POWERPLANT INSTRUMENTS

A change in engine manifold pressure has a direct effect on the

A. Piston displacement

B. Mean effective cylinder pressure

C. Compression ratio

B. Mean effective cylinder pressure

A red triangle, dot, or diamond mark on an engine instrument face or glass indicates

A. A restricted operating range.

B. The maximum limit for high transients such as starting.

C. The maximum operating limit of all normal operations.

B. The maximum limit for high transients such as starting.

The principle fault in the pressure type fuel flowmeter indicating system, installed on a horizontally opposed continuous-flow fuel injected aircraft reciprocating engine, is that a plugged fuel injection nozzle will cause a

A. Higher than normal fuel flow indication.

B. Normal operation indication.

C. Lower than normal fuel flow indication.

A. Higher than normal fuel flow indication.

The fuel-flow indicator rotor and needle for a motor-impeller and turbine indicating system is driven by

A. Direct coupling to the motor shaft.

B. An electrical signal.

C. A mechanical gear train.

B. An electrical signal.

Why do helicopters require a minimum of two synchronous tachometer systems?

A. One indicates engine RPM and the other tail rotor RPM.

B. One indicates engine RPM and the other main rotor RPM.

C. One indicates main rotor RPM and the other tail rotor RPM.

B. One indicates engine RPM and the other main rotor RPM

Thermocouple leads

A. May be repaired using solderless connectors.

B. May be installed with either lead to either post of the indicator.

C. Are designed for a specific installation and may not be altered.

C. Are designed for a specific installation and may not be altered.

Which of the following instrument discrepancies require replacement of the instrument?

1. Red line missing from the glass

2. Glass cracked

3. Case paint chipped

4. Will not zero out

5. Pointer loose on shaft

6. Mounting screw loose

7. Leaking at line B nut

8. Fogged

A. 2, 3, 7, 8

B. 1, 2, 4, 7

C. 2, 4, 5, 8

C. 2, 4, 5, 8

The fuel flowmeter used with a continuous-fuel injection system installed on an aircraft horizontally opposed reciprocating engines measures the fuel pressure drop across the

A. Fuel nozzles

B. Metering valve

C. Manifold valve

A. Fuel nozzles

Engine pressure ratio is the total pressure ratio between the

A. Front of the compressor and the rear of the turbine.

B. Front of the engine inlet and the aft end of the compressor.

C. Aft end of the compressor and the aft end of the turbine.

A. Front of the compressor and the rear of the turbine.

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

A. It usually contains a balancing circuit in the instrument case to prevent fluctuations of the system voltage from affecting the temperature reading.

B. It is a balanced-type, variable resistor circuit.

C. It requires no external power source.

C. It requires no external power source.

Which of the following instrument conditions is acceptable and does not require immediate correction?

A. Instrument glass fogged

B. Case paint chipped

C. Mounting screws loose

B. Case paint chipped

The engine pressure ratio (ERP) indicator is a direct indication of

A. Pressure ratio between the font and aft end of the compressor.

B. Engine thrust being produced.

C. Ratio of engine RPM to compressor pressure.

B. Engine thrust being produced.

Turbine engine EGT thermocouples are constructed of

A. Iron and constantan

B. Copper and constantan

C. Chromel and alumel

C. Chromel and alumel

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,

A. Both No. 1 and No. 2 are true.

B. Only No. 1 is true.

C. Only No. 2 is true.

A. Both No. 1 and No. 2 are true.

On a twin-engine aircraft with fuel-injected reciprocating engines, one fuel-flow indicator reads considerably higher than the other in all engine operating configurations. What is the probable cause of this indication?

A. Carburetor icing.

B. One or more fuel nozzles are clogged.

C. Alternate air door stuck open.

B. One or more fuel nozzles are clogged.

Motor-driven impeller and turbine fuel flow transmitters are designed to transmit data

A. Using aircraft electrical system power

B. By fuel pressure

C. Mechanically

A. Using aircraft electrical system power

(1) Engine pressure ratio (EPR) is a ratio of the exhaust gas pressure to the engine inlet air pressure, and indicates the thrust produced.

(2) Engine pressure ratio (EPR) is a ratio of the exhaust gas pressure to the engine inlet air pressure, and indicates volumetric efficiency.

