Random List Flashcards
What are the four strokes of a four-stroke piston engine?
- Intake, 2. Compression, 3. Power, 4. Exhaust
What is the purpose of the cylinder in a piston engine?
The cylinder houses the piston and provides the space where the air-fuel mixture is compressed and ignited.
What is the function of the piston in a light aircraft engine?
The piston moves within the cylinder, compressing the air-fuel mixture and transferring combustion energy to mechanical motion.
What does the carburettor do in a light aeroplane engine?
The carburettor mixes air and fuel in the correct ratio for combustion and delivers it to the engine.
What are the signs of carburettor icing?
- Drop in RPM (fixed-pitch propeller)
Rough engine operation
Reduced manifold pressure (constant-speed propeller)
What causes carburettor icing?
Carburettor icing occurs when the temperature drop due to fuel vaporization and pressure decrease in the venturi causes water vapor to freeze.
What is the purpose of the carburettor heat?
Carburettor heat is used to prevent or remove ice by directing hot air into the carburettor.
What is the function of the spark plug?
The spark plug ignites the compressed air-fuel mixture in the cylinder, initiating the power stroke.
Name the components of the ignition system.
- Magnetos
Spark plugs
Ignition leads
Switches
What does the crankshaft do?
The crankshaft converts the linear motion of the pistons into rotational motion to drive the propeller.
What is the function of the oil system in a piston engine?
- Lubricates engine components
Cools the engine by reducing friction
Cleans by carrying debris to the oil filter
At what conditions is carburettor icing most likely to occur?
- Temperatures between -5°C and +15°C
High humidity conditions
How can you test for carburettor icing during flight?
Apply carburettor heat; if icing is present, RPM or manifold pressure will initially drop and then increase as the ice melts.
What is the function of the exhaust system in a light aircraft engine?
The exhaust system removes combustion gases from the engine and reduces noise.
What is the function of the throttle?
The throttle controls the amount of air-fuel mixture entering the engine, thus regulating power output.
What is the function of magnetos in an aircraft engine?
Magnetos generate electrical energy for the spark plugs independently of the aircraft’s electrical system.
Why do aircraft engines have dual magnetos?
Dual magnetos provide redundancy for safety and improve engine efficiency and performance by firing two spark plugs per cylinder.
How do you test magnetos during a pre-flight check?
Perform a magneto drop check by switching to ‘Left’ and ‘Right’ magnetos individually and noting the drop in RPM. Ensure the drop is within acceptable limits and consistent between both.
What type of cooling system is commonly used in light aircraft engines?
Most light aircraft engines use an air-cooling system.
How does the air-cooling system work in a light aircraft engine?
Cooling fins around the cylinders dissipate heat, and airflow from the propeller and cowling directs air over these fins to maintain temperature.
What is the function of engine oil in the cooling process?
Engine oil absorbs and carries away heat from engine components to the oil cooler.
What are the consequences of engine overheating?
- Detonation (uncontrolled combustion)
- Pre-ignition
- Reduced engine performance
- Potential engine damage
How can you prevent engine overheating during flight?
- Monitor engine instruments (CHT and oil temperature)
- Use proper climb speeds
- Enrich the fuel mixture
- Increase airflow by opening cowl flaps if equipped
What should you do if carburettor icing is suspected during flight?
- Apply full carburettor heat immediately
- Monitor for changes in RPM or manifold pressure
- Wait for the engine to stabilize before reducing carb heat