Prepware - Powerplant

What could cause excessive pressure buildup in the crankcase of a reciprocating engine?

Plugged crankcase breather.

Full-floating piston pins are those which allow motion between the pin and

both the piston and the small end of the connecting rod.

Which of these conditions will cause an engine to have an increased tendency to detonate?1. High manifold pressure.2. High intake air temperature.3. Engine overheated.4. Late ignition timing.

1, 2, 3.

What is the purpose of installing two or more springs on each valve in an aircraft engine?

To eliminate valve spring vibration or surging.

Which of the following is a good indication of a malfunctioning fuel nozzle when inspecting the exhaust section of an aircraft turbine engine?

Hotspots on the tail cone.

What is the possible cause when a turbine engine indicates no change in power setting parameters, but oil temperature is high?

Engine main bearing distress.

The compressor stators in a gas turbine engine act as diffusers to

decrease the velocity of the gas flow.

Compressor stall is caused by

a high angle of attack airflow through the first stages of compression.

The air passing through the combustion chamber of a turbine engine is

used to support combustion and to cool the engine.

Where is the highest gas pressure in a turbojet engine?

In the entrance of the burner section. (Diffuser)

Three types of turbine blades are

impulse, reaction, and impulse-reaction.

Which statement is correct concerning a thermocouple-type temperature indicating instrument system?

It requires no external power source.

(1) Generally, when a turbine engine indicates high EGT for a particular EPR (when there is no significant damage), it means that the engine is out of trim.(2) Some turbine-powered aircraft use RPM as the primary indicator of thrust produced, others use EPR as the primary indicator.Regarding the above statements,

both No. 1 and No. 2 are true.

Why does one type of Fenwal fire detection system use spot detectors wired in parallel between two separate circuits?

So that a single fault may exist in the system without sounding a false alarm.

What is the maximum number of bonding jumper wires that may be attached to one terminal grounded to a flat surface?

Four.

Bonding jumpers should be designed and installed in such a manner that they

provide a low electrical resistance in the ground circuit.

The most effective method of regulating aircraft direct current generator output is to vary, according to the load requirements, the

strength of the stationary field.

What determines the minimum particle size which will be excluded or filtered by a cuno-type (stacked disc, edge filtration) filter?

The spacer thickness.

In order to relieve excessive pump pressure in an engine's internal oil system, most engines are equipped with a

relief valve.

The indication on a thermocouple-type cylinder head temperature indicator is produced by

a current generated by the temperature difference between dissimilar metal hot and cold junctions.

If the oil in the oil cooler core and annular jacket becomes congealed, what unit prevents damage to the cooler?

Surge protection valve.

Upon what quality or characteristic of a lubricating oil is its viscosity index based?

Its rate of change in viscosity with temperature change.

Oil accumulation in the cylinders of an inverted in-line engine and in the lower cylinders of a radial engine is normally reduced or prevented by

extended cylinder skirts.

(1) Fuel may be used to cool oil in gas turbine engines.(2) Ram air may be used to cool oil in gas turbine engines.Regarding the above statements,

both No. 1 and No. 2 are true.

The term 'reach,' as applied to spark plug design and/or type, indicates the

linear distance from the shell gasket seat to the end of the threads on the shell skirt.

In a four-stroke cycle aircraft engine, when does the ignition event take place?

Before the piston reaches TDC on compression stroke.

In a typical starter-generator system, under which of the following starting circumstances may it be necessary to use the start stop button?

Hung start.

Thermocouples are usually inserted or installed on the

hottest cylinder of the engine.

What is the radial location of the two north poles of a four-pole rotating magnet in a high-tension magneto?

180° apart.

Great caution should be exercised in handling damaged hermetically sealed turbine engine igniter transformer units because

some contain radioactive material.

In a high-tension ignition system, the current in the magneto secondary winding is

induced when the primary circuit is interrupted.

What carburetor component limits the maximum airflow into the engine at full throttle?