Regarding the above statements,

A. Only No. 1 is true.

B. Both No. 1 & No. 2 are true.

C. Only No. 2 is true.

A. Only No. 1 is true.

Engine oil temperature gauges indicate the temperature of the oil

A. In the oil storage tank

B. Entering the engine

C. Entering the oil cooler

B. Entering the engine

What basic meter is used to indicate cylinder head temperature in most aircraft?

A. Thermocouple-type meter

B. Electrodynamometer

C. Galvanometer

C. Galvanometer

A manifold pressure gauge is designed to

A. Indicate differential pressure between the intake manifold and atmospheric pressure.

B. Maintain constant pressure in the intake manifold.

C. Indicate absolute pressure in the intake manifold.

C. Indicate absolute pressure in the intake manifold.

Basically, the indicator of a tachometer system is responsive to change in

A. Frequency

B. Voltage

C. Current flow

A. Frequency

A complete break in the line between the manifold pressure gauge and the induction system will be indicated by the gauge registering

A. Zero

B. Prevailing atmospheric pressure

C. Lower than normal for conditions prevailing

B. Prevailing atmospheric pressure

Which statement is true regarding a thermocouple type cylinder head temperature measuring system?

A. The voltage output of a thermocouple system is determined by the temperature difference between the two ends of the thermocouple.

B. When the master switch is turned on, a thermocouple indicator will move off-scale to the low side.

C. The resistance required for cylinder head temperature indicators is measured in farads.

A. The voltage output of a thermocouple system is determined by the temperature difference between the two ends of the thermocouple.

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

A. A difference in the voltage between two dissimilar metals.

B. Resistance changes in two dissimilar metals.

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

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

In a turbine engine, where is the turbine discharge pressure indicator sensor located?

A. At the aft end of the compressor section.

B. At a location in the exhaust cone that is determined to be subjected to the highest pressures.

C. Immediately aft of the last turbine stage.

C. Immediately aft of the last turbine stage.

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

A. Bourdon tube

B. Diaphragm or bellows

C. Vane with calibrated spring

A. Bourdon tube

The fuel-flow indication data sent from motor-driven impeller and turbine, and motorless type fuel flow transmitters is a measure of

A. Fuel mass-flow

B. Engine burner pressure drop

C. Fuel volume-flow

A. Fuel mass-flow

Which of the following types of electric motors are commonly used in electric tachometers?

A. Direct current, series-wound motors

B. Synchronous motors

C. Direct current, shunt-wound motors

B. Synchronous motors

A Bourdon-tube instrument may be used to indicate

1. Pressure

2. Temperature

3. Position

4. Quantity

A. 2 and 4

B. 1 and 2

C. 1 and 3

B. 1 and 2

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

A. Voltage

B. Frequency

C. Current

B. Frequency

The purpose of an exhaust gas analyzer is to indicate the

A. Brake specific fuel consumption.

B. Temperature of the exhaust gases in the exhaust manifold.

C. Fuel/air ratio being burned in the cylinders.

C. Fuel/air ratio being burned in the cylinders.

Which unit most accurately indicates fuel consumption of a reciprocating engine?

A. Electronic fuel quantity indicator

B. Fuel pressure gauge

C. Fuel flowmeter

C. Fuel flowmeter

A common type of electrically operated oil temperature gauge utilizes

A. Vapor pressure and pressure switches.

B. A thermocouple type circuit.

C. Either a wheatstone bridge or ratiometer circuit.

C. Either a wheatstone bridge or ratiometer circuit.

Where are the hot and cold junctions located in an engine cylinder temperature indicating system?

A. Both junctions are located at the cylinder.

B. The hot junction is located at the cylinder and the cold junction is located at the instrument.

C. Both junctions are located at the instrument.

B. The hot junction is located at the cylinder and the cold junction is located at the instrument.

An indication of unregulated power changes that result in continual drift of manifold pressure indication on a turbo-supercharged aircraft engine is known as

A. Bootstrapping

B. Waste gate fluctuation

C. Overshoot

A. Bootstrapping

In regard to using a turbine engine oil analysis program, which of the following is NOT true?

A. It is best to start an oil analysis program on an engine when it is new.

B. A successful oil analysis program should be run over an engine's total operating life so that normal trends can be established.

