Q1. Tachometers in jet engines measure:
RPM at the crankshaft.
Percentage of maximum rpm at each shaft.
The speed of the incoming air.
All are false.
Q2. Select the wrong answer about mechanical tachometers
In the centrifugal type mass separates in proportion to the shaft rotating speed.
Friction tachometers are very common in aviation.
Magnetic drag tachometers use permanent magnets.
There are four types.
Q3. Electrical tachometers
Electrical generator with the rotor being linked to the engine rotational speed
DC or AC. It is autonomous from the electrical aircraft system.
Indicator unit is a squirrel cage induction motor fed with the current generated at detector. It is joint to a mechanism similar to the one in magnetic drag tachometers
All of above are correct.
Q4. Electronic tachometers
Magnetic field detection: permanent magnet solidary to the engine and a coil detector unit
Parasitic current detection: due to the blades crossing in front of a sensor
Both are false
Both are true
Q5. Vibration is symptomatic of an impeding problem that could be caused by
Damaged compressor / turbine blade(s)
Uneven temperature distribution around turbine blades
Q6. SEM
Process data from sensors.
Detect errors.
All are correct
Conversion volume is weight
Q7. FUEL TOTALISER:
Digitally displays the amount of fuel in each tank on a flight deck indicator and provides an indication of the total amount of fuel on board the aeroplane
Allows the crew to select the amount of fuel to be refuelled
Uses a motor driven impeller through which the fuel passes and makes the fuel swirl at a rotation rate proportional to the flow rate. Then, the swirling fuel impacts a receiver turbine, inducing a rate of rotation proportional to the swirl rate.
Q8. ENGINE INDICATION AND CREW ALERTING SYSTEM
All are true.
It is a part of the EIS
Displays primary engine indications
provides a centrally located crew alerting system for non-normal situations