Powerplant Review

Question 1

The general requirements for an aircraft engine include efficiency, reliability, and a low weight-to-horsepower ratio. It also must?
A. have a short time between overhauls, easy access for maintenance, and a wide range of power output at various speeds and altitudes.
B. have good fuel economy, high durability, and be capable of sustained high power output.
C. be compact, efficient, and have a narrow range of power output at a specific speed.

Answer 1

B. have good fuel economy, high durability, and be capable of sustained high power output.

Question 2

The heat engine used predominantly in aviation is the?
A. Radial engine.
B. O-type engine.
C. V-type engine.

Answer 2

B. O-type engine

Question 3

The crankcase of an aircraft engine?
A. houses the valve operating mechanism and the engine cylinders.
B. is lightweight and primarily used as a reservoir for the engine oil.
C. is the foundation of the engine containing crankshaft bearings and cylinder pads

Answer 3

C. is the foundation of the engine containing crankshaft bearings and cylinder pads

Question 4

The cylinders of an aircraft engine are mounted on cylinder pads that are machined onto the crankcase. The common method of attachment of the cylinders to the crankcase is?
A. by studs mounted in threaded holes in the crankcase.
B. by bolts into locking helicoils mounted in the crankcase.
C. by heating the crankcase and cooling the cylinder for an interference fit

Answer 4

A. by studs mounted in threaded holes in the crankcase

Question 5

The crankpin is?
A. used to ensure the crankshaft does not shift in the crankcase.
B. a solid, heavy journal to withstand crankshaft shock loads.
C. hardened by nitriding and is hollow to reduce weight.

Answer 5

C. hardened by nitriding and is hollow to reduce weight.

Question 6

Which statement is correct about radial engine crankshafts?
A. Moveable counterweights serve to reduce the torsional vibrations in an aircraft reciprocating engine.
B. Moveable counterweights serve to reduce the dynamic vibrations in an aircraft reciprocating engine.
C. Moveable counterweights are designed to resonate at the natural frequency of the crankshaft.

Answer 6

B. Moveable counterweights serve to reduce the dynamic vibrations in an aircraft reciprocating engine.

Question 7

What is an advantage of using metallic sodium filled exhaust valves in aircraft reciprocating engines?
A. increased strength and resistance to cracking.
B. reduced valve operating temperature.
C. greater resistance to deterioration at high valve temperature.

Answer 7

B. reduced valve operating temperature.

Question 8

The horsepower developed in the cylinders of a reciprocating engine is known as the?
A. shaft horsepower.
B. indicated horsepower.
C. brake horsepower.

Answer 8

B. indicated horsepower.

Question 9

What are the two functional elements of the centrifugal flow compressor?
A. turbine and compressor
B. bucket and expander
C. impeller and diffuser

Answer 9

C. impeller and diffuser

Question 10

What is the primary advantage of an axial-flow compressor over a centrifugal flow compressor?
A. high frontal area
B. less expensive
C. greater pressure ratio

Answer 10

C. greater pressure ratio

Question 11

On a carburetor without an automatic mixture control, as you ascend to altitude, the mixture will
A. be enriched.
B. be leaned.
C. is not affected.

Answer 11

A. be enriched.

Question 12

Fuel is discharged for idling speeds on a float-type carburetor?
A. from the idle discharge nozzle.
B. in the venturi.
C. through the idle discharge air bleed.

Answer 12

A. from the idle discharge nozzle.

Question 13

The continuous-flow fuel injection system injects fuel into the intake port during which stroke?
A. intake stroke
B. intake and compression stroke
C. all strokes

Answer 13

C. all strokes

Question 14

When a new carburetor is installed on an engine?
A. warm up the engine and adjust the float level.
B. do not adjust the idle mixture setting; this was accomplished on the flow bench.
C. and the engine is warmed up to normal operating temperature, adjust the idle mixture and then the idle speed.

Answer 14

C. and the engine is warmed up to normal operating temperature, adjust the idle mixture and then the idle speed.

Question 15

It is necessary to control acceleration and deceleration rates in turbine engines in order to?
A. prevent blowout or die-out.
B. prevent over-temperature.
C. prevent friction between turbine wheels and the case due to expansion and contraction.

Answer 15

A. prevent blowout or die-out.

Question 16

In a supervisory electronic engine control EEC, any fault in the EEC that adversely affects engine operation?
A. causes redundant back-up systems to take over and continue normal operation.
B. usually degrades performance to the extent that continued operation can cause damage to the engine.
C. causes an immediate reversion to control by the hydromechanical fuel control unit.

Answer 16

C. causes an immediate reversion to control by the hydromechanical fuel control unit.

Question 17

When trimming a turbine engine, the fuel control is adjusted to?
A. produce as much power as the engine is capable of producing.
B. set idle RPM and maximum speed or EPR.
C. allow the engine to produce maximum RPM without regard to power output.

