Engine Instrument Systems Flashcards
(32 cards)
What are three types of flow-indicating systems used for turbine engines?
-Vane-type meters
-Synchronous mass-type flow meters
-Electronic motorless mass flow meters
What do mass flow systems measure>
The mass of the flow. This is affected by the density of the fuel which is in turn affected by the fuel temperature.
In what units an electronic motorless mass flow meter system calibrated?
Pounds per hour of fuel flow.
What is indicated in a turbine engine if the fuel flow for all conditions is high?
If there are other instrument abnormalities, there are possibly damaged turbine components.
Who is authorized to repair a fuel flow indicating system?
The components can be repaired only by an FAA approved repair station certificated for the particular instruments.
Where can you fund the electrical power requirements for a fuel flow indicating system?
In the aircraft maintenance manual.
Where in the fuel system is the fuel flow transmitter located?
Between the fuel control and the fuel nozzles.
What kind of indicating system is used to measure oil temperature in a small, single-engine, general aviation airplane?
A sealed system in which a bulb, partially filled with a highly volatile liquid, is installed inside the oil strainer. The bulb is connected to a pressure gauge by a copper tube. the pressure of the gas above the liquid is proportional to the temperature of the oil that surrounds the bulb, and the pressure gauge is calibrated in terms of temperature.
What type of instrument system is used for measuring cylinder-head temperature and exhaust gas temperature?
A thermocouple system.
What kind of electrical instrument system is used for measuring oil temperature?
A ratiometer-type system.
What should a thermocouple cylinder-head temperature indicator read when the engine is cold?
The same as the outside air temperature gauge.
What is critical in the installation of the thermocouple leads for a cylinder-head temperature indicator, the length of the leads or their resistance?
The resistance is critical, it must have the resistance specified on the indicator. This is usually 2 or 8 ohms.
What should a ratiometer temperature indicator read when the electrical power is off?
The pointer should be off scale on the low side.
How does a ratiometer-type oil temperature gauge measure the temperature of the oil?
A ratiometer measures the resistance of the temperature bulb. The indicator is calibrated in degrees Fahrenheit or Celsius rather than in ohms.
What kind of tachometer is used on most small single-engine airplanes?
A magnetic drag tachometer that is similar to an automobile speedometer.
What would likely cause the pointer of a magnetic drag tachometer to oscillate?
Either a dry cable connecting the indicator to the engine, or a kink in the cable housing.
What kind of tachometer is used on most large multi-engine airplanes?
A three-phase AC electric tachometer.
What is measured to indicate the engine RPM with a three-phase AC electric tachometer?
The frequency of the AC the tachometer generator produces.
What kind of indicator mechanism is used to measure oil pressure?
A Bourdon tube.
What kind of indicator mechanism is sued to measure manifold pressure?
A differential bellows.
What should a manifold pressure gauge read when the engine is not operating?
The existing barometric pressure as indicated on the altimeter barometric scale when the altimeter pointers are set to the surveyed field elevation.
What type of fitting is used to connect an oil pressure gauge to the engine?
A fitting with a restrictor that smooths out the pulsations and should a break occur in the indicator line, prevents a serious loss of engine oil.
What is used to fill the line between a fuel pressure gauge and the fuel metering system?
A light oil such as kerosine.
What could cause a fuel pressure gauge to fluctuate?
The loss of the light oil in the line between the gauge and the engine.
