15.14 Engine Indication Systems

Question 1

If oil pressure decreases below limit then what happens to the low pressure oil switch?

Answer 1

Closes

Question 2

What is the low oil pressure switch connected too?

Answer 2

Oil supply line and oil tank vent line

Question 3

What 2 indications show thrust?

Answer 3

N1 and EPR

Question 4

What does a strain gauge transmitter measure?

Answer 4

Mechanical strain in proportion to strain resistance

Question 5

What are the 2 types of oil pressure transmitters?

Answer 5

Bourdon tube and strain gauge

Question 6

What is the most common arrangement of a strain gauge transmitter?

Answer 6

Wheatstone bridge configuration

Question 7

What is the most common oil temperature sensor used?

Answer 7

Resistance Temperature Detector (RTD)

Question 8

When is flexible take off (FLEX) used - airbus?

Answer 8

Used as a standard take off setting unless there are performance restraints

Question 9

What is used instead of FLEX when there is a performance restraint?

Answer 9

TOGA (full thrust)

Question 10

What does an oil temperature indicator monitor?

Answer 10

Temperature of oil as it enters the oil pressure pump

Question 11

What does the oil pressure indicator show?

Answer 11

Engine oil pump discharge pressure

Question 12

Is engine trend monitoring shown on the flight deck displays?

Answer 12

No

Question 13

Where is the highest temperature on the engine found?

Answer 13

Directly behind the combustion chamber, where gas hits the HP turbine

Question 14

What is the hottest temperature of the engine known as?

Answer 14

Turbine Inlet Temperature (TIT)

Question 15

Where is EGT measured from?

Answer 15

Between the HP and LP turbine or directly behind the LP turbine

Question 16

Where are thermocouples located?

Answer 16

In spaced intervals around the engine exhaust duct or turbine casing

Question 17

When does the over temperature warning light illuminate in the flight deck?

Answer 17

When TIT reaches its limit

Question 18

Do flight deck instrumentation systems use resistance type indicators for temperature information?

Answer 18

No

Question 19

What does EPR measure?

Answer 19

Compares engine turbine discharge pressure to pressure if ram air at engine inlet

Question 20

What does the blue circle on an EPR indication in the flight deck refer to?

Answer 20

Actual throttle position

Question 21

What does the amber/red line on an EPR indication in the flight deck refer to?

Answer 21

Maximum available thrust

Question 22

What do light reciprocating engine aircraft use to monitor fuel pressure?

Answer 22

A bourdon tube pressure gauge

Question 23

Where is the fuel pressure gauge often connected to and from?

Answer 23

Connected to the fuel inlet of the fuel metering device with a line connecting back to the instrument gauge

Question 24

If an aircraft has an auxiliary pump then what does the fuel pressure gauge monitors whilst engine is starting? What does it monitor after the engine is started?

Answer 24

Monitors auxiliary pump until engine has started then monitors engine driven pump

Question 25

What do larger reciprocating and complex engine aircraft use to measure fuel pressure?

Answer 25

Bellows type pressure gauge

Question 26

What does a bellow type pressure gauge compare to receive fuel pressure information?

Answer 26

Compares fuel inlet pressure to air inlet pressure at the fuel metering device

Question 27

What do most turbine powered aircraft use after the outlet of each fuel boost pump?

Answer 27

Low pressure warning switch

Question 28

What are the 2 types of accelerometers?

Answer 28

Electromagnetic and piezoelectric crystal

Question 29

Are vibration sensors accelerometers?

Answer 29

Yes

Question 30

What 2 fuel flow indications for flight crew see?

Answer 30

Actual fuel flow to engine and fuel used since engine started

Question 31

What would cause the vibration monitoring to automatically switch to a secondary screen?

Answer 31

A vibration of more than 4.0 scalar units

Question 32

Why is fuel temperature monitored?

Answer 32

To ensure no ice forms in fuel system and filter

Question 33

What can be used to correct some low fuel temperatures?

Answer 33

A fuel heater

Question 34

What do turbine aircraft use to monitor fuel temperature? Where is it located?

Answer 34

Resistance type electric fuel temperature sensor. In main fuel tank

Question 35

If the N1 and N2 speed signals were to fail, then what indication would show on the display?

Answer 35

Broadband vibration (BB)

Question 36

What are the 2 types of fuel flow transmitters?

Answer 36

Synchronous mass flow and motorless mass flow

Question 37

What do fuel flow transmitters do?

Answer 37

Measure mass of flow of fuel between FCU and fuel nozzles

Question 38

What is the vibration computer known as?

Answer 38

Engine Vibration Monitoring Unit (EVMU)

Question 39

What does the EVMU do?

Answer 39

Collects vibration data which can show rotor imbalance

Question 40

What does the red line limit on the rotor speed indication refer too?

Answer 40

Maximum permitted rotor speed

Question 41

What are the 2 types of rotor speed sensors?

Answer 41

Variable reluctance type and tachometer generator type

Question 42

Where is the tachometer generator rotor speed sensor located?

Answer 42

On the gearbox

Question 43

How does he tachometer generator type of rotor speed sensor work?

Answer 43

The gearbox drives a permanent magnet proportional N2 rotor speed which generates a 3 phase AC voltage

Question 44

How does the variable reluctance type rotor speed sensor work?

Answer 44

Detects changes in magnetic flux between a magnet and ferromagnetic target which induces a voltage

Question 45

What is the critical part of a variable reluctance type rotor speed sensor? Why?

Answer 45

The air gap. As air gap increases, magnetic reluctance increases

Question 46

What signal does a tachometer generator provide in relation to the HP fuel cock?

Answer 46

Provides a signal which illuminates a warning lamp during the engine start cycle, telling the flight crew to open the HP fuel cock

Question 47

What are the 2 forms of torque meters?

Answer 47

Electric and hydraulic

Question 48

What engines are torque meters used on?

Answer 48

Turbo shaft

Question 49

After carrying out maintenance on an engine or an engine change, what test must be carried out?

Answer 49

Power assurance test

Question 50

What is a power assurance test?

Answer 50

Checks engine can accelerate from idle to a given EPR value within a specific time and decelerate back

Question 51

Does a hydraulic torque meter require calibration? Why?

Answer 51

Yes. It is used to set power systems