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WorksheetsPiston pisjai
Total questions: 120
Worksheet time: 10hrs 0mins
Which stroke piston going down?
Intake stroke
Compression stroke
Exhaust stroke
Power
What connect piston and crankshaft ?
Cylinder sleeve
Connecting rod
Piston ring
Crank pin
Which is not valve head configuration
J-head
I-head
L-head
T-head
During which stroke of a four-stroke engine is the exhaust valve open?
Intake
Compression
Power
Exhaust
During which stroke of a four-stroke engine is both valve closed and piston move from TDC to BDC?
Intake
Compression
Power
Exhaust
During which stroke of a four-stroke engine is both valve closed and piston move from BDC to TDC?
Intake
Compression
Power
Exhaust
What is the correct Firing order of 4 cylinder inline
1-2-4-3
3-2-1-4
2-1-3-4
4-3-2-1
What is the correct Firing order of 6 cylinder inline
4-3-2-1-5-6
2-1-3-4-6-5
3-2-1-4-5-6
1-5-3-6-2-4
What is the correct Firing order of 4 cylinder opposed engine
4-3-2-1
2-1-3-4
4-2-3-1
1-3-2-4
What is the correct Firing order of Textron-Lycoming 6 cylinder opposed engine
3-2-1-4-5-6
1-4-5-2-3-6
2-1-3-4-6-5
4-3-2-1-5-6
What is the correct Firing order of Continental motors 6 cylinder opposed engine
2-1-3-4-6-5
3-2-1-4-5-6
1-6-3-2-5-4
4-3-2-1-5-6
What is the correct Firing order of 9 cylinder single row radial engine
1-3-5-7-9-2-4-6-8
3-2-1-4-5-6-7-8-9
2-1-3-4-6-5-8-7-9
4-3-2-1-5-6-7-9-8
What is the purpose of a Test Club Propeller (TCP) in engine testing?
For actual flight to increase aircraft lift
To provide load and cooling airflow during engine test runs
To measure fuel pressure entering the carburetor
To reduce engine friction during idling
Who defined “Horsepower” and established the standard of 1 hp = 550 ft.lb/sec?
Isaac Newton
James Watt
Albert Einstein
Nikola Tesla
What is Indicated Horsepower (IHP)?
The actual power delivered to the propeller after friction losses
The horsepower calculated from the indicated mean effective pressure in the cylinder, without reference to friction losses
The horsepower lost to auxiliary devices such as fuel and oil pumps
The horsepower measured directly at the crankshaft
What is Brake Horsepower (bhp)?
The theoretical power of an engine without considering friction losses
The power lost in overcoming mechanical friction inside the engine
The actual horsepower delivered to the propeller for useful work after subtracting friction losses
The power required to start the engine
The ignition system has 4 main parts. Which one is not included?
The distributor
The spark plug
The ignition harness
The detonator
What are the advantages of the Rich Mixture?
Better fuel cooling action
More power loss
Safeguard against engine damage
A and C are correct
What is the primary function of the connecting rod in a piston engine?
To open and close the intake valves
To carry the forces from the piston to the crankshaft
To act as the combustion chamber
To reduce friction between crankshaft and bearings
In a standard in-line engine, the number of cylinders is generally limited to how many, to ensure effective cooling?
4
6
8
12
Which of the following statements about the crankshaft in piston engines is correct?
The crankshaft converts reciprocating motion of the piston into rotary motion to drive the propeller.
The crankshaft only rotates the camshaft and does not transmit piston forces.
The crankshaft supports the piston directly without the connecting rod.
The crankshaft is only used in radial engines and not in in-line or opposed engines.
Why is the cylinder head of an air-cooled piston engine usually made of aluminium alloy?
To provide maximum strength
To withstand high combustion pressure
To conduct heat efficiently and reduce weight
To ease the assembly with the cylinder barrel
How are the cylinders of a single-row radial engine numbered?
Starting at the bottom left, counter-clockwise
Starting at the top, clockwise
Starting at the bottom right, clockwise
Starting at the top, counter-clockwise
Why do valve need two helical coil spring to operate?
To damp out all the spring surge vibration during engine operation
To reduce the possibility of failure by breakage from heat and metal fatique
Two better than one
Both A and B are correct
What is the advantages of sleeve valve?
It have high volumetric efficiency
Low oil consumption
Unlimited speed operation
Low carbon built-up
What is the angle of exhaust valve seat and face?
