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WorksheetsCPL Acft Tech - Carburation
Total questions: 20
Worksheet time: 10mins
The job of a carburetor is to.... (select all of the correct answers)
mix the fuel and air at the correct ratio
atmomise the fuel
ignite the fuel-air mixture
allow the burnt fuel-air mixture to enter the exhaust
What is one disadvantage peculiar to float type carburetors
airframe icing
fuel flow being disturbed by negative 'g' manoeuvres
prone to vapour locking
injector nozzles are easily blocked
The Chemically Correct Mixture (CCM) ratio of Fuel to AIr is
1:15
15:1
12:1
1:12
Normal working limits for Fuel to Air ratio are
1:9 to 1:18
1:8 to 1:20
1:5 to 1:15
1:12 to 1: 20
The fuel to air ratio for maximum power is found at about
1:12
1:16
1:15
1:9
The fuel to air ratio for best economy is found at about
1:12
1:16
1:15
1:9
What are the conditions most likely to lead to detonation
High power setting and a lean mixture
High power setting and a rich mixture
Low power setting and a lean mixture
Low power setting and a rich mixture
The main fuel outlet of the carburetor is located in
the carburetor heat box inlet
the centre of the carburetor venturi
the intake manifold
the fuel injection manifold
To supply extra fuel during increases in engine power (that is, when the throttle is advanced), what does a carburetor have?
an accelerating system
a power enrichment system
a float valve
a mixture control
TRUE or FALSE
To correctly lean the mixture of an aircraft engine, the mixture control should be moved slowly towards the lean position. As the chemically correct mixture is found, the RPM of a fixed pitch propeller will increase.
True
False
A mixture which is too rich can cause
rough running
detonation
high cylinder head temperatures
engine failure
With a fixed pitch propeller, a symptom of carburetor icing is
a gradual decrease in RPM
a gradual increase in RPM
a gradual decrease in oil temperature
a gradual increase in oil temperature
Impact icing is likely to occur and affect the carburetor when the aircraft is flying through visible moisture and the ambient air temperature is...
near or below 0o Celsius
between 0o and -10o Celsius
between 10o and 25o Celsius
as high as +25o Celsius
Refrigeration icing forms because of
latent heat of evaporation caused by the fuel evaporating
latent heat of evaporation caused by the air evaporating
a decrease in static pressure due to the air accelerating
a decrease in static pressure due to the fuel accelerating
Throttle icing forms because of
latent heat of evaporation caused by the fuel evaporating
latent heat of evaporation caused by the air evaporating
a decrease in static pressure due to the air accelerating
a decrease in static pressure due to the fuel accelerating
The use of carburetor heat should be limited on the ground, particularly on grassy areas, as
it is not filtered
it will cause the engine to stop
it can wear out the heat source
the hot air may cause a fire
When using carburettor heat...
the engine will receive air that is less dense and so the RPM can be expected to decrease
the engine will receive air that is more dense and so the RPM can be expected to decrease
the engine will receive air that is less dense and so the RPM can be expected to increase
the engine will receive air that is more dense and so the RPM can be expected to increase
Whilst flying you correctly identify that your engine has carburetor icing. You apply full carburetor heat. If there has been a large ice build up, what is most likely to happen next?
The engine will run roughly
The engine will stop
Maximum power will be restored
Manifold pressure will increase
Carburetor heat is typically obtained from
inside the exhaust manifold
around the exhaust manifold
an electric heater
a heater driven off the crankshaft
What is required at high manifold pressure and high RPM to avoid detonation and overheating?
Power enrichment system
Impulse coupling
Accelerating system
Idling system