Answer 17

B. set idle RPM and maximum speed or EPR.

Question 18

Hot spots can burn a hole in the combustion section liner on a turbine engine.
This is caused by?
A. a misaligned fuel nozzle resulting in a flame that is not centered in the flame area.
В. insufficient fuel flow to the fuel nozzles.
C. excessive fuel flow to the fuel nozzle which cannot be fully combusted.

Answer 18

A. a misaligned fuel nozzle resulting in a flame that is not centered in the flame area.

Question 19

The use of carburetor heat when it is not needed causes?
A. a very lean mixture.
B. excessive increase in manifold pressure.
C. a decrease in power and possible detonation.

Answer 19

C. a decrease in power and possible detonation.

Question 20

Ground boosted engine manifold pressure is generally considered to be any manifold pressure above?
A. 14.7 inches Hg.
B. 50 inches Hg.
C. 30 inches Hg.

Answer 20

C. 30 inches Hg.

Question 21

An indication of unregulated power changes that result in continuous drift of manifold pressure indication on a turbocharged aircraft engine is known as?
A. overshoot.
B, waste gate fluctuation.
C. bootstrapping.

Answer 21

C. bootstrapping.

Question 22

The purpose of the engine inlet on a turbine engine is to?
A. provide a well-mixed volume of air to the inlet of the compressor.
B. provide a uniform and steady airflow to avoid compressor stall.
C. reduce the speed of the incoming air and direct it at the correct angle toward the compressor blades.

Answer 22

B. provide a uniform and steady airflow to avoid compressor stall.

Question 23

All of the following are recommended markers for reciprocating engine exhaust systems except?
A. Indian ink.
B. lead pencil.
C. white chalk.

Answer 23

B. lead pencil.

Question 24

The purpose of cascade vanes in a thrust reversing system is to?
A. form a solid blocking door in the jet exhaust path.
B. turn the exhaust gases forward just after exiting the exhaust nozzle.
C. turn to a forward direction the fan airstream.

Answer 24

C. turn to a forward direction the fan airstream.

Question 25

Which components make up the magnetic system of a magneto?
A. pole shoes, the pole shoe extensions, and the primary coil
B. primary and Secondary coils
C. rotating magnet, the pole shoes, the pole shoe extensions, and the coil core.

Answer 25

C. rotating magnet, the pole shoes, the pole shoe extensions, and the coil core.

Question 26

What is the approximate position of the rotating magnet in a high-tension magneto when the points first close?
A. full register
B. neutral
C. a few degrees after neutral

Answer 26

A. full register

Question 27

What is the relationship between the distributor and crankshaft speed of aircraft reciprocating engines?
A. The distributor turns at one-half crankshaft speed.
B. The distributor turns at one and one half crankshaft speed.
C. The crankshaft turns at one-half distributor speed.

Answer 27

A. The distributor turns at one-half crankshaft speed.

Question 28

How does the high tension ignition shielding tend to reduce radio interference?
A. Prevents ignition flashover at high altitudes.
B. Reduces voltage drop in the transmission of high-tension current.
C. Receives and grounds high frequency waves coming from the magneto and high-tension ignition leads.

Answer 28

C. Receives and grounds high frequency waves coming from the magneto and high-tension ignition leads.

Question 29

When the switch is off in a magneto ignition system, the primary circuit is?
A. grounded.
B. opened.
C. shorted.

Answer 29

A. grounded.

Question 30

What is the purpose of an impulse coupling with a magneto?
A. to absorb impulse vibrations between the magneto and the engine.
B. to compensate for backlash in the magneto and the engine gears.
C. to produce a momentary high rotational speed of the magneto.

Answer 30

C. to produce a momentary high rotational speed of the magneto.

Question 31

When internally timing a magneto, the breaker points begin to open when?
A. the piston has just past TDC at the end of the compression stroke.
B. the magnet poles are a few degrees beyond the neutral position.
C. the magnet poles are fully aligned with the pole shoes.

Answer 31

B. the magnet poles are a few degrees beyond the neutral position.

Question 32

If the ignition switch is moved from BOTH to either LEFT or RIGHT during an engine ground check, normal operation is usually indicated by a?
A. large drop in RPM.
B. momentary interruption of both ignition systems.
C. slight drop in RPM.

Answer 32

C. slight drop in RPM.

Question 33

Generally, starter brushes should be replaced when they are approximately?
A. one-half their original length.
B. one-third their original length.
C. two-thirds their original length.

Answer 33

A. one-half their original length.

Question 34

Which of the following factors helps determine the proper grade of oil to use in a particular engine?
A. adequate lubrication in various attitudes of flight
B. positive introduction of oil to the bearings
C. operating speeds of bearings

Answer 34

C. operating speeds of bearings

Question 35

The type of oil pump most commonly used on turbine powered engines are classified as?
A. positive displacement.
B. variable displacement.
C. constant speed.

