Piston Engines Flashcards
You are flying a multi engine propeller aircraft. During the cruise, the critical engine fails. Which configuration creates the most stress on the rudder
Aft CG, skid toward the critical engine
A piston engines compression ratio is the ratio of…
The cylinder volume with the piston at bottom dead centre to the cylinder volume at top dead centre
When excessively leaning the mixture of a piston engine for a better fuel economy, but still on the rich side of the peak EGT, what engine parameters may exceed their normal operating range ?
Cylinder head and exhaust gas temperature
Which of the following statements is correct regarding aircraft engine turbochargers ?
A) The waste-gate is situated in the inlet manifold
B) when the waste gate is fully open the turbocharger is running at full speed.
C) the waste gate actuator is controlled by the waste gate
D) the waste gate diverts exhaust gas to drive the turbine
D) the waste gate diverts exhaust gas to drive the turbine
If detonation occurs in a normally aspirated piston engine during climb- out, the normal corrective action is to…. ?
Retard the throttle
Apart from flight into known icing conditions, the intake system of a diesel engine….
Is never heated because a diesel engine is a injection engine
Dual ignition for a piston engine provides a factor of reliability and…. ?
Improves combustion efficiency
The power output of a diesel engine without a turbo charger is regulated by…?
Fuel flow only
When changing power on piston engines equipped with a constant speed propeller, engine over boost is avoided by…?
Increasing the RPM before increasing the manifold pressure
Consider a variable pitch propeller operating in a low RPM/ High pitch condition. When feather is selected, the
Condition lever ( pitch control) is moved to the feather position and the blades move from high pitch directly to the feather position
The part of a piston engine that transforms reciprocating movement into rotary motion is called the ?
Crankshaft
What is correct with regards to ice accretion in piston engine induction systems ?
Ice accretion affects both fuel injection systems and engines equipped with carburettors
If the ground wire between the magnetos and the ignition switch of a piston engine becomes disconnected the most noticeable result will be that….
The engine cannot be shut down by turning the ignition switch to the OFF position
A piston engine may use a fuel or a different grade than the recommended…?
Provided that the grade is higher
When applying precautionary carburettor heating on a reciprocating engine with a fixed pitch propeller ?
The mixture becomes richer
Consider a variable pitch propeller operating in a high RPM/ low pitch condition. To select reverse thrust, the….?
Power lever is moved to the reverse position and the blades move from low pitch directly to reverse pitch
Cooling air for reciprocating engine is brained by means of…?
Ram air
The purpose of a distributor in an ignition system of a piston engine is to distribute….?
Secondary current to the speaking plugs
The turbocharger waste gate is located in (1)……… and the maximum compressor RPM is achieved when the valve is (2)……..?
(1) turbine
(2) closed
Consider a pistol engine aircraft with a constant speed propeller. Upon reaching cruising altitude when less power is required, engine power is ?
Reduced by lowering the manifold pressure and increasing the blade angle, to decrease RPM
Both gas turbines and piston engines use a cycle made up induction, compression, combustion and exhaust phases. Which of the following statement about a piston engine are correct ?
1) the process in a piston engine is continuous
2) theoretically the combustion occurs at constant volume
1) incorrect
2) correct
The air in a piston engine turbocharger enters the centrifugal compressor at ?
The eye of the impeller and leaves it almost at a tangent to the periphery
Vapour lock is….
A blockage in a fuel feed line caused by a vapour bubble
The operating principle of a float-type carburettors is based on the
Difference in air pressure at the Venturi throat and the air inlet
A piston engine aeroplane with a fixed pitch propeller is flying at normal cruising speed when one magneto fails completely. The initial response of the engine is…
A loss of approximately 100 rpm
Excessive pressure in the cylinders of a piston engine equipped with a constant speed pitch propeller, can be caused by the combination of….
High manifold pressure and low RPM
After start of a piston engine, correct operation of the pitch adjustment system of a constant speed propeller can be confirmed by altering the propeller control lever and checking indications on the…
Tachometer
In the event of an engine failure during flight in a single engine aeroplane not fitted with a feathering system, the blades of a constant speed propeller tend to move…
Towards the smallest blade angle by centrifugal twisting moment and/or spring force
The compression ratio of a piston engine is a ratio of…
Volumes
In s piston engine, applying carburettors heat decreases the (1)……. Of air entering the engine, thereby making the mixture (2)……….
1)Density
2)richer
What is the recommended step to take in case you experience detonation during take off ?
Reduce the throttle
The main purpose of a turbocharger is to….
Maintain power with increasing altitude
In a piston engine, if the ground wire between one of the magnetos and the ignition switch becomes disconnected, the most noticeable result will be that the engine….
Cannot be shut down by turning the switch to the off position
What is the engine control element the pilot may expect on the flight deck of an aircraft with a piston engine controlled by FADEC
Crank Switch
A multi engine piston aircraft both the propellers rotate clockwise as seen from the cockpit. In a go around, one of the engines fails. Which of the following situations will most probably need the pilot to use full rudder deflection ?
LEFT ENGINE FAILURE, LEFT CROSSWIND
What may happen to a piston engine during a continuous climb with a mixture setting fully rich ?
Fouling of spark plugs
The safest method of priming a piston engine for starting is….
Injection of fuel in the cylinder intake ports
What is a correct statement regarding the effect of application of the carb heat
The density of the air entering the carburettor is reduced, which enriches the fuel/air mixture
The primary function of the lubrication system of an air cooled piston engine is to….
Reduce internal friction and provide cooling
The magneto in a piston engine ignition system is switched off by…
Grounding both the primary and secondary circuits
The purpose of the Venturi in a carburettor is to…..
Create the suction necessary to cause fuel to flow through the carburettor main jets
Consider a fuel injection system. Which is the central point from where fuel is distributed to the individual cylinders ?
