ASA Powerplant Oral Study Guide All

ASA Powerplant Oral Study Guide (All Questions) Latest Update - Actual Exam 260 Questions and 100% Verified Correct Answers Guaranteed A+

At what point in a turbine engine is the temperature the highest? - CORRECT

ANSWER: At the inlet to the high-pressure turbine.

At what speed does the camshaft turn, relative to the crankshaft speed in a horizontally

opposed engine? - CORRECT ANSWER: The camshaft turns at one half of the

crankshaft speed.

Can a thermal switch-type fire detection system indicate a general overheat condition? -

CORRECT ANSWER: No, this is a spot-type fire detection system, and it cannot

indicate an overheat indication.

Can a thermocouple-type fire detection system indicate a general overheat condition? -

CORRECT ANSWER: No, this is a rate-of-temperature-rise-type of system, and it

cannot indicate a general overheat condition.

Do the counterweights on a propeller tend to move the blades toward high pitch or

toward low pitch? - CORRECT ANSWER: Toward high pitch.

Does a break in a continuous-loop fire detection system keep the system from detecting a fire? - CORRECT ANSWER: No, the unit will show a fault when it is tested, but it will still warn of a fire.

Does a series-wound DC motor have a high or a low starting torque? - CORRECT

ANSWER: A high starting torque.

Does centrifugal twisting moment on a propeller blade tend to move the blades toward

high pitch or toward low pitch? - CORRECT ANSWER: Toward low pitch.

Does the application of carburetor heat cause the fuel-air mixture to become richer or to

become leaner? - CORRECT ANSWER: Heated air causes the fuel-air mixture to

become richer.

Does the fuel-air mixture provided by a float carburetor become richer or leaner as the aircraft goes up in altitude? - CORRECT ANSWER: If the mixture is not adjusted, it will become richer as the aircraft gains in altitude.

Does the fuel-air mixture provided by a float carburetor become richer or leaner when

carburetor heat is applied? - CORRECT ANSWER: The mixture becomes richer when

carburetor heat is applied. 1 / 3

Does the pressure-type continuous-element fire detector system detect a general overheat condition, as well as a fire? - CORRECT ANSWER: Yes, a high temperature on a small portion of the sensor or a lower temperature over the entire sensor will cause it to release enough gas to close the diaphragm switch and warn of a fire.

Does the tachometer of a geared reciprocating engine indicate the speed of the crank

shaft or of the propeller shaft? - CORRECT ANSWER: The speed of the crankshaft.

How are electrical wires protected where they pass through an area of high

temperature? - CORRECT ANSWER: Wires passing through these areas are insulated

with high temperature insulation, and the wires are enclosed in some type of protective conduit.

How are the turbine inlet guide vanes and the first-stage turbine blades in some turbine

engines cooled? - CORRECT ANSWER: High-pressure compressor bleed air flows

through the hollow guide vanes an hollow turbine blades.

How can a mechanic determine the state of charge of the HRD bottles of fire

extinguishing agent? - CORRECT ANSWER: A pressure gage on the bottle shows the

pressure of the contents of the bottle.

How do some turbine engines prevent ice formation on the inlet guide vanes? - CORRECT ANSWER: Hot compressor bleed air flows through hollow inlet guide vanes.

How does a noise suppressor reduce the amount of noise produced by a turbojet

engine? - CORRECT ANSWER: It breaks up the low-frequency vibrations in the

exhaust stream and converts them into higher frequencies. These high frequencies are dissipated by the air more easily than low frequencies.

How does a power recovery turbine increase the power of a reciprocating engine? - CORRECT ANSWER: Exhaust-driven velocity turbines are coupled through a hydraulic drive to the engine crankshaft. Energy that would normally be lost is used to drive the turbines, and the turbines assist in turning the crankshaft.

How does a torquemeter actually measure the torque produced by an engine? -

CORRECT ANSWER: A torquemeter is actually an oil pressure gage. The pressure it

measures is produced in a torque sensor and is proportional to the amount of strain in the torsional shaft that drives the reduction gears of the turboprop engine.

How does a vibrator-type voltage regulator control the output voltage of a DC

generator? - CORRECT ANSWER: The strength of the magnetic field produced in the

voltage regulator relay is proportional to the generator output voltage. When the voltage rises above the regulated value, the relay pulls the contacts open and inserts a resistor in the generator field circuit. The contacts vibrate open and closed, putting the resistor in and out of the field circuit to control the amount of voltage the generator produces. 2 / 3

How does an engine air inlet vortex destroyer help prevent foreign object damage to the

engine? - CORRECT ANSWER: A high-velocity stream of compressor bleed air is

blown out in front of the engine to break up the vortices that form in front of the engine when it is operating at high power on the ground.

How does metallic sodium in an exhaust valve aid in transferring heat? - CORRECT

ANSWER: The sodium melts when the engine is running, and it sloshes up and down

as the valve operates. The sodium picks up heat from the valve head and carries it into the stem so it can be transferred to the cylinder head and dissipated into the air.

How does the automatic mixture control in a pressure carburetor keep the fuel-air

mixture constant as the aircraft changes altitude? - CORRECT ANSWER: It

automatically, and progressively, bleeds the air between the two sides of the air diaphragm and decreases the air metering force. This leans the mixture as the aircraft goes up in altitude.

How does the exhaust gas temperature of a reciprocating engine tell anything about the

fuel-air mixture being burned by the engine? - CORRECT ANSWER: A stoichiometric

mixture (a mixture in which all of the constituents of the fuel-air mixture are burned) produces the highest exhaust gas temperature. The mixture is adjusted to get the highest EGT, and then it is enriched to place it on the rich side of stoichiometric.

How does the mixture control change the fuel-air mixture ratio on the Teledyne- Continental fuel injection system? - CORRECT ANSWER: When the mixture control is in its Full Rich position, all fuel goes to the manifold valve. When it is in the Idle Cutoff position, all fuel is returned to the pump inlet. Intermediate positions vary the amount of fuel that goes to the engine.

How is a pressure-type continuous-element fire detector system checked for operation?

- CORRECT ANSWER: Low-voltage alternating current is sent through the sheath of

the detector element. This heats the element, and it releases enough gas to close the diaphragm switch.

How is a thermocouple-type fire detection system checked for operation? - CORRECT ANSWER: Current is sent through the heater in the thermal test unit. This heats the thermocouple, which produces enough current to close the sensitive relay. Current through the contacts of the sensitive relay closes the slave relay and turns on the fire warning light.

How is most of the troubleshooting done for a modern APU? - CORRECT ANSWER: By

the fault codes generated by the FADEC.

How is oil temperature controlled in an aircraft reciprocating engine? - CORRECT ANSWER: Hot oil is directed through the core of the oil cooler, but cold oil is directed around the outside of the core so it will not be further cooled.

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