What speed must an eight-pole ac generator turn to produce 400-Hertz ac?
400 RPM. 1,200 RPM. 6,000 RPM.
What is the possible cause when a turbine engine indicates no change in power setting parameters, but oil temperature is high?
Turbine damage and/or loss of turbine efficiency. High scavenge pump oil flow. Engine main bearing distress.
What type of oil do most engine manufacturers recommend for new reciprocating engine break in?
Straight mineral oil. Semi synthetic oil. Ashless dispersant oil.
In what units are turbine engine tachometers calibrated?
Percent of engine RPM. Percent of engine pressure ratio. Actual engine RPM.
Which of the following should a mechanic consult to determine the maximum amount of cylinder cooling fin that could be removed when cracks are found?
AC 43.13-1A. Engine structure repair manual. Engine manufacturer's service or overhaul manual.
What could cause excessive pressure buildup in the crankcase of a reciprocating engine?
Improper warmup operation. Plugged crankcase breather. An excessive quantity of oil.
What unit in an aircraft engine lubrication system is adjusted to maintain the desired system pressure?
Oil viscosity valve. Oil pump. Oil pressure relief valve.
The economizer system in a float type carburetor,
increases the fuel/air ratio at high power settings. functions only at cruise and idle speeds. keeps the fuel/air ratio constant.
Continued and/or excessive heat and centrifugal force on turbine engine rotor blades is likely to cause,
galling. creep. profile.
The fan rotational speed of a dual axial compressor forward fan engine is the same as the,
low pressure compressor. high pressure compressor. forward turbine wheel.
The primary purpose of a cuff on a propeller is to,
distribute anti icing fluid. increase the flow of cooling air to the engine nacelle. strengthen the propeller.
High cylinder head temperatures are likely to result from,
a very rich mixture at high power settings. fouled spark plugs. a very lean mixture at high power settings.
In order to turn a magneto off, the primary circuit must be,
shorted. opened. grounded.
The fuel flow indicator rotor and needle for a motor impeller and turbine indicating system is driven by,
an electrical signal. direct coupling to the motor shaft. a mechanical gear train.
Which statement is correct regarding a four stroke cycle aircraft engine?
The intake valve closes on the compression stroke. The exhaust valve opens on the exhaust stroke. The intake valve closes on the intake stroke.
One source commonly used for carburetor air heat is,
alternate air heat. turbocharger heated air. exhaust gases.
Turbine nozzle diaphragms located on the upstream side of each turbine wheel, are used in the gas turbine engine to,
decrease the velocity of the heated gases flowing past this point. increase the velocity of the heated gases flowing past this point. direct the flow of gases parallel to the vertical line of the turbine blades.
Which of the following fire detection systems measures temperature rise compared to a reference temperature?
Thermocouple. Thermal switch. Lindberg continuous element.
Compression ratio is the ratio between the,
piston travel on the compression stroke and on the intake stroke. combustion chamber pressure on the combustion stroke and on the exhaust stroke. cylinder volume with piston at bottom dead center and at top dead center.
When the switch is off in a battery ignition system, the primary circuit is,
opened. grounded. shorted.
What operational force tends to increase propeller blade angle?
Centrifugal twisting force. Aerodynamic twisting force. Thrust bending force.
What is the primary purpose of the metal tipping which covers the blade tips and extends along the leading edge of each wood propeller blade?
To increase the longitudinal strength of the blade. To increase the lateral strength of the blade. To prevent impact damage to the tip and leading edge of the blade.
Longitudinal (fore and aft) clearance of constant speed propeller blades or cuffs must be at least 1/2 inch (12.7 mm) between propeller parts and stationary parts of the aircraft. This clearance is with the propeller blades,
feathered or in the most critical pitch configuration. at the lowest pitch angle. at takeoff pitch (maximum thrust) angle.
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.
Propeller blade angle is the angle between the,
relative wind and the rotational plane of the propeller. chord of the blade and the relative wind. chord of the blade and the rotational plane of the propeller.
Hot spots in the combustion section of a turbojet engine are possible indicators of,
faulty igniter plugs. dirty compressor blades. malfunctioning fuel nozzles.
What tool is generally used to measure the crankshaft rotation in degrees?
Prop Protractor. Dial indicator. Timing disk.
(Refer to Figure 5 .) With power applied to the bus bar, what switch changes will allow the ignition exciters test switch to function?
Engine master switch, battery switch, and power lever switch. Engine master switch, start switch, and test switch. Engine master switch and power lever switch.
Upon inspection of the spark plugs in an aircraft engine, the plugs were found caked with a heavy black soot. This indicates,
a rich mixture. worn oil seal rings. a lean mixture.
Which of the following is least likely to occur during operation of an engine equipped with a direct cylinder fuel injection system?
Kickback during start. Afterfiring. Backfiring.
The type of oil pumps most commonly used on turbine engines are classified as,
constant speed. variable displacement. positive displacement.
How is the speed of a constant speed propeller changed in flight?
By advancing or retarding the throttle. By changing the load tension against the flyweights in the governor. By varying the output of the governor booster pump.
Which of the following types of electric motors are commonly used in electric tachometers?
Direct current, series wound motors. Synchronous motors. Direct current, shunt-wound motors.
What should be done initially if a turbine engine catches fire when starting?
Continue starting attempt in order to blow out the fire. Turn off the fuel and continue engine rotation with the starter. Continue engine start rotation and discharge a fire extinguisher into the intake.
The stators in the turbine section of a gas turbine engine,
increase the pressure of the gas flow. decrease the velocity of the gas flow. increase the velocity of the gas flow.
What unit in a tachometer system sends information to the indicator?
The synchronous motor. The two phase ac generator. The three phase ac generator.
How many basic types of circuit breakers are used in powerplant installation electrical systems?
Four. Two. Three.
When installing a magneto on an engine, the,
piston in the No. 1 cylinder must be a prescribed number of degrees after top center on the intake stroke. magneto breaker points must be just closing. piston in the No. 1 cylinder must be a prescribed number of degrees before top center on the compression stroke.
What is the difference between a low tension and a high tension engine ignition system?
A low tension system uses a transformer coil near the spark plugs to boost voltage, while the high tension system voltage is constant from the magneto to the spark plugs. A high tension system is designed for high altitude aircraft, while a low tension system is for low to medium altitude aircraft. A low tension system produces relatively low voltage at the spark plug as compared to a high tension system.
By use of a differential pressure compression tester, it is determined that the No. 3 cylinder of a nine cylinder radial engine will not hold pressure after the crankshaft has been rotated 260° from top dead center compression stroke No. 1 cylinder. How can this indication usually be interpreted?
A normal indication. Exhaust valve blow by. A damaged exhaust valve or insufficient exhaust valve clearance.
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