M15.14 Engine Indicstiing Systems

Question 1

Types of engine indication

Answer 1

• Performance indication
• System indications
• Engine trend monitoring

Question 2

Methods of indirectly measuring thrust

Answer 2

• N1 speed (fan)
• EPR

Question 3

What records the engine trend monitoring

Answer 3

ACMS

Question 4

What three analyses are completed by engine trend monitoring

Answer 4

• Thermodynamic analysis
• Mechanic-dynamic analysis
• Oil consumption analyses

Question 5

What does thermodynamic analysis check

Answer 5

• Pressure and temp along gas flow path
• Feedback from VSVs and VBVs
• Active clearance control
• Fuel flow

Question 6

What does the mechanical-dynamic analysis check

Answer 6

Mainly for failure in the rotor system (imbalances and bearing failures

Question 7

Main parts of rotor speed indication

Answer 7

• Sensor
• Data transmission
• Indication

Question 8

N1 is what

Answer 8

LP

Question 9

N2 is what

Answer 9

HP

Question 10

How are engine rotor speeds expressed

Answer 10

As a percentage of the 100%design speed

Question 11

Types of sensors that measure rotor speed

Answer 11

• Variable reluctance type sensor
• Tachometer generator type

Question 12

Where is a tachometer generator type sensor usually located

Answer 12

In the gearbox

Question 13

What converts a synchronous motor into a indication

Answer 13

Eddy current clutch

Question 14

What sensor is normally used to measure N1 speeds

Answer 14

Variable reluctance speed sensor

Question 15

Where is the variable reluctance speed sensor normally located

Answer 15

Positioned directly in line with the phonic wheel on the compressor shaft

Question 16

Types of rotor speed indication

Answer 16

• Display clock
• Moving vertical bar
• Electromechanical indicator

Question 17

What happens if the actual N1 speed exceeds the limit

Answer 17

Indications turn red along with audible warning via CWS

Can a,so be recorded in modern aircraft

Question 18

What happens after the N1 speed decreases below the allowed limit

Answer 18

Exceedence pointer records how much into overspeed it reached

Question 19

When the N1 indication is used to set the engine power what values appear on the indications

Answer 19

• N1 limit
• N1 CMD
• Reference N1

Question 20

Where does EPR measure the pressure

Answer 20

Fan inlet and turbine outlet

Question 21

What calculates EPR in modern aircraft

Answer 21

FADEC

Question 22

With systems with FADEC what measures the pressure

Answer 22

Electronic pressure transducers

Question 23

Where is the highest temperature in the engine

Answer 23

Turbine inlet temp or TIT

Question 24

How is torque measured in turbo props

Answer 24

Hydraulic or electric torque meter

Question 25

How are thermocouples used to measure EGT connected

Answer 25

Parallel

Question 26

How is engine vibration indicated

Answer 26

Level of vibration (units 0 to about 6)

Question 27

How many vibration sensors on each engine and their locations

Answer 27

One in the compressor area (Near N1 rotor) Second in the turbine area (Turbine frame)

Question 28

Types of accelerometers used in engines

Answer 28

- Electromagnetic - Piezoelectric crystal

Question 29

What is the BB vibration signal

Answer 29

Unfiltered vibration signal from the aft sensor

Question 30

What basic law is used to measure fuel flow

Answer 30

F=MA (Newtons second law)

Question 31

How many magnets are in a modern fuel flow transmitter

Answer 31

4. (2 on the drum and 2 on the impeller)

Question 32

Types of oil quantity transmitter

Answer 32

- Capacitance type - Reed switch

Question 33

Types of oil pressure sensor

Answer 33

- Bourdon tube - Strain gauge

Question 34

Types of oil temp indication

Answer 34

- Thermocouple - Thermistor

Question 35

What is used to measure internal wear of lubricated engine components

Answer 35

SOAP (Spectrometric Oil Analysis Program)