Revision Flashcards
What are the four stages of the Otto cycle. ( four-stroke cycle)
- Intake, 2. Compression, 3. Power and 4. Exhaust
What is Carburation?
The process of vaporising liquid fuel and mixing with air in
specific proportions
Purpose of the carburation system?
To control the amount of air being drawn into the engine
To dispense the correct quantity of fuel required
To mix this fuel with the incoming air to ensure complete
vaporisation
What are the two systems which relate to the caburation?
Carburettor system and Fuel injection system
What is Detonation
When a gas is compressed it experiences rise in temperature. If the pressure and temperature rise is too great, there will be spontaneous combustion.
What is Pre-ignition
The ignition that occurs before the spark from the plug.
What are two types of Abnormal Combustion?
Detonation and Pre-ignition.
What are the three types of Carburettor icing?
Impact ice, Fuel evaporation ice and Throttle ice.
What are the four types of fuels?
AVGAS 80(red), AVGAS100(green), AVGAS100LL(blue) and Jet A(colourless or straw)
What is the function of a fuel system?
The function of a fuel system is to store fuel and continuously deliver it to the carburettor (or fuel-injection system) in adequate quantities at the proper pressure.
What are the two common types of fuel system?
Gravity-feed fuel system and Pump/Pressure-feed fuel system.
What is a gravity-feed fuel system?
The fuel from the supply tank to the engine is fed under gravity. This system is found commonly on high winged aircraft
What is a Pump/Pressure-feed fuel system?
Pump feed systems where an extra pump helps fuel get to the engine. Usually found on low winged aircraft.
What is the purpose of a lubrication system?
The primary function of the lubrication system is to reduce friction and heat dissipation
What are the lubrication requirements you must follow to be able to fly?
The lubrication system must function properly and you must carry all the certification certificates with you on board the flight.
what are the five functions of lubricating oil?
Lubricating, cooling, cleaning, sealing and protecting.
What the two types of of Lubrication systems?
Wet sump and Dry sump.
What is a dry sump?
An oil reservoir is external to the engine casing, requiring an
extra scavenging pump.
What is a wet sump?
No separate oil reservoir is used but the lowest part of the
crankcase acts as a reservoir for the oil
What are the two indicators to a problems with the lubrication system?
Low oil pressure indication and High oil temperature indication
What does a low oil pressure indicate?
Insufficient oil in the system, leak in the oil tank or oil lines, failure of the oil pump. The oil pressure relief valve is stuck open or faulty gauge – crosscheck with the oil temperature gauge,
What should you do if the oil pressure is low?
Continue monitoring, consider a diversion or land as soon as possible,
particularly it is associated with a rise in oil temp as well.
What does a high oil temperature indicate?
Low oil quantity, Prolonged operation at excessive Cylinder Head Temperature (CHT) and a faulty gauge
What should you do if the oil temperature is high ?
First crosscheck with the oil pressure gauge then reduce power, Increase airspeed, Open cowl flaps (if fitted) and land as soon as possible
What are the electrical systems?
Alternator/Generator, Battery, Ammeter/loadmeter, Master switch, Bus bar, Fuses and/or circuit breakers and Associated electrical wiring
What are the two types of Propellers?
Fixed pitch propeller and Constant speed propeller
When is Fixed pitch propeller most effective?
The optimum angle of attack is achieved only at one RPM
and airspeed combination and compromise between best take-off and cruise
performance
What is a Constant speed propeller?
A system that uses a Constant Speed Unit (CSU) and a
variable pitch propeller and The system automatically maintains the selected RPM
under varying conditions of airspeed and power
What are the main pressure instruments?
Air Speed Indicator (ASI),Altimeter and Vertical Speed Indicator (VSI) .
WHat is the Air Speed Indicator(ASI)?
Shows Indicated Airspeed (IAS) by measuring the dynamic pressure.
What is dynamic pressure?
it is the total (pitot) pressure minus static pressure. It is dues two relative movement, eg Two factors: speed and density.
What is the Altimeter?
Most important instrument for vertical navigation it determines altitude attained.
What are the Altimeter subscale settings?
QNH – Above mean sea level, QFE – Above a specific ground position (radar altimeter) and QNE – ISA value at mean sea level (i.e., 1013.2 hPa)
What is the Vertical Speed Indicator(VSI)?
It Indicates the rate of change of altitude by sensing the rate of change of static pressure
What is Total(Pitot) pressure?
Static pressure + dynamic pressure
What is Static pressure
Total(Pitot) pressure minus dynamic pressure. It is equal in all direction, Not involving relative in movement of the air and decreases with increase in altitude
What are the three Gyro instruments?
Attitude Indicator (AI) / Artificial Horizon (AH), Directional/Heading Indicator and Turn Co-ordinator (TC) / Turn and Slip Indicator (TI)
What does Valve overlap mean?
Both intake and exhaust valves are open around Top-Dead-Centre (TDC) at the start of the induction stroke
In flight, you notice the left-zero ammeter indication has dropped to zero and backlights for avionics have been dimmed. It is most probable that:
The alternator has failed
How can the angle of attack of a fixed pitch propeller be increased the most?
