ENGINE FUEL PART 1

Which statement is correct regarding a continuous-flow fuel injection system used on many reciprocating engines?. Fuel is injected directly into each cylinder. Fuel is injected at each cylinder intake port. Two injector nozzles are used in the injector fuel system for various speeds.

Under which of the following conditions would an engine run lean even though there is a normal amount of fuel present?. The use of too high an octane rating fuel. Incomplete fuel vaporization. The carburetor air heater valve in the HOT position.

(Refer to Figure 7.) What is the purpose of the fuel transfer ejectors?. To supply fuel under pressure to the engine-driven pump. To transfer fuel from the boost pump sump to the wing tank. To assist in the transfer of fuel from the main tank to the boost pump sump.

In order to stabilize cams, springs, and linkages within the fuel control, manufacturers generally recommend that all final turbine engine trim adjustments be made in the. increase direction. decrease direction. decrease direction after over-adjustment.

If the idling jet becomes clogged in a float-type carburetor, the. engine operation will not be affected at any RPM. idle mixture becomes richer. engine will not idle.

A fuel pressure relief valve is required on. engine-driven diaphragm-type fuel pumps. engine-driven vane-type fuel pumps. centrifugal fuel boost pumps.

What is the possible cause of an engine running rich at full throttle if it is equipped with a float-type carburetor?. Float level too low. Clogged main air bleed. Clogged atmospheric vent.

What is the relationship between the pressure existing within the throat of a venturi and the velocity of the air passing through the venturi?. There is no direct relationship between the pressure and the velocity. The pressure is directly proportional to the velocity. The pressure is inversely proportional to the velocity.

Which of the following is NOT an input parameter for a turbine engine fuel control unit?. Compressor inlet pressure. Compressor inlet temperature. Ambient humidity.

The purpose of the back-suction mixture control in a float-type carburetor is to adjust the mixture by. regulating the pressure drop at the venturi. regulating the pressure on the fuel in the float chamber. regulating the suction on the mixture from behind the throttle valve.

Fuel crossfeed systems are used in aircraft to. purge the fuel tanks. jettison fuel in an emergency. maintain aircraft stability.

Which method is commonly used to adjust the level of a float in a float-type carburetor?. Lengthening or shortening the float shaft. Add or remove shims under the needle-valve seat. Change the angle of the float arm pivot.

In turbine engines that utilize a pressurization and dump valve, the dump portion of the valve. cuts off fuel flow to the engine fuel manifold and dumps the manifold fuel into the combustor to burn just before the engine shuts down. drains the engine manifold lines to prevent fuel boiling and subsequent deposits in the lines as a result of residual engine heat (at engine shutdown). dumps extra fuel into the engine in order to provide for quick engine acceleration during rapid throttle advancement.

The fuel systems of aircraft certificated in the standard classification must include which of the following?. An engine-driven fuel pump and at least one auxiliary pump per engine. A positive means of shutting off the fuel to all engines. A reserve supply of fuel, available to the engine only after selection by the flightcrew, sufficient to operate the engines at least 30 minutes at METO power.

The active clearance control (ACC) portion of an EEC system aids turbine engine efficiency by. adjusting stator vane position according to operating conditions and power requirements. ensuring turbine blade to engine case clearances are kept to a minimum by controlling case temperatures. automatically adjusting engine speed to maintain a desired EPR.

The purpose of the diaphragm in most vane-type fuel pumps is to. maintain fuel pressure below atmospheric pressure. equalize fuel pressure at all speeds. compensate fuel pressures to altitude changes.

What is the purpose of the carburetor accelerating system?. Supply and regulate the fuel required for engine speeds above idle. Temporarily enrich the mixture when the throttle is suddenly opened. Supply and regulate additional fuel required for engine speeds above cruising.

Which type of pump is commonly used as a fuel pump on reciprocating engines?. Gear. Impeller. Vane.

Float-type carburetors which are equipped with economizers are normally set for. their richest mixture delivery and leaned by means of the economizer system. the economizer system to supplement the main system supply at all engine speeds above idling. their leanest practical mixture delivery at cruising speeds and enriched by means of the economizer system at higher power settings.

What is the purpose of an engine-driven fuel pump bypass valve?. To divert the excess fuel back to the main tank. To prevent a damaged or inoperative pump from blocking the fuel flow of another pump in series with it. To divert the excess fuel from the pressure side of the pump to the inlet side of the pump.

The Federal Aviation Regulations require the fuel flow rate for gravity systems (main and reserve) to be. 125 percent of the takeoff fuel consumption of the engine. 125 percent of the maximum, except takeoff, fuel consumption of the engine. 150 percent of the takeoff fuel consumption of the engine.

A full-authority electronic engine control (EEC) is a system that receives all the necessary data for engine operation and. adjusts a standard hydromechanical fuel control unit to obtain the most effective engine operation. develops the commands to various actuators to control engine parameters. controls engine operation according to ambient temperature, pressure, and humidity.

The economizer system of a float-type carburetor performs which of the following functions?. It supplies and regulates the fuel required for all engine speeds. It supplies and regulates the additional fuel required for all engine speeds above cruising. It regulates the fuel required for all engine speeds and all altitudes.

What carburetor component limits the maximum airflow into the engine at full throttle?. Throttle valve.. Venturi. Main metering jet.

The function of the altitude compensating, or aneroid valve used with the Teledyne-Continental fuel injection system on many turbocharged engines is to. prevent an overly rich mixture during sudden acceleration. prevent detonation at high altitudes. provide a means of enriching the mixture during sudden acceleration.

What causes the fuel divider valve to open in a turbine engine duplex fuel nozzle?. Fuel pressure. Bleed air after the engine reaches idle RPM. An electrically operated solenoid.

When trimming a turbine engine, the fuel control is adjusted to. produce as much power as the engine is capable of producing. set idle RPM and maximum speed or EPR. allow the engine to produce maximum RPM regard to power output.

During engine operation, if carburetor heat is applied, it will. increase fuel/air ratio. increase engine RPM. decrease the air density to the carburetor.

Fuel pump relief valves designed to compensate for atmospheric pressure variations are known as. compensated-flow valves. pressurized-relief valves. balanced-type relief valves.

At what engine speed does the main metering jet actually function as a metering jet in a float-type carburetor?. All RPM's. Cruising RPM only. All RPM's above idle range.

Prior to performing engine trimming, the aviation mechanic should. call the control tower to obtain current sea level barometric pressure and temperature. observe the reading on the aircraft outside air temperature (OAT) gauge. obtain a true temperature reading comparable to that of the air that enters the engine.

Which of the following statements concerning a centrifugal-type fuel boost pump located in a fuel supply tank is NOT true?. Air and fuel vapors do not pass through a centrifugal-type pump. Fuel can be drawn through the impeller section of the pump when it is not in operation. The centrifugal-type pump is classified as a positive displacement pump.

When air passes through the venturi of a carburetor, what three changes occur?. Velocity increases, temperature increases, and pressure decreases. Velocity increases, temperature decreases, and pressure decreases. Velocity decreases, temperature increases, and pressure increases.

Select the correct statement concerning the idle system of a conventional float-type carburetor. The low-pressure area created in the throat of the venturi pulls the fuel from the idle passage. Climatic conditions have very little effect on idle mixture requirements. The low pressure between the edges of the throttle valve and the throttle body pulls the fuel from the idle passage.

Where is the main fuel strainer located in the aircraft fuel system?. At the highest point in the fuel system. At the lowest point in the fuel system. At the inlet chamber of the carburetor.