Venturi

If a float-type carburetor becomes flooded, the condition is most likely caused by

a leaking needle valve and seat assembly.

Which of the following causes a single diaphragm accelerator pump to discharge fuel?

An increase in manifold pressure that occurs when the throttle valve is opened.

What carburetor component measures the amount of air delivered to the engine?

Venturi

Where is the throttle valve located on a float-type carburetor?

After the main discharge nozzle and venturi.

Where is the engine fuel shutoff valve usually located?

Aft of the firewall.

Maximum power is normally considered to be developed in a reciprocating engine with a fuel/air mixture ratio of approximately

12:1

Which of the following is a function of the differential pressure controller?

It controls all positions of the waste gate except at fully open position.

What is the purpose of the density controller in a turbocharger system?

Limits the maximum manifold pressure that can be produced by the turbocharger at full throttle.

Which of the following would be a factor in the failure of an engine to develop full power at takeoff?

Improper adjustment of carburetor heat valve control linkage.

Generally, a small crack just started in a cylinder baffle

may be stop drilled.

Cracks in cooling fins that do not extend into the cylinder head

may be repaired by removing the affected area and contour filing within limits.

Which of the following is identified as the cambered or curved side of a propeller blade, corresponding to the upper surface of a wing airfoil section?

Blade back.

How is the oil pressure delivery on a hydromatic propeller normally stopped after the blades have reached their full-feathered position?

Electric cutout pressure switch.

When lubricating a Hartzell propeller blade with grease, to prevent damage to the blade seals, the service manual may recommend on some models to

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

Generally, unless otherwise specified by the manufacturer, repairs of nicks, scratches, gouges, etc. on aluminum propeller blades must be made

parallel to the length of the blade.

Proper operation of electric deicing boots on individual propeller blades may best be determined by

feeling the sequence of boot heating and have an assistant observe the loadmeter indications.

An aircraft's propeller system beta range

is used to produce zero or negative thrust.

During the on-speed condition of a propeller, the

centrifugal force of the governor flyweights is equal to the speeder spring force.

Propeller fluid anti-icing systems generally use which of the following?

Isopropyl alcohol.

The holding coil on a hydromatic propeller feathering button switch holds a solenoid relay closed that applies power to the propeller

feathering pump motor.

Which statement pertaining to fuel/air ratios is true?

The mixture ratio which gives the best power is richer than the mixture ratio which gives maximum economy.

Why does the smoothness of operation of an engine increase with a greater number of cylinders?

The power impulses are spaced closer together.

An increase in manifold pressure with a constant RPM will cause the bearing load in an engine to

increase.

A characteristic of dyna-focal engine mounts as applied to aircraft reciprocating engines is that the

shock mounts point toward the engine's center of gravity.

If metallic particles are found in the oil filter during an inspection,

the cause should be identified and corrected before the aircraft is released for flight.

If air is heard coming from the crankcase breather or oil filler during a differential compression check, what is this an indication of?

Piston ring leakage.

What will be the likely result if the piston ring gaps happen to be aligned when performing a differential-pressure compression check on a cylinder?

A worn or defective ring(s) indication.

Which of the following would indicate a general weak-engine condition when operated with a fixed-pitch propeller or test club?

Lower than normal static RPM, full throttle operation.

Which of the following engine servicing operations generally requires engine pre-oiling prior to starting the engine?

Engine installation.

Grinding the valves of a reciprocating engine to a feather edge is likely to result in

preignition and burned valves.

If the exhaust valve of a four-stroke cycle engine is closed and the intake valve is just closed, the piston is on the

compression stroke.

A condition known as 'hot streaking' in turbine engines is caused by

a partially clogged fuel nozzle.

Some high-volume turboprop and turbojet engines are equipped with two-spool or split compressors. When these engines are operated at high altitudes, the

low-pressure rotor will increase in speed as the compressor load decreases in the lower density air.

Anti-icing of jet engine air inlets is commonly accomplished by

engine bleed air ducted through the critical areas.