C. Generally, an accurate trend forecast may be made after an engine's first oil sample analysis.

C. Generally, an accurate trend forecast may be made after an engine's first oil sample analysis.

The thermocouple leads used to measure cylinder temperature on an aircraft reciprocating engine

A. Connected to the cylinder can only be bayonet type.

B. Should be cut and trimmed to fit if the lead is too long.

C. Are connected to the electrical wiring on one end and the cylinder on the other end.

C. Are connected to the electrical wiring on one end and the cylinder on the other end.

The exhaust gas temperature (EGT) indicator on a gas turbine engine provides a relative indication of the

A. Turbine inlet temperature

B. Temperature of the exhaust gases as they pass the exhaust cone

C. Exhaust temperature

A. Turbine inlet temperature

What is the primary purpose of the tachometer on an axial-compressor turbine engine?

A. Monitor engine RPM during cruise conditions.

B. Monitor engine RPM during starting and to indicate overspeed conditions.

C. It is the most accurate instrument for establishing thrust settings under all conditions.

B. Monitor engine RPM during starting and to indicate overspeed conditions.

On an aircraft turbine engine, operating at a constant power, the application of engine anti-icing will result in

A. An increase in EPR.

B. A false EPR reading.

C. Noticeable shift in EPR.

C. Noticeable shift in EPR.

In addition to fuel quantity, a computerized fuel system (CFS) with a totalizer-indicator provides an 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

A. Four

B. Two

C. Three

C. Three

n what units are turbine engine tachometers calibrated?

A. Percent of engine pressure ratio

B. Percent of engine RPM

C. Actual engine RPM

B. Percent of engine RPM

What instrument on a gas turbine engine should be monitored to minimize the possibility of a "hot" start?

A. RPM indicator

B. Turbine inlet temperature

C. Torquemeter

B. Turbine inlet temperature

What unit in a tachometer system sends information to the indicator?

A. The synchronous motor.

B. The two-phase ac generator.

C. The three-phase ac generator.

C. The three-phase ac generator.

What instrument indicates the thrust of a gas turbine engine?

A. Turbine inlet temperature indicator

B. Exhaust gas temperature indicator

C. Engine pressure ratio indicator

C. Engine pressure ratio indicator

The EGT gauge used with reciprocating engines is primarily used to furnish temperature readings in order to

A. Obtain the best mixture setting for fuel efficiency.

B. Prevent engine over-temperature.

C. Obtain the best mixture setting for engine cooling.

A. Obtain the best mixture setting for fuel efficiency.

If the thermocouple leads were inadvertently crossed at installation, what would the cylinder temperature gauge pointer indicate?

A. Normal temperature for prevailing condition.

B. Moves off-scale on the zero side of the meter.

C. Moves off-scale on the high side of the meter.

B. Moves off-scale on the zero side of the meter.

Engine pressure ratio is determined by

A. Multiplying engine inlet total pressure by turbine outlet total pressure.

B. Dividing engine inlet total pressure by turbine outlet total pressure.

C. Dividing turbine outlet total pressure by engine inlet total pressure.

C. Dividing turbine outlet total pressure by engine inlet total pressure.

(1)  Powerplant instrument range markings show whether the current state of the powerplant operation is normal, acceptable for a limited time, or unauthorized.

(2)  Powerplant instrument range markings are based on installed engine operating limits which may not exceed (but are not necessarily equal to) those limits shown on the engine Type Certificate Data Sheet.

Regarding the above statements,

A. Only No. 1 is true.

B. Neither No. 1 nor No. 2 is true.

C. Both No. 1 & No. 2 are true.

C. Both No. 1 & No. 2 are true.

Instruments that provide readings of low or negative pressure, such as manifold pressure gauges, are usually what type?

A. Vane with calibrated spring

B. Diaphragm or bellows

C. Bourdon tube

B. Diaphragm or bellows

In an aircraft equipped with a pressure-drop type fuel-flow indicating system, if one of the injector nozzles becomes restricted, this would cause a decrease in fuel flow with

A. No change in fuel flow indication on the gauge.

B. A decreased fuel flow indication on the gauge.

C. An increased fuel flow indication on the gauge.

C. An increased fuel flow indication on the gauge.

The fuel-flow indication system used with many fuel-injected opposed engine airplanes utilizes a measure of

A. Fuel flow mass

B. Fuel pressure

C. Fuel flow volume

B. Fuel pressure

What would be the possible cause if a gas turbine engine has high exhaust gas temperature, high fuel flow, and low RPM at all engine power settings?

A. Turbine damage or loss of turbine efficiency.

B. Fuel control out of adjustment.

C. Loose or corroded thermocouple probes for the EGT indicator.

A. Turbine damage or loss of turbine efficiency.