By increasing RPM and decreasing an airspeed
What is the function of a crankshaft?
It is connected to the piston to change the piston’s linear motion to rotation.
One of the disadvantages of fuel injection systems when compared with carburettor systems is?
Difficulty in starting a hot engine
If an aeroplane is cruising at 8,000ft with the mixture correctly leaned, then descends to 1,000ft without making any adjustment to the mixture control, what will be the likely consequence?
Fuel/air mixture will become leaner
The chemically correct fuel/air mixture ratio for an internal combustion engine is
1:15
Pre-ignition is most likely caused by?
Carbon deposits in the cylinder(s)
Maximum pressure within the cylinder in the Otto cycle occurs on which stroke?
Power stroke
What components is the main load bearing on wing construction?
Spar
For a proper internal cooling, reciprocating engines are especially dependent on?
The proper circulation of the lubricating oil
If a circuit breaker pops in flight, you should?
Reset it once only, provided there are no signs of smoke or a burning smell
Which of the following converts mechanical energy from the engine into power for an aeroplane’s electrical system?
Alternator
Detonation is most likely to occur when?
Using an over-leaned mixture at a high power setting.
What is the main purpose of a camshaft in a piston engine?
To apply force to open the intake and exhaust valves.
Impact ice is most likely to form and affect the operation of the carburettor when?
The ambient air temperature is near to, or below 0°C and the aeroplane is flying in cloud, rain or sleet
What is not correct regarding functions of a battery?
It automatically disconnects itself from aircraft electrical system once the alternator becomes self-sustaining
A piston engine with spark plugs installed for an aeroplane must be fuelled with?
AVGAS
Describe a ‘‘Cumulonimbus Cloud (Cb)’?
A heavy, dense cloud with considerable vertical extent in the form of a mountain or huge tower.
Which flaps would increase the lift the most (assume that the same angle of deflection is used)?
Fowler flap
An increase in airspeed from below (i.e., slower than) minimum drag speed to above (i.e., faster than) minimum drag speed during a straight and level flight will cause?
A reduction in induced drag and an increase in parasite drag.
Maximum gliding distance of an aeroplane is obtained when?
The induced and parasite drags are equal
Which of the following instruments provides a direct reading of the bank angle?
Attitude indicator
What changes in aeroplane control must be made to maintain a straight and level flight whilst the airspeed is being increased from stall speed to normal cruising speed?
Gradually decrease the angle of attack to compensate for the increase in lift.
The best way to differentiate between a spin and a spiral descent is that during a spiral descent
The airspeed is continuously and rapidly increasing
Assume that an aeroplane has a fixed tab on the rudder. How would the tab be altered and what is the effect when correcting for a tendency to yaw to the right during a straight and level flight?
Bend the tab to the right, when viewed from behind, to move the rudder to the left.
What is a correct example of to Buys Ballot’s law in the Southern Hemisphere?
f an observer stands with his/her back to the wind the lower pressure will be to the right
What is the major difference between a Turn Coordinator (T/C) and a Turn and Slip Indicator (T/I)?
T/C indicates both yaw and roll but T/I only indicates yaw
When is the sea breeze generally strongest near the coast?
In the early afternoon
In the Southern Hemisphere, when an aircraft climbs out of a dense friction layer, the wind velocity will?
Back and increase in strength
Pitot (or total) pressure is required for the operation of?
The airspeed indicator only
The most common method in which cloud dissipates is through?
Warming of air through subsidence
An Anabatic wind blows?
Upslope and generally occurs during the day
Movement about the lateral axis of an aeroplane is called?
Pitch and it is controlled by the use of elevator
What type of gyro does the Turn Coordinator use?
Rate
An aircraft performing a standard rate (or rate 1) turn will turn through 90 degrees in?
30 seconds
What is the approximate angle of attack at which a stall occurs for cambered aerofoils?
16º AoA
What is an Aerofoil?
An aerofoil is a structure designed to obtain reaction upon its surface from the air through which it moves past such a structure.
( ceoss section of an aircraft wingi)
(extra info) A flat plate is not idea shape because it disturbs the laminar flow , causing vortices and a great increase in drag.
What are the four forces of aerodynamics?
Lift, thrust, drag and weight.
What are the lift augmentation devices?
Improved CL and CLmax, Reducing stall speed (VS vs. VSO) Increased CD and Reduced L/D ratio
What are the types of drag?
Total drag, induced drag, parasite drag, interference, profile drag, form( pressure) and skin fiction drag.
What is Parasite drag?
Drag which is not linked to lift production. eg interference, profile drag, form( pressure) and skin fiction drag.
When is induced drag must effective?
At low air speeds and high angle of attach
When is Parasite drag most present?
At high air speeds
What is the Laminar flow?
layers of air flow smoothly over each other.
What is profile drag?
A mixture of Form drag and skin friction drag
Where is the average location of an aircraft’s mass?
The centre of gravity. (GC)
What are the aircraft principle axis’s?
Lateral, longitudinal and normal axis.