Answer 35

A. positive displacement.

Question 36

During ground operation of an engine, the cowl flaps should be in what position?
A. fully closed
B. fully open
C. opened according to ambient conditions

Answer 36

B. fully open

Question 37

The actual distance a propeller moves forward through the air during one revolution is known as the?
A. effective pitch.
B. geometric pitch
C. relative pitch.

Answer 37

A. effective pitch.

Question 38

How does the aerodynamic twisting force affect operating propeller blades?
A. It tends to turn the blades to a high blade angle.
B. It tends to bend the blades forward.
C. It tends to turn the blades to a low blade angle.

Answer 38

A. It tends to turn the blades to a high blade angle.

Question 39

How do small feathering propellers prevent feathering when the engine is shut down?
A. Latches lock the propeller in low pitch to prevent excess load on the engine at start-up.
B. Oil pressure is held against the pitch change mechanism.
C. Aerodynamic twisting moment prevents feathering.

Answer 39

A. Latches lock the propeller in low pitch to prevent excess load on the engine at start-up.

Question 40

When the centrifugal force acting on the propeller governor flyweights overcomes the tension on the speeder spring, a propeller is in what speed condition?
A. on speed
B. under-speed
C. over-speed

Answer 40

C. over-speed

Question 41

Constant speed non-feathering McCauley, Hartzell, and other propellers of similar design without counterweights increase pitch angle using?
A. oil pressure.
B. spring pressure.
C. centrifugal twisting moment.

Answer 41

A. oil pressure.

Question 42

When lubricating a Hartzell propeller blade with grease, to prevent damage to the blade seals, the service manual may recommend on some models?
A. to pump grease into both zerk fittings for the blade simultaneously.
B. remove the seals prior to greasing and reinstall them afterwards.
C. remove one of the two zerk fittings for the blade and grease the blade through the remaining fitting.

Answer 42

C. remove one of the two zerk fittings for the blade and grease the blade through the remaining fitting.

Question 43

A ground incident that results in propeller sudden stoppage may require a crankshaft run-out inspection. What publication would be used to obtain crankshaft run-out tolerance?
A. current manufacturer’s maintenance instructions
B. type certificate data sheet
C. AC43.13-1A Acceptable Methods, Techniques, and Practices Aircraft Inspection and Repair

Answer 43

A. current manufacturer’s maintenance instructions

Question 44

A QECA (quick-engine-change-assembly) is?
A. used mostly for unscheduled, unexpected engine changes.
B. used whenever the most efficient and expeditious replacement of an aircraft engine is relied upon.
C. must be pre-approved by the administrator or an airframe and powerplant mechanic with inspection authorization.

Answer 44

B. used whenever the most efficient and expeditious replacement of an aircraft engine is relied upon.

Question 45

When mounting a replacement engine, always?
A. install AN bolts of the correct diameter and length while the weight of the engine is still on the engine hoist.
B. secure the engine first with starter bolts, remove the engine hoist and replace the starter bolts with the manufacturer’s specified bolts.
C. Install the manufacturer specified bolts and torque to the manufacturer recommended value.

Answer 45

C. Install the manufacturer specified bolts and torque to the manufacturer recommended value.

Question 46

Which of the following fire detection systems measure temperature rise compared to a reference temperature?
A. thermocouple
B. thermal switch
C. lindberg continuous element

Answer 46

A. thermocouple

Question 47

What is the principle of operation of the continuous loop fire detection system sensor?
A. fuse material which melts at high temperatures
B. core resistance material which prevents current flow at normal temperatures
C. a bimetallic thermo-switch which closes when heated to a high temperature

Answer 47

B. core resistance material which prevents current flow at normal temperatures

Question 48

Which of the following is the safest fire-extinguishing agent to use from a standpoint of toxicity and corrosion hazards?
A. dibromodiflouromethane (Halon 1202)
B. bromochlorodiflouromethane (Halon 1211)
C. bromotriflouromethane (Halon 1301)

Answer 48

C. bromotriflouromethane (Halon 1301)

Question 49

In a fixed fire-extinguishing system, there are two small lines running from the system and exiting overboard. The line exit ports are covered with a blowout type indicator disc. Which of the following statements is true?
A. When the red indicator is missing, it indicates the fire- extinguishing system has been normally discharged
B. When the yellow indicator disc is missing, it indicates the fire-extinguishing system has been normally discharged.
C. When the green indicator disc is missing, it indicates the fire-extinguishing system has had a thermal discharge.

Answer 49

B. When the yellow indicator disc is missing, it indicates the fire-extinguishing system has been normally discharged.

Question 50

During overhaul, reciprocating engine exhaust valves are checked for stretch?
A. with a suitable inside spring caliper.
B. using a manufacturer’s contour or radius gauge or by the stem diameter just behind the head.
C. by placing on a surface plate and measuring its length with a height gauge.

Answer 50

B. using a manufacturer’s contour or radius gauge or by the stem diameter just behind the head.