30° or 45°
45° or 60°
45° or 90°
60° or 90°
Why valve that have liquid sodium in the stem should not be cut open?
It may contaminate other component
The part may be loose in the engine
It could cause an explosion
It shouldn't be cut open
Which of this poppet valve types are wrong?
Philip type
Tulip type
Semi-tulip type
Mushroom type
What cause valve sticking?
Low cylinder temperature
Dirty oil
Built-up carbon dioxide
Clean air filter
Which of the following is *NOT* one of the four principal requirements for an aircraft piston cylinder assembly?
Lightweight construction to reduce engine mass
Ability to withstand internal pressure and high temperature
Complex manufacturing process for higher precision
Good heat-conducting properties for efficient cooling
Nitriding of a cylinder barrel typically hardens the surface to a depth of about:
0.002 inch
0.020 inch
0.200 inch
2.000 inch
In modern aircraft engines, the *threaded-joint method* is used to join the cylinder barrel to the cylinder head. Which statement best explains why this method is effective?
It requires no heating or cooling during installation.
It allows for frequent disassembly without thread damage.
The interference fit prevents loosening under high temperature operation.
It provides weaker sealing but easier maintenance.
Where is a double throw crankshaft arrangement typically found?
In a single row radial engine
In an in-line six-cylinder engine
In a two-row radial engine, one throw for each row of cylinders
In a single-cylinder in-line engine
What is the main purpose of a dynamic damper fitted to a crankshaft?
To increase the crankshaft’s overall strength
To absorb and balance out vibration forces from power impulses
To provide additional lubrication to journals
To attach the propeller to the crankshaft
Which method is used to reduce vibration in single-throw crankshafts for radial engines?
Adding lubricating grooves
Increasing the thickness of the journals
Using counterweights or dynamic balancing
Using hollow crank pins
What is the main function of crankshaft journals?
To reduce engine noise during operation
To support the crankshaft within the main bearings
To attach connecting rods to the crankshaft
To balance vibrations during rotation
What is the purpose of carburetor ?
Measure the amount of air entering the engine.
Maintain a constant proportion of fuel and air.
Meter into this air the correct amount of atomised liquid gasoline.
All above
Which is not a flow of air through a venturi ?
Side draft
Up draft
Down draft
Diagonal draft
What is the chief disadvantage of the float-type carburetor?
Its response to abrupt manoeuvres
Incomplete vaporisation due to low fuel pressure
Its icing tendency
Difficulty in use with supercharged systems
Why is a separate idling system necessary in a carburetor?
Because the throttle valve cannot control airflow at idle
Because the main discharge nozzle cannot supply fuel when the throttle is closed
Because the float chamber is empty at low RPM
Because the Venturi does not create any airflow at idle
Which of the following statements best explains why evaporation ice is considered the most serious form of carburetor icing?
Because it forms only at freezing point and can block the intake lip quickly
Because it can form at relatively warm temperatures due to combined Venturi and vaporisation cooling effects
Because it only affects turbocharged engines and cannot be removed by carburetor heat
Because it is limited to conditions of snow, sleet, or sub-zero clouds and rarely occurs otherwise
What is the primary reason engine power decreases when carburetor heat is applied?
Warm air has lower density, reducing the mass of air available for combustion
The exhaust manifold absorbs some of the combustion gases
The carburetor flap partially closes, restricting airflow
The fuel-to-air ratio automatically corrects itself, reducing efficiency
How is the air metering force created in the throttle body?
By the action of the throttle stop
By the pressure differential between chamber A and chamber B
By the movement of the idle valve
By the flow of unmetered fuel through the regulator
What is the function of Chamber C in the regulator?
Holds pump delivery pressure
Contains metered fuel pressure
Contains unmetered fuel pressure
Holds impact air pressure
At idle, how does the flow divider distribute fuel?
Fuel pressure is negligible, so no fuel reaches the nozzles
The valve is fully open, allowing unrestricted flow
The valve opens slightly, exposing the V-slot for equal distribution
The flow divider bypasses fuel directly to the fuel pump
What is the purpose of the enrichment jet installed in parallel with the main metering jet?
To improve idle smoothness
To reduce fuel consumption
To increase fuel/air mixture strength for engine cooling at high power
To balance fuel flow among cylinders
What is one of the unique features of the fuel injector pump assembly?