(extra note) each axis is perpendicular to each axis.
Where is the normal axis draw?
From top to bottom of the aeroplane with the Centre of Gravity( GC) in the middle.
Where is the Lateral axis draw from?
It is drawn parallel to the wings
Where is the longitudinal axis drawn from?
It is drawn from tail to nose.
What does the normal axis control?
The rotation of this axis controls Yaw.
What does the Lateral axis control?
The rotation of this axis controls pitch the vertical direction of the aircraft nose.
What does the longitudinal axis control?
The rotation of this axis is roll.
What is a stall?
A condition of flight where the angle of attack exceeds its critical angle of attack, causing the airflow over the upper surface of the aerofoil largely separates and this results in a rapid reduction in Lift and increase in drag
What is air assumed to be?
dry
What is the MSL pressure?
1013hPa
what is MSL temperature?
+15°C
What is the MSL density?
1.225kg/m3
What is the pressure lapse rate?
1hPa/30ft
What is the temperature lapse rate?
2°C/1,000ft
What does ISA stand for?
International Standard Atmosphere
What does MSL stand for?
Mean sea level
What are the four layers of the atmosphere?
Troposphere, Stratosphere, Mesospehere and Thermosphere
Which atomosphere does most aviation occur in?
Troposphere
What is the friction layer?
The layer immediately adjacent to the earth’s surface’ (Approx. 2,000ft ~ 3,000ft)
How much approximately does wind speed drop over land?
1/2 over the land
How much wind speed drop over sea?
2/3 over the sea
What is veer?
Clockwise
change in wind
direction.
What is back?
Anti-clockwise
change in wind
direction
What is Katabatic wind (mountain wind) ?
The mountain cools down, the air becomes heavier so it descends.
What is Anabatic wind( valley wind) ?
The sun warms the mountain, the aire is lighter and ascends.
What are mountain/lee/standing waves?
Mountain Waves is defined as oscillations to the lee side (downwind) of high ground resulting from the disturbance in the horizontal air flow caused by the high ground.
What are thermal (convective) turbulence?
Convective turbulence can be generated in a fluid layer which is heated from below and cooled from above when the temperature difference between the top and the bottom layer is sufficiently large.
What is mircobust?
Mircobust are explosive downdrafts produced in areas of unstable air eg thunderstorms. Less then 3miles wide contain winds upto 140knots. The horizontal outflow can increase both headwinds and tail winds.
What draft is beneath a cumulus (Cu) cloud?
An updraft
What are two types of middle clouds?
Altostratus (As) and altocumulus(Ac)
What are the three types of high clouds?
Cirrostratus (Cs), Cirrus (Ci) and Cirrocumulus (Cc)
Which cloud is Feather like cloud and it is composed entirely of ice crystals?
Cirrus (Ci)
Which cloud is Milky, translucent cloud, entirely composed of ice crystals?
Cirrostratus (Cs)
Which cloud is Cloud banks of small, white
flakes, entirely composed of ice crystals?
Cirrocumulus (Cc)
Which cloud is shaped like layers of bread
rolls, grey cloud bundles, mostly composed of liquid
water?
Altocumulus (Ac)
Which cloud is dense, grey layer cloud,
usually formed from the
thickening and lowering of a cirrostratus cloud?
Altostratus (As)
What are the types of low clouds?
Stratus (St), stratocumulus, Cumulus (Cu) and nimbostratus (Ns)
which cloud is low even layered cloud,
composed of liquid water?
Stratus (St)
Which cloud is heap cloud with flat basis in
the middle or lower level and
the upper part often
resembles a cauliflower?
Cumulus (Cu)
Which cloud is grey or whitish patch or
sheet of cloud, composed of liquid water?
Stratocumulus (Sc)
Which cloud is heavy and dense cloud with considerable vertical extent in the
form of a mountain or huge tower?
Cumulonimbus (Cb)
What does TAF stand for?
Terminal Aerodrome forecast
What does TTF stand for?
Trend Type Forecast
What does METAR stand for?
Meteorological Aerodrome Report
Which is the most important to follow out of TAF,TTF and METAR?
TTF
How do you solve the pressure height?
(1013 – QNH) x 30 + Elevation = PH
How do you solove the density height?
(ISA DEV x120) + PH = Density height
ISA DEV = Outside Air temperature – Temperature @ PH
REMEMBER Temp Laps Rate is 2◦C /1000ft
A pilot is maintaining a
heading of 010°M. If the track he/she
is making is 000°M, what drift is the
aircraft experiencing?
Drift is determined by the
side the tail is on:
Tail LEFT of Track = LEFT Drift,
meaning an aeroplane is experiencing LEFT drift due to the wind from the RIGHT
What does LMT stand for?
Local Mean Time.
360° means how much differences in time?
24hrs
15° means how much differences in time?
1hr
1° means how much differences in time?
4 minutes
15’means how much differences in time?
1 minute
1’means how much differences in time?
4 seconds
Movement about the lateral axis of an aeroplane is called?
Pitch and it is controlled by the use of elevator