What is the major function of the turbine assembly in a turbojet engine?

Supplies the power to turn the compressor.

The recurrent ingestion of dust or other fine airborne particulates into a turbine engine can result in

erosion damage to the compressor and turbine sections.

Which statement is true regarding jet engines?

At the higher engine speeds, thrust increases rapidly with small increases in RPM.

Turbine engine components exposed to high temperatures generally may NOT be marked with1. layout dye.2. commercial felt tip marker.3. wax or grease pencil.4. chalk.5. graphite lead pencil.

3 and 5.

What is the function of the inlet guide vane assembly on an axial-flow compressor?

Directs the air into the first stage rotor blades at the proper angle.

The highest heat-to-metal contact in a jet engine is the

turbine inlet guide vanes.

Between each row of rotating blades in a turbine engine compressor, there is a row of stationary blades which act to diffuse the air. These stationary blades are called

stators

In a dual axial-flow compressor, the first stage turbine drives

N(2) compressor.

The airworthiness standards for the issue of type certificates for small airplanes with nine or less passenger seats in the normal, utility, and acrobatic categories may be found in the

Federal Aviation Regulations, Part 23.

Each powerplant installed on an airplane with a Standard Airworthiness Certificate must have been

type certificated

The breaking loose of small pieces of metal from coated surfaces, usually caused by defective plating or excessive loads, is called

flaking.

Engine pressure ratio is the total pressure ratio between the

front of the compressor and the rear of the turbine.

In addition to fuel quantity, a computerized fuel system (CFS) with a totalizer-indicator provides indication of how many of the following?1. Fuel flow rate.2. Fuel used since reset or initial start-up.3. Fuel time remaining at current power setting.4. Fuel temperature.

Three

Which of the following is a primary engine instrument?

Tachometer

The RPM indication of a synchronous ac motor-tachometer is governed by the generator

frequency.

Instruments that measure relatively high fluid pressures, such as oil pressure gauges, are usually what type?

Bourdon tube.

The most satisfactory extinguishing agent for a tailpipe or intake fire is

carbon dioxide.

For fire detection and extinguishing purposes, aircraft powerplant areas are divided into fire zones based on

the volume and smoothness of the airflow through engine compartments.

As the flux density in the field of a dc generator increases and the current flow to the system increases, the

force required to turn the generator increases.

Electric motors are often classified according to the method of connecting the field coils and armature. Aircraft engine starter motors are generally of which type?

Series.

Aircraft electrical wire is manufactured in sizes according to a standard known as

American Wire Gauge (AWG).

What speed must an eight-pole ac generator turn to produce 400-Hertz ac?

6,000 RPM.

Aircraft wire size is determined by using a(n)

wire gauge

Aircraft that operate more than one generator connected to a common electrical system must be provided with

individual generator switches that can be operated from the cockpit during flight.

Which of the following helps determine the proper grade of oil to use in a particular engine?

Operating speeds of bearings.

What will happen to the return oil if the oil line between the scavenger pump and the oil cooler separates?

The return oil will be pumped overboard.

The purpose of a dwell chamber in a turbine engine oil tank is to provide

separation of entrained air from scavenged oil.

What is the purpose of the check valve generally used in a dry sump lubrication system?

To prevent the oil from the supply tank from seeping into the crankcase during inoperative periods.

The primary source of oil contamination in a normally operating reciprocating engine is

combustion deposits due to combustion chamber blow-by and oil migration on the cylinder walls.

The oil used in reciprocating engines has a relatively high viscosity due to

large clearances and high operating temperatures.

What advantage do mineral base lubricants have over vegetable oil base lubricants when used in aircraft engines?

Chemical stability.

Lubricating oils with high viscosity index ratings are oils

in which the viscosity does not vary much with temperature change.

The engine oil temperature regulator is usually located between which of the following on a dry sump reciprocating engine?

The scavenger pump outlet and the oil storage tank.

What would be the result if a magneto breaker point mainspring did not have sufficient tension?

The points will float or bounce.