aircraft system M3 Flashcards
brings in air from the outside, mixes it with fuel, and
delivers the fuel-air mixture to the cylinder where combustion occurs.
induction system
Outside air enters the induction system through an intake port on the front of
the _________
engine cowling
This port normally contains an air filter that inhibits the
entry of dust and other foreign object
intake port
The engine used in light aircraft is usually equipped with either a ______ or a ________
carburetor, fuel-injection system
two types of induction systems that are commonly used in small aircraft engines.
carburetor, fuel injection system
It mixes the fuel and air in the carburetor before this
the mixture enters the intake manifold.
carburetor system
It mixes the fuel and air immediately before entry into
each cylinder or injects fuel directly into each cylinder.
the fuel injection system
It is responsible for bringing together and mixing the air and fuel.
carburetor
Aircraft carburetors are separated into two categories:
float-type carburetor and pressure-type carburetor
It is complete with idling, accelerating, mixture control, idle
cutoff, and power enrichment systems
float-type carburetor
the most common of the two carburetor types
float-type carburetor
are usually not found on small aircraft.
pressure-type carburetor
In the operation of the float-type carburetor system, the outside air first ____________, usually located at an air intake in the front part of the
engine cowling.
the outside air first flows through an air filter
a narrow throat in the carburetor.
venturi
Process of the float-type carburetor system
In the operation of the float-type carburetor system, the outside air first flows
through an air filter, usually located at an air intake in the front part of the
engine cowling.
This filtered air flows into the carburetor and through a venturi, a narrow
throat in the carburetor.
The fuel-air mixture is then drawn through the intake manifold and into the
combustion chambers where it is ignited.
Acquires its name from a float that rests on fuel within the float chamber.
float-type carburetor
READ 3 TIMES
A needle attached to the float opens and closes an opening at the bottom of the carburetor bowl.
READ 3 TIMES
A needle attached to the float opens and closes an opening at the bottom of the carburetor bowl.
This meters the amount of fuel entering the carburetor, depending upon
the position of the float, which is controlled by the level of fuel in the float
chamber.
needle attached to the float
When the level of the fuel forces the float to rise,___________closes the
fuel opening and shuts off the fuel flow to the carburetor.
the needle valve closes
• A needle attached to the float opens and closes an opening at the bottom of
the carburetor bowl.
• This meters the amount of fuel entering the carburetor, depending upon
the position of the float, which is controlled by the level of fuel in the float
chamber.
• When the level of the fuel forces the float to rise, the needle valve closes the
fuel opening and shuts off the fuel flow to the carburetor
float type carburator
It opens again when the engine requires additional fuel.
the needle valve: fuel type carburetor
The flow of the fuel-air mixture to the combustion chambers is regulated by ____
the throttle valve
the throttle valve is controlled by the ______ in the flight deck.
throttle
The float-type carburetor distinct disadvantages:
- they do not function well during abrupt maneuvers.
- the discharge of fuel at low pressure leads to incomplete vaporization and difficulty in discharging fuel into some types of supercharged systems.
- The chief dis advantage of the float-type carburetor, however, is its icing tendency
It discharges fuel into the airstream at a pressure well above atmospheric
pressure.
pressure- type carburetor
PRESSURE-TYPE CARBURETOR/ READ
This results in better vaporization and permits the discharge of fuel into the
airstream on the engine side of the throttle valve.
PRESSURE-TYPE CARBURETOR/ READ
This results in better vaporization and permits the discharge of fuel into the air stream on the engine side of the throttle valve.
PRESSURE-TYPE CARBURETOR/ READ
With the discharge nozzle in this position fuel vaporization takes place after the air has passed through the throttle valve and at a point where the drop in temperature is offset by heat from the engine. Thus, the danger of fuel vaporization icing is practically eliminated.
PRESSURE-TYPE CARBURETOR/ READ
With the discharge nozzle in this position fuel vaporization takes place after the air has passed through the throttle valve and at a point where the drop in temperature is offset by heat from the engine. Thus, the danger of fuel vaporization icing is practically eliminated.