It bypasses fuel directly to the cylinders at idle
It removes vapours from fuel and vents them back to the fuel tank
It eliminates the need for a fuel control unit
It prevents air metering force from fluctuating
What does FADEC stand for?
Full Authority Digital Electronic control.
Full Automatic Dual Engine Controller.
Finalized Analog Engine Control.
Fundamental Authority Digital Electronic Computer.
What to do if both sensors malfunction in dually redundant?
Use power source.
Use synthetic software default values.
Is switch to using a sensor from a non-redundant system.
All of above.
What does the FADEC control?
Fuel supply only
Ignition only
Both fuel mixture and ignition
Cockpit electrical systems
What is the difference between an EEC and FADEC?
EEC has no backup capability
FADEC allows manual override, but EEC does not
Neither allows manual override
EEC allows manual override, but FADEC does not
Which of the following is listed as an advantage of FADEC?
Increases engine weight
Operates without any electrical power
Provides better fuel efficiency
Requires constant pilot mixture adjustment
If the aircraft’s primary electrical system fails, how long can the FADEC battery supply the EEC?
It cannot operate at all
Approximately 2 hours
Until fuel runs out
Only when alternator is running
Which type of magneto is the most widely used today?
Rotating armature type
Rotating magnet type
Stationary magnet type
Dual-magnet type
What happens when the ignition switch is set to the “BOTH” position?
Only one magneto supplies current, and only one spark plug fires in each cylinder.
Both magnetos supply current, but only one spark plug fires in each cylinder.
Both magnetos supply current, and both spark plugs fire in each cylinder.
The ignition system is completely off, and no spark plugs fire.
What do dry, fluffy black deposits on a spark plug usually indicate?
Correct fuel/air mixture at cruise power
Carbon fouling caused by a rich fuel/air mixture
Proper spark plug heat range
Normal combustion deposits
What material is used for the armature core in the high-tension booster coil?
Copper
Aluminum
Soft iron
Stainless steel
Where does the low-tension booster coil get its current from?
Spark plug
Aircraft system
Magneto only
Battery charger
When the pilot operated mag switch is off the primary circuit is.
Full
Opened
Closed
Ground
What is function of capacitor in low tension circuit
Slow down current
Stop voltage
Aids the rapid collapse of the primary’s circuit field
All above
What are 2 types of magneto rotating components
Rotating armature, Rotating magnet
Rotating Field , Rotating magneto
Rotating magneto, Rotating armature
None above
What is the relationship of speed of the distributors and crankshaft speed in the reciprocating engine
The distributor turns at one fourth of crankshaft speed
The distributor turns at one half of crankshaft speed
The distributor turns at one and one fourth of crankshaft speed
The crankshaft turns two times of distributor
When ground checking is being performed the engine’s rpm is
Same
Slightly increase
Slightly drop
Not change
Which of the following actions is NOT recommended during spark plug installation according to the
document
Apply anti-seize compound (e.g., graphite grease) lightly to body threads, avoiding electrodes and washer face.
Use an open-ended spanner for plug fitting to prevent cracking of the insulator.
Ensure the correct type and serviceable sealing washer is fitted before installation.
Confirm that the cylinder head thread is clean before fitting the spark plug.
Why is an automatic timing adjuster used in an engine ignition system?
To automatically maintain the correct air-fuel ratio.
To adjust ignition timing according to engine speed using centrifugal force.
To keep the manifold pressure constant during high-power operation.
To prevent spring and cam wear in the ignition system.
What is the primary function of an air filter installed in an induction system?
Increases the pressure of air entering the engine.
Prevents ice buildup in the air ducts.
Filters out dust and dirt before entering the system.
Cools the air to increase air density.
Which one is advantage of the NACA intake?
It directly increases air pressure into the engine.
It is mounted off the fuselage to reduce the boundary layer.
It is flush with the aircraft's surface to reduce drag.
It is used only in high-speed aircraft.
Why is an induction leak a serious problem in an engine's induction manifold?
It increases system pressure, causing detonation.
It alters the fuel/air mixture and affects CHT temperature.
It causes the fuel system to deliver less fuel than required.
It disrupts oil sump lubrication.
In a liquid-cooled engine, which component controls the flow of coolant through the radiator in order to maintain the minimum coolant temperature while the engine is running?
Water pump
Header tank
Radiator shutters
Thermostat
What was the main benefit of the NACA cowling ?
It completely eliminated the need for cowl flaps.
It reduced aerodynamic drag while also improving engine cooling.
