces, relative airflow angle increases, propeller is harder work, RPM reduces.
29
What is the CSU?
Constant Speed Unit. A mechanism that detects RPM change and adjusts propeller blade AoA to ensure the set RPM is maintained.
30
In what sequence should Power and RPM be changed?
To increase Power Power UP Increase RPM first Increase Throttle Second To reduce Power Throttle BACK Decrease Throttle First Decrease RPM Second
31
What is the square and over-square rule of a Variable Pitch Prop?
Square Rule A generic rule that conserves engine life and safer option. MAP equals RPM. Therefore 2000RPM = 20" MAP Over-square MAP never more than RPM + 4
32
What happens to CSU and Engine during climbs descents on a Variable Pitch Prop?
During a Descent Static Pressure increases MAP will also increase During a Climb Static Pressure decreases MAP will also decrease
33
How should propeller be set during an engine failure?
Fully Coarse to allow the least drag
34
What are the 4 strokes of an otto cycle?
Intake Compression Power Exhaust Suck Squeeze Bang Blow
35
What are the top and bottom positions of the cylinder known as?
Top Dead Centre (TDC) Bottom Dead Centre (BDC)
36
What is the compression ratio?
The ratio between the volume of cylinder at BDC and TDC
37
What is the typical compression ratio of a Lycoming Piston Engine?
7:1
38
Is a higher or lower compression ratio more efficient?
A higher compression ratio is more efficient. However the compression ratio is limited by the type of fuel used.
39
Describe Pre-Ignition
The fuel/air mixture is ignited too early, before TDC. Caused by too low fuel octane, cylinder hotspots, high cylinder pressures. To correct, mixture to full rich and reduce engine power.
40
Describe Detonation
The fuel/air mixture is ignited too quickly and explodes. Caused by too low octane fuel, incorrect engine timing, incorrect fuel/air mixture or labouring engine. To correct, mixture to full rich and reduce engine power.
41
What are the five purposes of an aircraft oil system?
Lubrication Sealing Cooling Cleaning Protection
42
What are the two types of oil?
"Straight" (S) Mineral oil. Typically only used for around 50 hours to wear in an engine. "W" Ashless Dispersant Oil. Prevents corrosion and dissolves certain particles. They must not be mixed.
43
How does oil grade vary with temperature?
Higher grade numbers are thicker oil for a given temperature.
44
What are the two types of Oil System?
Wet Sump Dry Sump
45
Describe a Wet Sump system
Oil collects at the bottom of an engine where it cools before being recirculated by the oil pump
46
Describe a dry sump oil system
A scavenge pump collects oil from the lower parts of the system (small sump) and pumps the oil back to the oil tank, for it to be recirculated. Provides a larger oil supplu for large (typically radial) engines
47
Where is the oil pressure sensor located?
Oil pressure sensor is located on the high pressure side of the oil distribution system. Ie after the oil pump.
48
Is oil pressure after start important?
Yes. Oil pressure should be one of the first guages checkes after engine start. If oil pressure does not rise within 30 seconds, the engine must be shut down immediately.
49
Where is the oil temperature sensor located?
Placed immediately after the oil cooler to monitor the cooled oil temperature.
50
What is the correct order of oil flow for a typical light aircraft piston engine
Pump, Filter, Cooler, Pressure Sensor
51
What are the grades and colours of aviation fuel?
AVGAS 80 - Red AVGAS 100 - Green AVGAS 100LL - Blue Jet A - Colourless/Straw
52
What is MOGAS?
Motor Gasoline, ie car petrol. Only allowed to be used when specified by the manufacturer. It is more flammable and explosive than 100LL.
53
What are the two types of fuel system?
Gravity Fed Pump Fed
54
On a pump fed system, what pumps are there?
Mechanical Pump, driven by the engine. Electric Pump, used as backup and for critical flight phases.
55
What is the ideal ratio of fuel to air?
1:12
56
What are the two different types of fuel air mixer?
Carburettor Injection System
57
How does a Carburettor work?
Carburettors use the venturi effect to to produce a pressure drop that sucks fuel into the airflow from the float chamber via a discharge nozzle.
58
What happens to the carburettor as altitude increases but all else remains the same?
As altitude increases, density decreases. The carb will still allow the same amount of fuel through for a given setting. This results in the air/fuel mixture becoming rich. There will be less efficient burning of the mixture resulting in a reduction in power (RPM) and burn temperature. Therefore, as the aircraft ascends, the mxture must be leaned.
59
What is mixture control Idle Cut-Off?
When the mixture control is operated to fully lean, this cuts ALL fuel off to the discharge nozzle.
60
What are the results of a mixture that is too rich?
The burn is not efficient (Cooler burn) Power (RPM) reduces The engine runs cooler Spark plugs may begin to foul Engine may stop if mixture becomes incombustible
61
What are the results of a mixture that is too lean?
The burn is not efficient (Hotter Burn) Power (RPM) reduces The engine runs hotter The mixture is prone to pre-ignition or detonation Engine damage may result Engine may stop if mixture becomes incombustible
62
What is the approximate air temperature drop inside a carburettor and what is the problem?