The ratio of fuel-to-air that enters the engine manifold is termed
the ______ and is controlled via a lever in the cockpit.
mixture
mixture is controlled via a _____
in the cockpit.
lever
Mixture levers are almost
always painted___ in color and are
usually placed to the ____t of the throttle
lever.
red, right
The volume of the air-fuel mixture entering the intake manifold and the ratio of air-to-fuel in this mixture is controlled by the ______ and the ____ respectively.
throttle, mixture control levers
is incorporated into the carburetor to allow the engine to idle.
idle passage
This is a passageway which bypasses the venturi and provides a path for the fuel to flow directly from the float chamber to the low-pressure side of the throttle valve
idle passage
occurs due to the effect of fuel vaporization and the decrease in air pressure in the venturi, which causes a sharp temperature drop in the carburetor.
carburetor ice
It forms when the air passing through the carburetor venturi
mixes with vaporized fuel causing a large temperature drop within the
carburetor.
carburetor ice
The moisture in the air can form ice, restricting the air and fuel
flow to the engine and resulting in a partial or total loss of engine power.
carburetor icing
is an anti-icing system that preheats the air before it reaches the carburetor and is intended to keep the fuel-air mixture above freezing to prevent the formation of carburetor ice.
carburetor heat
It can be used to melt ice that has already formed in the carburetor if the accumulation is not too great. Using it as a preventative measure is the better option.
carburetor heat
should be checked during the engine run-up
carburetor heat
It is imperative for a pilot to recognize carburetor ice when it forms during
flight to prevent a __________. These symptoms
may sometimes be accompanied by __________
loss in power, altitude, and/or airspeed; vibration or engine roughness.
The use of carburetor heat causes a _______ in engine power, sometimes up
to 15 percent, because the heated air is ___ dense than the outside air that
had been entering the engine. This enriches the mixture
decrease, less
UTILIZING CARB HEAT DOES NOT COME WITHOUT
A COUPLE OF CONSIDERATIONS, THOUGH:
Since that “heated” air entering the carburetor is much warmer and less
dense, your engine now acts as though it’s at a higher altitude because
warmer air is less dense. There will be a ______ associated with the
introduction of carb heat.
slight power loss
Carb heart will __________, so additional engine leaning may
be needed as appropriate.
richen the fuel/air mixture
READ!
UTILIZING CARB HEAT DOES NOT COME WITHOUT
A COUPLE OF CONSIDERATIONS, THOUGH:
The air is not flowing through the air filter which is typically positioned just
before the air enters the carburetor. The carb heat air is usually unfiltered.
UTILIZING CARB HEAT DOES NOT COME WITHOUT
A COUPLE OF CONSIDERATIONS, THOUGH:
• Since that “heated” air entering the carburetor is much warmer and less
dense, your engine now acts as though it’s at a higher altitude because
warmer air is less dense. There will be a slight power loss associated with the
introduction of carb heat.
• Carb heart will richen the fuel/air mixture, so additional engine leaning may
be needed as appropriate.
• The air is not flowing through the air filter which is typically positioned just
before the air enters the carburetor. The carb heat air is usually unfiltered.
READ!
UTILIZING CARB HEAT DOES NOT COME WITHOUT
A COUPLE OF CONSIDERATIONS, THOUGH:
The air is not flowing through the air filter which is typically positioned just
before the air enters the carburetor. The carb heat air is usually unfiltered.
UTILIZING CARB HEAT DOES NOT COME WITHOUT
A COUPLE OF CONSIDERATIONS, THOUGH:
• Since that “heated” air entering the carburetor is much warmer and less
dense, your engine now acts as though it’s at a higher altitude because
warmer air is less dense. There will be a slight power loss associated with the
introduction of carb heat.
• Carb heart will richen the fuel/air mixture, so additional engine leaning may
be needed as appropriate.
• The air is not flowing through the air filter which is typically positioned just
before the air enters the carburetor. The carb heat air is usually unfiltered.
READ Since the use of carburetor heat tends to reduce the output of the engine and to increase the operating temperature, carburetor heat should not be used when full power is required (as during takeoff) or during normal engine the operation, except to check for the presence of, or to remove, carburetor ice.
CARBURETOR HEAT/ READ AGAIN • Since the use of carburetor heat tends to reduce the output of the engine and to increase the operating temperature, carburetor heat should not be used when full power is required (as during takeoff) or during normal engine the operation, except to check for the presence of, or to remove, carburetor ice.
Most aircraft are also equipped with an _____ (OAT)
gauge calibrated in both degrees Celsius and Fahrenheit.
outside air temperature
It provides the outside or ambient air temperature for calculating true airspeed is useful in detecting potential icing conditions.
air temperature (OAT)
In a ________, the fuel is injected directly into the cylinders, or just
ahead of the intake valve
fuel injection system
The air intake for the ___________ is similar to that used in a
carburetor system, with an alternate air source located within the engine
cowling.
fuel injection system
this system has many advantages over a conventional carburetor
system. There is less danger of induction system icing since the drop in
temperature due to fuel vaporization takes place in or near the cylinder.
The fuel-injection system
fuel injected components (6)
- Engine-driven fuel pump
- Fuel-air control unit
- Fuel manifold (fuel distributor)
- Discharge nozzles
- Auxiliary fuel pump
- Fuel pressure/flow indicators.
