ENGINE INSTRUMENTS Flashcards
- What type of sensor is used to measure the output of a low pressure booster pump:
c. bellows
- A vibration meter measures:
b. amplitude at a given frequency
3. Which of the following are used to measure temperature? thermocouple resistance reactance mercury
b. 1, 2, & 4
- A millivoltmeter measuring electromotive force between a hot and a cold junction of a thermocouple can be graduated to read temperature if:
d. the cold junction is maintained at a constant temperature
- If both displays of an EICAS system fail what information will be displayed on the standby engine indicator:
b. N1,EPR, EGT
- A capacitive type gauging system may measure mass due to:
c. fuel dielectric constant being twice that of air and proportional to density
If the intake probe of an EPR system becomes blocked with ice this will cause the EPR gauge to:
b. over-read during take off
The power output of a turbo-propeller aircraft is measured by the amount of torque being produced. The indication can be in which of the following units.
- Newton metres
- PSI
- Percentage
- Pounds feet
- EPR
d. 1, 2, 3, 4
If one probe of a multi-sensor T.G.T. system failed , the reading would:
c. be practically unaffected
During the take-off run , the effect of increasing airspeed is to cause the EPR indication to:
c. decrease
A supercharged aircraft is climbing at its maximum permitted boost of 8 psi (16in.Hg) from sea level to its full throttle height of 10,000 feet. If sea level pressure is 29.92in.Hg , when the aircraft reaches 5000 feet, where the pressure is 24.72in.Hg, what will be the approximate indication on the MAP gauge:
d. 46 in Hg
13 An aircraft has a compensated capacitance fuel contents gauging system and is refuelled so that the total fuel contents are 76000kg at a temperature of 18 degrees C and an S.G. of 0.81. Whilst the aircraft is parked the temperature increases to 26 degrees C and the S.G. becomes 0.80. The indicated fuel contents have:
d. remained the same
- The working principle of a capacitive fuel contents gauging system is based upon:
b. changes in capacitance
- A volumetric fuel flow meter is different to a mass flow meter because the mass flow meter compensates for:
b. density
- Cylinder head temperature measurement works on the principle of:
d. thermocouple
- The electrical tacho generator system uses:
b. three phase a.c. whose frequency varies with the speed of the engine delivered to a three phase synchronous motor (squirrel cage) and drag cup.
- Where very accurate temperature indication is required the indicator used will be:
ratiometer
- Total Air Temperature (TAT) is equal to:
a. SAT + ram rise
- The principle of the fuel-monitoring device giving the fuel burnt is:
d. integration of instantaneous flow
- To measure the fuel quantity on a heavy aircraft we use:
- capacitor gauges
- electric gauges with round floats
- the indication can directly be indicated as a mass
- the indication can not be indicated as a mass
The combination of all correct statements is:
d. 1, 3
- For a capacitor gauge:
- the fuel dielectric value is half that of air
- the fuel dielectric value varies proportionally to the temperature of the fuel
- the probes are connected in parallel
- fuel dielectric value varies inversely with the fuel level
- the gauge accuracy is within 2%
The correct statements are:
a. 3, 5
- The capacitor gauge principle is based on:
a. variation of capacitance of a capacitor with the nature of the dielectric
24. Among the following parameters: EGT EPR FF N1 N2 Oil pressure Fuel pressure The ones that can be used to monitor a gas turbine thrust setting are:
b. EGT, N1, FF, EPR
- The most significant parameters and the most important that express the thrust of a gas turbine engine are:
d. N1 and EPR
- On a modern twin spool turbofan, the main handling parameter is:
d. the rotational speed of the low-pressure compressor
- Two main indications used to evaluate a turbojet thrust are:
c. fan rotational speed (N1) or EPR
- The measure of a torque can be made by measuring:
a. oil pressure at a fixed crown of an epicyclical reduction gear of the transmission box
- Among these instruments, which one uses aneroid capsules?
a. oil thermometer
b. air intake pressure sensor
c. oil pressure sensor
d. fuel pressure sensor
b. air intake pressure sensor
- In a three phase tachometer installation:
- the transmitter is a DC generator
- we measure an EMF proportional to the driving speed of the transmitter
- we measure a frequency proportional to the driving speed of the transmitter
- the receiver is a galvometer
- the receiver is an synchronised motor driving a magnetic tachometer
The correct statements are:
d. 3, 5
- The working principle of mass flow meters mostly used now days, is to measure in their system:
d. kinetic energy transmitted
- The advantage of a ratiometer is:
does not suffer from errors due to variations of supply voltage
- What is a synchroscope used for?
allowing the pilot to adjust several engines to the same RPM
- On an EICAS display what does the yellow arc on the temperature gauge signify?
b. Exceptional operating range
- An RPM gauge has a red line at the upper end of the green arc, in the middle of the green arc is a smaller red arc. What is the significance of this smaller red arc?
a. it indicates an RPM that must not be used continuously because of the increased vibration level from the engine/propeller
- In an ECAM system if a caution message appears the system will:
b. display a diagrammatic view of the affected system
- A cylinder head temperature measuring system in a piston engine has a sensor:
c. One in the hottest running cylinder
- The principles used in an electrical RPM indicating system are:
Tacho probe and phonic wheel
DC generator producing AC
3 phase AC generator driving a 3 phase AC motor
Single phase AC generator driving a single phase AC motor
b. 1 and 3
- What does the yellow band on an EICAS generated engine gauge indicate?
a. Precautionary operating range
- Advantage of a ratiometer type measuring circuit is:
a. Very Accurate
- In a Turbojet thrust is measured by:
b. N1 and EPR
- How will a system failure warning be shown to the pilot in the ECAM system:
c. The master warning will illuminate and the primary screen will display a check list
while the secondary shows a graphical display of the problem
- What is used to measure gas turbine inlet pressure?
d. Bellows
- What does a bourdon tube measure ?
d. Pressure
- What are the disadvantages of an electrical float fuel quantity measuring system
- Attitude
- Acceleration
- Temperature
- Ambient pressure
- Needs an AC power supply
b. 1, 2, 3
- How can temperature be measured?
- Resistance
- Mercury
- Thermocouple
- Reactance
c. 1,2,3
- A Thermocouple would normally be used to measure the temperature of the:
a. Turbine
- The Bourdon Tube is used in:
c. Pressure measurement
- The principle upon which flowmeters (mass flow) most commonly used today work, is to measure:
d. The Kinetic energy transferred
- A small turbine placed in the flow of fuel to the burners of a Gas Turbine engine measures:
a. Volume of flow by the measurement of magnetic impulses
- The torquemeter is an instrument:
d. Allowing the determination of the power from the propeller by using a formula which
is a function of the RPM
- Torque can be calculated in a torquemeter system by the measurement:
a. Of the oil pressure resisting lateral movement of the gearing in an epicyclic reduction gearbox
- EPR is a:
d. ratio between exhaust pressure and intake pressure.