Module 15.20 Fire protection systems

Question 1

Where would fire detection take place?

Answer 1

Fire zone

Question 2

What is in a fire zone?

Answer 2

Detection and/or extinguishing

Question 3

What are the two major types of turbine failure?

Answer 3

• Thermodynamic
• Mechanical

Question 4

Rapid build up go ice on inlet screens or IGV’s can result in what?

Answer 4

Severe overheating

Question 5

Generally most thermodynamic failures are cause by what?

Answer 5

• Ice
• Excess air bleed or leakage
• Faulty controls that allow compressor stall or excess fuel

Question 6

Mechanical failures, such as fractured or thrown blades, can puncture what?

Answer 6

The tail cone

Question 7

What does a complete fire protection system include?

Answer 7

Fire detection and extinguishing

Question 8

How are fires detected?

Answer 8

By using one more of the following detectors:
- Overheat
- Rate of rise
- Flame

Question 9

What are the most common types of detectors?

Answer 9

Spot detectors and continuous loop

Question 10

What detection systems are used on older aircraft?

Answer 10

• Thermal switch
• Thermocouple

Question 11

How are thermal switches connected relative to each other?

Answer 11

In parallel

Question 12

What are optical detectors sometimes referred to as?

Answer 12

Flame detectors

Question 13

What do the thermocouple control?

Answer 13

Operation of the relay

Question 14

What do the relays control?

Answer 14

The warning lights

Question 15

What are the two types of optical sensors available?

Answer 15

• Infrared
• Ultraviolet

Question 16

When would infrared detectors be used?

Answer 16

Light turboprop and helicopter engines

Question 17

What does the integrity switch do?

Answer 17

Triggers fault alarm in loss of pressure as in the case of a leak

Question 18

The pneumatic detector has what two sensing functions?

Answer 18

• Average
• Discrete

Question 19

Average temp sensing is within what range?

Answer 19

93℃ to 371℃

Question 20

Both the average and discrete functions are what?

Answer 20

Reversible

Question 21

What are the two types of continuous loop detector systems?

Answer 21

• Fenwal
• Kidde

Question 22

The fenwal system automatically returns to what after extinguishing?

Answer 22

Standby alert

Question 23

How do you know there is a fire in continuous loop system?

Answer 23

Alarm conditions on both loops

Question 24

How many shots does the APU often have?

Answer 24

One shot

Question 25

What does a High Rate Discharge system use to deliver?

Answer 25

Open end tube

Question 26

Why is Halon 1301 used

Answer 26

Effective, low toxicity and non corrosive

Question 27

Engine fire protection systems are designed to? (Gases)

Answer 27

Dilute the atmosphere with an inert agent

Question 28

How are fire bottles pressurised?

Answer 28

Nitrogen

Question 29

When can cylindrical shaped fire bottles be used?

Answer 29

When space is limited

Question 30

What is installed in the outlet of the discharge valve assembly?

Answer 30

A cartridge (squib) and frangible disc-type valve

Question 31

How is visual fire bottle pressure given?

Answer 31

Via a vibration resistant helical bourdon type indicator

Question 32

When are two way check valves required in a fire extinguishing systems?

Answer 32

Two shot system, to prevent agent backing up in the reserve container

Question 33

What does the red disc indicate?

Answer 33

Thermal discharge

Question 34

What does the yellow disc indicate?

Answer 34

Pilots have discharged it

Question 35

What fire warning systems are installed?

Answer 35

Visible and audible warning systems are installed in the flight deck to alert the flight crew

Question 36

What happens if both junctions of a thermocouple are heated at the same rate?

Answer 36

No voltage is produced

Question 37

What does the fire detection card monitor the loops for?

Answer 37

- Fire - Overheat - Faults