Manifold pressure
In reference to piston engines, what is meant by the term ‘swept volume ?
The volume displaced by the piston during a single stroke
For a piston engine, pre ignition refers to the condition that may arise when…
The mixture is ignited by abnormal conditions within the cylinder before the spark occurs at the plug
If the manifold pressure gauge of a piston engine shows an increase shortly after carburettor heat is turned on, it indicates that….
Ice was forming in carburettor
When applying carburettor heating what happens to the mixture
The mixture becomes richer
What should the pilot do if a piston engine aircraft experiences detonation during climb out
Decrease manifold pressure
If a manifold pressure gauge consistently registers atmospheric pressure, the cause is probably…….
Leak in pressure gauge line
Complete the following sentence:
High humidity (1)………… piston engine power output, because air density is (2)…………..
(1) decreases
(2) lower
When the pilot moves the mixture lever of a piston engine towards a leaner position the…..
Amount of fuel entering the cylinders is reduced
For take-off, the correct combination of propeller pitch (1), and propeller lever position (2) for a piston engine at brake release is…..
(1) low
(2) forwards
Given the following statements about diesel engines:
1) power is set by the mixture control
2) there is no control
3)the amount of power is determined by the fuel flow only
4)thermal efficiency is higher than that for a petrol engine
5)diesel fuel is more inflammable than petrol
The combination that regroups all of the correct statements is…..
2,3,4
“Vapour lock” is the phenomenon by which…..
Vapour bubbles block the fuel line
What is the purpose of cowl flaps on an aeroplane ?
Air flow across the engine is increased when they are open, which increases cooling efficiency
Which of the following options is a way that FADEC can enhance piston engine operation ?
Automatically altering ignition timing with changes in RPM
What are the actions to unfeather a variable pitch prop…..
Push the propeller lever forward into the normal operating range which results in a blade angle producing thrust.
The pilot of a turbocharged MEP aircraft is climbing with maximum continuous power set until reaching the cruising altitude of 10,000 ft. The pilot levels off and initially maintains power to accelerate to cruise speed. Which of the following actions are required to reduce fuel consumption
Decrease power by reducing manifold pressure and increase the propeller blade angle using the RPM lever.
What option is a desired characteristic for piston engine fuel ?
Good anti knock properties
The blade Angle of a constant speed propeller….
Increases with increasing true air speed
The conditions most likely to produce the highest engine power are….
Cold and dry air at high pressure
The main reason for opening the cowl flaps is to control the…..
C.H.T (CYLINDER HEAD TEMPERATURE)
The function of a diffuser (compensating jet) is to…..
Maintain a constant mixture in a piston engine at low and high power settings
How can FADEC systems on piston engines usually achieve a level of redundancy ?
Each engine is fitted with two FADEC computers
With regard to piston engines, once the engine has started, the ignition system is
Independent of the aircraft electrical system
The camshaft of a piston engine rotates at…..
Half the speed of the crankshaft
One of the primary purposes of a propeller reduction gearing system is to…..
Limit the propeller rotation speed to a value below which efficient operation can be obtained
Which one of the following situations might cause a higher than normal oil pressure indication ?
A stuck oil pressure relief valve.
Assuming the RPM and throttle levers are not altered, when TAS increases the blade angle of a constant speed propeller will
Increase
The power of a piston engine measured by a friction brake is
Brake horse power
What may be controlled by FADEC in a piston engine ?
The mixture ratio and ignition timing
The conditions which can cause detonation in a piston engine are….
High manifold pressure and low rpm
The function of an accelerator pump in the carburettor of a piston engine is to…
Enable proper functioning of a piston engine during throttle advance
In the cockpit of a FADEC controlled single engine piston aircraft with a variable pitch propeller, what engine control levers would you expect to have ?
Power/ throttle lever only
What is a turbocharger used for in a piston aero-engine ?
To compensate for the decrease in MAP with increasing altitude
The ignition system of a running piston engine receives electrical energy from……
Rotating permanent magnets
Inside a reciprocating engine, the connecting rods and the crankshaft convert the (1)…………. Motion of the (2)…….. into (3)………… motion
(1) linear; (2) piston; (3) rotary
There is a gradual loss of oil from the engine lubrication system. Which of the following indications can be expected as a result of this leak
Low/fluctuating oil pressure, high oil temperature
The application of carburettor heating reduces the……
Density of air entering the carburettor, thus enriching the mixture.
What is one of the new features provided by full authority Digital Engine Control (FADEC) in modern piston aircraft engines ?
Ignition timing control
When detonation is recognised in a piston engine, the correct procedure is to…..
Reduce manifold pressure and full enrich the mixture
The use of carburettor heating during take off and climb is discouraged because of the…..
Loss of power and increased risk of detonation
Aircraft fuel tanks should be checked for water…….
Before the first flight of the day because condensation may arise overnight
What is the safest way to prime a piston engine for start-up?
Injecting fuel straight into the inlet valves
An impulse magneto coupling in a piston engine…….
Retards the spark during the engine starting
With regard to a piston engine, the sections of the carburettor where icing would most likely occur are the…..
Venturi and the throttle valve
A FADEC piston engine has two……………to achieve redundancy.
Power supplies and two separate but identical channels
An EGT (exhaust gas temperature) indicator for a piston engine is used to…….
Assist the pilot to set the correct mixture
A piston engine compression ratio is the ratio of the…..
Total volume to the clearance
An intercooler fitted between a supercharger and the inlet manifold will…..
Minimise the risk of detonation
The formula to calculate the total displacement of a multi-cylinder piston engine is…….
Piston area * piston stroke * number of cylinders
The thermal efficiency of a piston engine is about……
30%
