Reciprocating engines Flashcards
The five events of a four stroke cycle engine in the order of their occurrence are
Intake, compression, ignition, power, exhaust
On Small aircraft engines, fuel vaporization may be increased by
circulating the fuel and air misture through passages in the oil sump.
In addition to causing acceleration wear, dust, or sand ingested by a reciprocating engine may also cause
silicon fouling of spark plugs
What method(s) is/are used to provide clean air to the engines of helicopters and turboprop airplanes that have particle (sand and ice) seperators installed
Sharp airflow directional change to take advantage of inertia and/or centrifugal force, and filters or engine inlet screens
If a fire starts in the induction system during the engine starting procedure, what should the operator do?
Continue cranking the engine
The action of a carburetor airscoop is to supply air to the carburetor, but is may also
increase the pressure of the incoming air by ram effect
When will small induction system air leaks have the most noticeable effect on engine operation
at low RPM
Which of the following statements regarding volumetric efficiency of an engine is true?
It is possible to exceed 100 percent volumetric efficiency of some engine by the use of superchargers of the proper type
The purpose of an engine/inlet anti-ice system is primary to
prevent ice formation in engine and/or inlet areas
Anti icing of jet engine air inlets is commonly accomplished by
engine bleed air ducted through the critical areas
What part of an aircraft in flight will begin to accumulate ice before any other
Carburator
Into what part of a reciprocating engine induction system is deicing alcohol normally injected
the airstream ahead of the carburetor
A method commonly used to prevent carburetor icing is to
preheat the intake air
Carburetor icing on an engine equipped with constant speed propeller can be detected by
a decrease in manifold pressure with a constant RPM
Carburetor icing may be eliminated by which of the following methods?
Alcohol spray and heated induction air
Carburetor icing is most servere at
Air tempertures between 30 and 40*F
One source commonly used for carburetor air heat is
exhaust gases
Where would a carburetor air heater be located in a fuel injection system?
none is required
The application of carburetor heat will have which of the following effects
The mixture will become richer
The application of carburetor heat during engine operation will
Decrease the weight of the fuel/air charge
When operating an engine, the application of carburetor heat will have what effect of the fuel/air mixture
Enriching the mixture until the AMC can make a compensation
An increase in manifold pressure when carburetor heat is applied indicates
ice was forming in the carburetor
The use of the carburetor air heater when it is not needed causes
a decrease in power and possibly detonation
If carburetor or induction system icing is not present when carburetor heat is applied with no change in the throttle setting, the
mixture will become richer
When starting an engine equipped with a carburetor air heater, in what position should the heater be placed
cold
A carburetor air pre-heater is not generally used on takeoff unless absolutely necessary because of the
loss of power and possible detonation
Which of the following would be a factor in the failure of an engine to develop full power at takeoff
Improper adjustment of carburetor heat valve control linkage
In an airplane equipped with an alternate air system, if the main air duct air filter becomes blocked or clogged, the
system will automatically allow warm, unfiltered air to be drawn into the engine
During engine operation, if carburetor heat is applied, it will
decrease the air density of the carburetor
Direct mechanical push pull carburetor heat control linkages should normally be adjusted so that the stop located on the diverter valve will be contacted
before stop at the control lever is reached in both HOt and COLD positions
As manifold pressure increases in reciprocating engine, the
density of air in the cylinder increases
If fuel/air ratio is proper and ignition timing is correct, the combustion process should be completed
just after top center at the beginning of the power stroke
When is the fuel/air mixture ignited in a conventional reciprocating engine?
shortly before the piston reaches the top of the compression stroke
Valve overlap is defined as the number of degrees of crankshaft travel
during which both valves are off their seats
On which strokes are both valves on a four-stroke cycle reciprocating aircraft engine open
Exhaust and intake
When does valve overlap occur in the operation of an aircraft reciprocating engine?
At the end of exhaust stroke and the beginning of the intake stroke
Which statement is correct regarding a four stroke cycle aircraft engine
the intake valve closes on the compression stroke
If the intake valve is opened too early in the cycle of operation of a four-stroke cycle engine, it may result in
backfiring into the induction system
If the exhaust valve of a four-stroke cycle engine is closed and the intake valve is just closed, the piston is on the
compression stroke