It increased backpressure to improve exhaust performance.
It allowed radial engines to operate without airflow from the propeller.
Why does the exhaust system of an piston engine using a heater muff arrangement require special inspection?
To prevent excessive expansion and rupture of the exhaust pipe.
To prevent excessive heat buildup in the exhaust pipe.
To prevent carbon monoxide leakage into the cockpit.
To ensure even circulation of hot air.
What is one main advantage of superchargers compared to turbochargers?
They use waste air from exhaust gases.
They run at cooler temperatures and have no lag.
They are more fuel-efficient than turbos.
They are lighter and cheaper to install than turbos.
Why does a supercharged engine require significant engine power to operate, and why is it still considered effective?
Because it consumes extra fuel but provides no increase in power.
Because although it uses engine power, the increase in air and fuel leads to higher overall power output.
Because it reduces manifold pressure, resulting in lower efficiency.
Because it operates only at high altitudes where turbos are ineffective.
Why can a significant rise in air temperature be harmful in a supercharged engine?
It decreases air density and increases the chance of detonation.
It increases air density, making the mixture too rich.
It cools the air, reducing combustion efficiency.
It prevents fuel from atomizing properly, causing incomplete vaporization
The two double-lobed impellers rotate in opposite directions and increase the flow of air into the cylinder
The centrifugal supercharger
The Roots supercharger
The vane supercharger
The axial flow supercharger
It consists of a driven inner member with several wedgeshaped fingers extending from it.
Variable datum control
Spring drive
The centrifugal friction clutch
Hydraulic torque converter
Why do turbocharging engines often have intercoolers?
To reduce the velocity of the exhaust gases passing through the turbine.
To increase the density of the compressed air.
To reduce friction in the intake system.
To improve lubrication of the turbocharger bearings.
What is the most important property of lubricating oil in a reciprocating engine?
Its color
Its viscosity
Its smell
Its weight
What is the primary function of ashless dispersant additives in lubricating oils?
To increase the oil's viscosity.
To dissolve and keep harmful metallic ash particles in suspension.
To prevent the oil from freezing at low temperatures.
To make the oil more effective in extreme pressure conditions.
What is the property of a high-viscosity lubricating oil?
Flows very easily like water
Difficult to pour and runs slowly
Has no effect on lubrication
Becomes thinner at cold temperatures
What is the recommended oil for most aero diesel engines?
SAE 30 single-grade oil
10W-40 multigrade synthetic oil
Avgas mixed oil
Automotive gasoline engine oil
What is the color of Avgas 100LL (Low Lead)?
Green
Blue
Purple
Red
What is the main risk of using Mogas with bio-alcohol?
Increases engine power
Improves lubrication
Reduces exhaust gas temperature
Freezes water and causes corrosion
The purpose of lubicating oil in piston engine is
Reduce friction
Provide cooling
Cleanliness
All of above
What supply oil under pressure to engine?
Oil pump
Oil filter
Oil cooler
None of above
What are the two types of oil filters used in aircraft engines, and what materials are they made from?
Fine filter – made of paper element Coarse filter – made of wire mesh element
Fine filter – made of wire mesh element Coarse filter – made of paper element
Both fine and coarse filters are made of the same material, stainless steel alloy
Fine filter – made of cotton gauze Coarse filter – made of foam element
What is the function of the pressure relief valve in the lubrication system?
To maintain oil pressure within specified limits
To increase oil consumption during cruise
To reduce oil temperature at high altitude
To filter out contaminants from the oil
Which factor does NOT affect how much oil an aircraft engine uses?
The type of oil used
Number of cylinders
Engine paint color
Operating temperature of the engine
What materials are oil filter elements usually made of?
Stainless steel only
Porous paper or wire gauze
Titanium mesh
Cotton fabric
Which one is the primary instrument
Exhaust gas temperature
Cylinder head temperature
Engine speed revs per minute
Oil filler cap temperature
Which Hobb meter method is used for commercial operators
When the electric system is on
When oil pressure is running
Sensing vane under a wing or pressure switch attaches at landing gear
When the magnetos are turned off
What is the main advantage of the extremely high pressure in a common-rail system
It reduces the need for a fuel pump
It assures better vaporisation and cleaner combustion
It allows the engine to run without injectors
It eliminates the need for FADEC
Which type of drive coupling use with tachometer generator
Flexible, Splined, Two-pin
Rigid, Splined, Gear
Chain, Pulley, Belt
Magnetic clutch with spring tension
Which method uses a bulb with volatile liquid and a Bourdon tube to measure temperature?
