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