15.14

Question 1

Where is the hottest temperature

Answer 1

Directly behind the combustion chamber is where the gas hits the HPT

Called (TIT)

Question 2

Temperature of TIT

Answer 2

Higher then 1400 degrees C

Question 3

What has a direct relationship to the TIT

Answer 3

EGT

(Max can be 600-900 degrees C )

Question 4

Where is EGT taken from

Answer 4

Between high and low pressure turbine or behind the low pressure turbine

Question 5

What part of the engine is temperature taken from

Answer 5

First stage turbine inlet guide vanes

Question 6

What component measures temperature

Answer 6

Thermocouples

Question 7

How are thermocouples placed

Answer 7

Around the permitter of the engine turbine casing or exhaust duct

Question 8

What are the parts of the dual thermocouple

Answer 8

Two electrically independent junctions within a single probe

Question 9

What are primary indicators

Answer 9

Performance indications which monitor performance and set thrust for flight phases

Question 10

What are secondary indications

Answer 10

System indications which measure operation of the engine and detect malfunctions

Question 11

What is engine trend monitoring

Answer 11

Done on ground to detect engine problems at an early stage

Uses parameters recorded by ACMS

Question 12

What is the ACMS

Answer 12

Aircraft condition monitoring system

Question 13

What two parameters give us thrust

Answer 13

Rotational speed of the fan , N1

Engine pressure ratio

Question 14

What does the oil system monitor

Answer 14

Oil quantity

Oil pressure

Oil temperature

Question 15

3 analyses of engine trend monitoring

Answer 15

Thermodynamic - pressure and temperature along gas flow path

Mechanic dynamic - failure in rotors

Oil consumption

Question 16

What is compared to get epr

Answer 16

Engine turbine discharge pressure to the pressure of the ram air at the inlet of the engine

Question 17

What does the amber or redline show for EPR

Answer 17

Maximum thrust available

Question 18

What’s the blue circle in an epr indication

Answer 18

Actual throttle position

Question 19

What’s flexible take off

Answer 19

Standard take off thrust setting used on airbus

Boeing is (assumed temperature derate)

Question 20

When is full thrust (TOGA) used

Answer 20

Wet/icy condition or short runway / hot and high

Question 21

What pressure does oil pressure indicator show

Answer 21

Engine oil pump discharge pressure

Question 22

Oil pressure transmitters

Answer 22

Bourdon tube type

Strain gauge

Question 23

Shape and material of bourdon tube

Answer 23

C shaped or helical with oval cross section

Made of copper , brass , aluminium or nickel alloy (money)

Question 24

How does a strain gauge work

Answer 24

When object undergoes strain resistance changes proportionally

Question 25

Shape and material of strain gauge

Answer 25

Small rectangular shape Made of foil , metal wire or semiconductor materials

Question 26

How does a low oil pressure switch work

Answer 26

When pressure is below a limit switch closes and signal sent to computer as a warning

Question 27

What are the two types of oil temperature sensor

Answer 27

Resistance temperature detector Thermocouple ( 2 dissimilar metals )

Question 28

How is cavitation caused

Answer 28

High fuel pump demand

Question 29

What kind of warning do fuel sensors give

Answer 29

Impeding blockage and risk of cavitation

Question 30

When an auxiliary pump on an aircraft is off how is pressure created

Answer 30

Pressure created by the engine driven pump

Question 31

What warning switch is used on turbine powered aircraft

Answer 31

Low pressure warning switch at the outlet of each fuel boost pump

Question 32

Where is the announciator for each switch located

Answer 32

Adjacent to the boost on/off switch on fuel panel in flight deck

Question 33

What two indications for fuel flow is there

Answer 33

Actual fuel flow Fuel used since engine start (Indicated in kg , lbs , tons)

Question 34

What’s measured on synchronous mass flow

Answer 34

Deflection angle

Question 35

How does motorless mass flow generate acceleration

Answer 35

Fuel flow

Question 36

How is rotor speed indicated

Answer 36

Percentage of 100% design speed

Question 37

Rotor speed indication main parts

Answer 37

Sensor Data transmission Indication

Question 38

What are the other names for a variable reluctance sensor

Answer 38

Magnetic reluctance sensor Magnetic pickup

Question 39

How does a variable reluctance sensor work

Answer 39

Detects change in a magnet and ferromagnetic target

Question 40

What affect does the target have to do with the magnet and air gap

Answer 40

As the target moves closer to the magnet the air gap decreases which reduces magnetic reluctance and vice versa

Question 41

How does a tachometer generator work

Answer 41

Generates 3 phase ac voltage which is sent to the FADEC to generate speed signal

Question 42

Why is the tachometer called dedicated engine

Answer 42

Supplies electrical power to the computer

Question 43

3 types of rotor speed indication

Answer 43

Clock type scale Moving vertical bar Classical electromechanical indicator

Question 44

What colour is the over speed indicator line

Answer 44

Red If engine exceeds for the duration of the overspeed it’s recorded and initiates report from engine trend monitoring

Question 45

What does vibration indicate

Answer 45

Rotor imbalance

Question 46

What the range of vibration units

Answer 46

0-6

Question 47

How many vibration sensors

Answer 47

1 or 2

Question 48

What’s the vibration computer called

Answer 48

Engine vibration monitoring unit (EVMU)

Question 49

What do accelerometers do

Answer 49

Measure the radial acceleration of the rotor system

Question 50

Where are the 2 vibration sensors located

Answer 50

Compressor area and turbine area

Question 51

What’s the electromagnetic accelerometer

Answer 51

Magnet with two springs When vibration occurs the coil moves up and down with the sensor housing

Question 52

How does a piezoelectric crystal sensor work

Answer 52

Voltage is generated when you apply a force to the crystal

Question 53

What’s shown when n1 or n2 speed signal fails

Answer 53

Broadband (BB) vibration

Question 54

What does a electrical torque meter system consist of

Answer 54

Torque meter assembly Phase detector Indicator

Question 55

How is a hydraulic torque meter operated

Answer 55

By engine oil metered through a valve that is controlled by a helical ring gear that moves in response to the applied torque

Question 56

Why is a power assurance test needed

Answer 56

Check that the engine can accelerate and decelerate to and from idle with a given epr within a specific time period

Question 57

During a power assurance test which way is the plane placed

Answer 57

Into the wind with chucks in front and behind the wheels

Question 58

How quickly should the engine accelerate and decelerate during a power assurance test

Answer 58

Accelerate to given speed - 7s or less Decelerate to idle - 8s or less

Question 59

After n1 operating above 70% how do you shut down

Answer 59

Run at idle for 10m to decrease engine temp and safely shutdown the engine

Question 60

Where is low pressure sensor in the fuel system

Answer 60

After the outlet from the low pressure filter