Approximate drop of 25-30 degrees C through the carburettor Venturi. Carb Icing is the problem.
63
What is Carb Icing?
Due to the temperature drop through the venturi, water droplets can freeze, forming ice in the venturi. This can restrict the mixture volume to the engine and/or restrict the movement of the butterfly valve (throttle)
64
When is carb icing a concern?
Carb Icing can occur at any OAT when humidity is present. Humidity is the dominant factor. Therefore carb icing is more likely on warm days. It is also most likely to occur at descent power.
65
What are symptoms of carb icing?
A gradually decreasing RPM (Fixed Pitch Prop) A gradually decreasing MAP (Variable Pitch Prop) Rough Running Engine Failure
66
How is carb ice dealt with?
Through carb heat. Intake air is switched to a warm source and the warm air melts the ice.
67
What are the effects of carb heat?
Warm air melts the ice. Water will mix with the air/fuel mixture. The engine may initially run more rough. Once all ice melted and water removed, engine smoothness will be restored. With carb heat providing the engine with less dense hot air, the engine will underperform.
68
What are advantages and disadvantages of Fuel Injection?
Advantages Reduction in evaporative Icing Better fuel flow Faster throttle response Precise control of mixture Better fuel distribution Easier cold weather starts Disadvantages Difficulty in starting a hot engine Vapour locks during ground operations on hot days Problems associated with restarting an engine start stops because of fuel starvation
69
What is the specific gravity of AVGAS?
0.72
70
Describe Spark Plug Fouling
At low RPM or Rich mixture settings, any lead or carbon deposits that form are not burnt off. This causes an intermittent short circuiting of the plug gap, resulting in either a weak or no spark.
71
What are the causes of spark plug fouling?
Long periods of low (idle) engine RPM Operating in dusty environments Failure to lean the mixture at idle in accordance with POH
72
How does the ignition system ensure that it is fail-safe?
It will continue to work without any external electrical power. Only rotary motion is required, meaning the magneto will produce a spark so long as the engine is rotating. Also, if the grounding P-wire breaks the magneto can produce a spark, meaning it is fail-safe.
73
How are magnetos prevented from sparking?
When the magneto switches are off, this connects the P-wire to Earth, meaning the magneto is grounded. The P-wire must be connected. If the P-wire breaks the magneto can produce a spark, meaning it is fail-safe.
74
Which magneto is conventionally the impulse magneto?
The left magneto
75
In magneto "Run-Up" checks, what is being checked?
The maximum RPM drop for each magneto The maximum difference in RPM drop between the two magnetos
76
What are the voltage and capacities of batteries connected in parallel?
The overall system voltage remains the same The capacity of the system is the sum of the battery capacities
77
What are the voltage and capacities of batteries connected in series?
The overall system voltage is the sum of the voltages The capacity of the system is the capacity of one battery
78
How many times can a circuit breaker be reset in flight?
Once Only
79
What caution should be exercised with the starter motor?
Very high current is drawn by the starter motor. Taking a toll on the battery Engine cranking should be limited to 10 seconds to prevent battery/motor overheating Sufficient recovery time between start attempts should be allowed to allow cooling
80
Should the starter warning light be on or off after start?
After start, the starter warning light should be off. If it is on, it signifies the cog has not disengaged from the flywheel and the engine must be shut down immediately to prevent damage.
81
What is the most effective way to cool an engine in flight?
Reduce power, ensure the mixture is rich and increase airspeed.
82
How does the cowling affect cooling?
The engine cowl is designed to form an envelope around the engine to force the air around the cylinders.
83
Which mixture helps engine cooling?
A rich mixture as this burns at a lower temperature.
84
How is a centre-zero ammeter read?
Centred/0 means all electrical power is being supplied by the alternator and the battery is fully charged. Right/Positive means all electrical power is being supplied by the alternator and the battery charging. Left/Negative means the alternator is unable to supply all of the power requirements and battery is being used to compensate.
85
What are the actions to take in the event of an Alternator failure?
Reduce electrical load to bare essentials. One Radio and nav lights if flying at night. Inform ATC Be prepared to use visual navigation Be prepared for Radio Failure and what to do Land as soon as practicable
86
What does low oil pressure and high oil temperature mean?
Oil is probably being lost. The temperature is increasing since the remaining oil is being recirculated quicker, having less time to cool. In addition, because of the higher oil temperature, the oil becomes thinner and hence oil pressure reduces. Land ASAP.
87
What does normal oil pressure but high/low oil temperature mean?
Oil Temperature and Pressure are related. So if one remains the same but the other changes, it is likely a malfunctioning guage, assuming the situation does not change. But exercise caution.
88
What are the two types of fuel guages?
Float Type Capacitance Type
89
At what pitch and bank will an AI typically topple?
Pitch angles greater than 70 degrees Bank angles greater than 110 degrees
90
What does the turn indicator show?
RATE of turn. NOT bank.
91
Is cockpit pressure higher or lower than outside atmospheric pressure?
Cockpit pressure is lower than outside atmospheric pressure in light aircraft.
92

PPL Theory (5 decks)

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