(8257 - 8309) Engine Instrument Systems
8291: An indication of unregulated power changes that result in continual drift of manifold pressure indication on turbosupercharged aircraft engines is known as what?
Bootstrapping
8306: Instruments that measure relatively high fluid pressures, such as oil pressure gauges, are usually what type?
Bourdon tube
8292: What instument condition is acceptable and does NOT require immediate correction?
Case paint chipped
8288: Jet engine thermocouples are usually constructed of what?
Chromel-alumel
8305: Instruments that provide readings of low or negative pressure, such as manifold pressure gauges, are usually what type?
Diaphragm or bellows.
8287: What is Engine Pressure Ratio determined by?
Dividing turbine outlet total pressure by engine inlet total pressure.
8280: A common type of electrically operated oil temperature gauge utilizes what?
Either a wheatstone bridge or ratiometer circuit.
8282: What are instrument range markings based off of?
Engine operating limits which may not exceed those limits shown on the engine Type Certificate Data Sheet.
8302:What instrument indicates the thrust of a gas turbine engine?
Engine pressure ratio indicator.
8277: Engine oil temperature gauges indicate the temperature of the oil where?
Entering the engine
8289: What discrepancies are cause for instrument replacement?
- Cracked glass - Will no zero out - Pointer loose on shaft - Fogged
8264: In addition to fuel quantity, a computerized fuel system (CFS) with a totalizer-indicator provides indication of what?
- Fuel flow rate - Fuel used since reset or initial startup - Fuel time remaining at current power setting
8293-1: What factors affect average pressure inside the cylinder of a reciprocating engine?
- Manifold pressure - Compression ratio of the engine
8290: A Bourdon-tube instrument may be used to indicate what?
- Pressure - Temperature
8286: What are the two indicators that some engines use to determine the amount of thrust produced?
- RPM - EPR
8281: The indication on a thermocouple-type cylinder head temperature indicator is produced by what?
A current generated by the temperature difference between dissimilar metal hot and cold junctions
8295: In regard to using a turbine engine oil analysis program, how may an accurate trend forecast be made?
A forecast can be made after a few samples are analyzed. A trend cannot be determined after just one sample.
8296: On an aircraft turbine engine, operating at constant power, the application of engine anti-icing will result in what?
A noticeable shift in EPR
8261: The fuel-flow indicator rotor and needle for a motor impeller and turbine indicating system is driven by
An electrical signal
8283: How are thermocouple leads designed?
Foe specific installation and may not be altered.
8271: Basically, the indicator of a tachometer system is responsive to change in
Frequency
8307: The RPM indication of a synchronous AC motor tachometer is governed by the generator's what?
Frequency.
8257: Which unit most accurately indicates fuel consumption of a reciprocating engine?
Fuel flowmeter
8263: The fuel-flow indication system used with many fuel-injected opposed engine airplanes utilizes a measure of what?
Fuel pressure
8274: What basic meter is used to indicate cylinder head temperature in most aircraft?
Galvanometer
8259: The principal 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
Higher than normal fuel flow indication.
8303: In a turbine engine, where is the turbine discharge pressure indicator sensor located?
Immediately aft of the last turbine stage
8286: What does it mean when a turbine engine indicates high EGT for a particular EPR, when there is no significant damage?
It means the engine is out of trim.
8272: What statement is correct concerning a thermocouple-type temperature indicating instrument system?
It requires no external power source.
8284: What is Engine Pressure Ratio, and what does it indicate?
It's a ratio of the exhaust gas pressure to the inlet air pressure, and indicates the thrust produced.
8293: A change in engine manifold pressure has a direct effect on the
Mean effective cylinder pressure.
8299: What is the primary purpose of the tachometer on an axial-compressor turbine engine?
Monitor engine RPM during starting and to indicate overspeed conditions
8279: If the thermocouple leads were inadvertently crossed at installation, what would the cylinder temperature gauge pointer indicate?
Moves off-scale on the zero side of the meter.
8278: Why do helicopters require a minimum of two synchornous tachometer systems?
One indicates engine RPM and the other indicates main rotor RPM
8262: 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?
One or more fuel nozzles are clogged.
8304: In what units are turbine tachometers calibrated?
Percent of engine RPM
8276: A complete break in the line between the manifold pressure gauge and the induction system will be indicated by the gauge registering
Prevailing atmospheric pressure
8269: What type of electric motor is commonly used in electric tachometers?
Synchronous motors
8275: Which of the following is a primary engine instrument?
Tachometer
8297: Engine pressure ratio is the total pressure ratio between what?
The front of the compressor and the rear of the turbine.
8258: The fuel flowmeter used with a continuous-fuel injection system installed on an aircraft horizontally opposed reciprocating engines measures the fuel pressure drop across what?
The fuel nozzles
8268: The purpose of an exhaust gas analyzer is to indicate what?
The fuel/air ratio burned in the cylinders.
(8270) - Where are the hot and cold junctions located in an engine cylinder temperature indicating system?
The hot junction is located at the cylinder and the cold junction is located at the instrument.
8309: A Red triangle, dot, or diamond mark on an engine instrument face or glass indicated what?
The maximum starting limit for transients such as starting.
8285: What unit in a tachometer system sends information to the indicator?
The three-phase AC generator
8273: What statement is true regarding a thermocouple-type cylinder head temperature measuring system?
The voltage output of a thermocouple system is determined by the temperature difference between the two ends of the thermocouple.
8282: What do instrument range markings mean?
They show whether the current state of powerplant operation is normal, acceptable for a limited time, or unauthorized.
8308: The EGT gauge used with reciprocating engines is primarily used to furnish temperature recordings in order to do what?
To obtain the best mixture setting for fuel efficiency.
8298: 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?
Turbine damage or loss of turbine efficiency.
8294: What instrument on a gas turbine engine should be monitored to minimize the possibility of a hot start?
Turbine inlet temperature
8301: The exhaust gas temperature (EGT) indicator on a gas turbine engine provides a relative indication of the what?
Turbine inlet temperature.
8266: 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
an increased fuel flow indication on the gauge.
8300: The engine pressure ratio (EPR) indicator is a direct indication of what?
engine thrust being produced.
8265: The fuel-flow indication data sent from motor driven impeller and turbine, and motorless type fuel flow transmitter is a measure of what?
fuel mass-flow
8267: A manifold pressure gauge is designed to do what?
indicate absolute pressure in the intake manifold
(8260) - Motor driven impeller and turbine fuel flow transmitters are designed to transmit data
using aircraft electrical system power