It provides fuel under pressure from the fuel tank to the fuel-air control unit.
Engine-driven fuel pump
This control unit, which essentially replaces the carburetor, meters fuel based on the
mixture control setting and sends it to the fuel manifold valve at a rate controlled
by the throttle
fuel control unit
After reaching the fuel manifold valve, the fuel is distributed to the individual _________. They are located in each cylinder head, and inject the fuel-air mixture directly into each cylinder intake port.
fuel discharge nozzles
It provides fuel under pressure to the fuel-air control unit for engine starting and/or emergency use.
auxiliary fuel pump
indicates the pressure of the fuel entering the system.
fuel pressure indicators
advantages of fuel injected (6)
ADVANTAGES : • Reduction in evaporative icing • Better fuel flow • Faster throttle response • Precise control of mixture • Better fuel distribution • Easier cold weather starts
disadvantages of fuel injected (3)
DISADVANTAGES : • Difficulty in starting a hot engine • Vapor locks during ground operations on hot days • Problems associated with restarting an engine that quits because of fuel starvation
THE DIFFERENCE BETWEEN CARBURETOR AND FUEL INJECTED IN THE OPERATION OF AIRCRAFT: STARTING
In carbureted engines, the fuel/air mixture meets in the carburetor. The mixture then goes to each cylinder through the air intake. Carbureted engines undoubtedly take less talent to get started.
In the fuel-injected engine, the fuel and air do not mix until they reach the cylinder. Since fuel injection systems shoot fuel directly into the cylinders, they are easier to flood
(too much fuel) when starting. For this reason, starting procedures for fuel-injected engines vary a good bit depending on the aircraft/engine combination.
To increase an engine’s horsepower, manufacturers have developed forced
induction systems. They both compress the intake air to increase its density, the key difference lies in the power supply. (2)
supercharger and turbosupercharger systems
To increase an engine’s horsepower, manufacturers have developed forced
induction systems. They both compress the intake air to increase its density, the key difference lies in the power supply. (2)
supercharger and turbosupercharger systems
an engine-driven air pump or compressor that provides compressed air to the engine to provide additional pressure to the induction air so that the engine can produce additional power.
supercharger
It increases manifold pressure and forces the fuel-air mixture into the
cylinders. Higher manifold pressure increases the density of the fuel-air
mixture and increases the power an engine can produce.
supercharger
THE DIFFERENCE BETWEEN CARBURETOR AND FUEL INJECTED IN THE OPERATION OF AIRCRAFT: CRUISING (read and understand)
Though they are easier to start, carbureted engines are less efficient during
flight. Since the fuel/air mixture in carbureted systems meet at the
carburetor, the mixture is less precise for each cylinder. Fuel injectors are
calibrated to force the same amount of fuel into each cylinder. Because of
their precision, most fuel injection systems also permit monitoring of each
cylinder’s EGT (Exhaust Gas Temperature). EGT probes on each cylinder
allow the pilot to create the ideal engine performance; saving fuel, as well as
reducing wear on the engine. For these reasons, as well as many others, fuel
injected engines are standard on most new aircraft.
Carbureted systems are simple: fewer parts, less complexity, less
maintenance. In fact, our carbureted Cessnas do not need fuel pumps
since the fuel tanks are high (in the wings ) and push the fuel all the way to
the carburetor. One thing carbureted engines do need is carb heat. When
activated, carb heat allows air to flow around the exhaust (to heat up) and
then into the carburetor - bypassing the induction filter. The hot air
melts/prevents ice buildup around the throttle valve. Fuel-injected engines
do not need carb heat, but they do need electric fuel pumps as a starting
flow, as well as a backup for the engine-driven fuel pump.
Carbureted systems are simple: fewer parts, less complexity, less
maintenance. In fact, our carbureted Cessnas do not need fuel pumps
since the fuel tanks are high (in the wings ) and push the fuel all the way to
the carburetor. One thing carbureted engines do need is carb heat. When
activated, carb heat allows air to flow around the exhaust (to heat up) and
then into the carburetor - bypassing the induction filter. The hot air
melts/prevents ice buildup around the throttle valve. Fuel-injected engines
do not need carb heat, but they do need electric fuel pumps as a starting
flow, as well as a backup for the engine-driven fuel pump
The most efficient method of increasing horsepower in an engine is by using a _________
turbosupercharger or turbocharger
Installed on an engine, this booster uses the engine’s exhaust gases to drive an
air compressor to increase the pressure of the air going into the engine
through the carburetor or fuel injection system to boost power at higher
altitude
turbocharger