Non-electrical temperature measurement
Bimetallic strip
Gas expansion
Thermocouple junction method
In a DC ratiometer temperature-sensing system, what happens if the sensor circuit is open
The readout is unaffected by supply voltage
The instrument goes to full-scale deflection
The instrument goes to a minimum
The needle fluctuates randomly without settling
Why is carburettor heat applied during engine operation
To enrich the mixture for more power
To prevent or remove ice formation in the carburettor
To cool the intake air for better combustion
To reduce back pressure in the exhaust system
What does the abbreviation CHT stand for
Cylinder Head Temperature
Compressor High Thrust
Cooling Heat Transfer
Cabin Humidity Test
What principle does the thermocouple connected to the indicator use
Resistance change
Electromotive force (EMF) from heat difference
Magnetic induction
Optical reflection
What is the minimum allowable fuel pressure during flight
1 psi
3 psi
5 psi
10 psi
What do absolute pressure instruments measure
Difference between two pressures
Pressure relative to atmospheric pressure
Pressure from zero or vacuum reference
Dynamic pressure only
What is the formula for calculating fuel used
Fuel flow × distance = fuel used
Fuel flow × time = fuel used
Fuel pressure ÷ time = fuel used
Fuel density × RPM = fuel used
What is the principle of an ultrasonic fuel flow sensor
Electromagnetic induction
Pulse of ultrasound measuring time difference
Resistance change due to temperature
Optical beam interruption
When the aircraft is airborne, what additional stress acts on the engine mount
Torsional stress
Exhaust pressure
Fuel flow pressure
Cowling aerodynamic force
What happens to a rod under tension loads
It tends to decrease a bend
It tends to increase a bend
It expands in diameter
It loses elasticity
Ball-bearing control cables are a type of
Hydraulic line
Push-pull cable
Electrical conductor
Teleflex rod
In a helicopter, the engine must be connected to the powertrain through which device so that the
engine can operate independently of the rotor
Governor
Carburetor heat control
Pilot- operated clutch
twist - grip throttle
Before lifting the engine from the mount, what must be done for safety
Let the fuel run out.
Always remove the governor.
Use manual power to lift the engine instead of a hoist.
Check that the sling is in good condition and can support the weight.
What is the primary function of carburetor heat control
Uses heat from the exhaust system to prevent icing of the manifold
Increases air pressure into the carburetor.
Vaporizes fuel more quickly in the fuel tank.
Reduces vibrations caused by the propeller
When is the Magneto Check performed during ground run
Before engine start
At idle only
During run-up
After engine shutdown
What is true about Piston repairs
Not required as often as cylinder repairs most of the wear is between the piston ring and cylinder
Remove more than on the piston skirt.
Piston weigh cannot be decreased easily
Piston can reduced below the specifics minimum.
What is component that commonly cause engine failure
Bearing, connecting rod
Crank case
Cam shaft
Fuel injector nozzle
What is benefits of low power cruise
Low speed
Extended ranges
Good for climb and take off
Increased engine wear
What to avoid during engine shutdown
Over boost
Thermal shock
Over speed
Fuel starvation
The purpose of refacing valve seat?
Improve oil circulation
Faster ignition
Reduce fuel consumption
Tight and proper seal
How often to do valve reconditioning
Every 3 years
Every 2 years
Every overhaul
Every 500 flight hours
When to do a propeller check during ground run-up
Before, after
During
Before, after , and during
Only after engine shutdown
What causes backfiring
Insufficient ignition timing
Properly adjusted fuel mixture
Fuel burns too slowly
More fuel than required that explodes in the intake manifold
What causes after firing
Too rich mixture
Too lean mixture
Fast burning fuel
Incorrect valve timing
When preserving an aircraft engine for more than four weeks but less than one year, which of the
following is NOT a correct procedure
Inject about 6 cm³ of preservative oil into each cylinder through the spark plug holes
Drain the fuel from tanks, lines, and carburetor float chambers
Leave all engine openings (exhaust, intake, vent) uncovered to allow ventilation
Spray external steel parts with engine oil to protect against corrosion
What is the normal procedure for engine preservation
Engine is robust, preservation is not necessary
Drain regular lubricant and fill with corrosion preventive oil before preservation
Regularly move propeller and crankshaft
Store engine without any special treatment
