Fire/Smoke Detection

Question 1

Fire bottles are

Answer 1

Electrically operated manual selection by flight crew

Based upon automatic fire detection

Each engine has two fire extinguisher bottles available which are connected to fire zones via piping

Release the content if the cartridge is broken

Question 2

What happens when you pull the fire warning handle

Answer 2

Fire bottle squib will be armed

• closure of fuel shut off valve
• closure of hydraulic shut off valve
• closure of engine bleed air valve
• tripping of generator breaker
• disabling the engine thrust reverser

Question 3

Gas filled fire detection system error warning means

Answer 3

Low Pressure

Question 4

Gas filled detection system fire warning means

Answer 4

High pressure

Question 5

Gas filled fire detection system

Answer 5

If the gas in the pipe is heated pressure rises to warn the presence of fire

Question 6

Optical Smoke Detector

Answer 6

Particles of smoke scatter and reflect light
Detector has a light source and a sensor
If two or more detectors sense smoke it will trigger alarm

Question 7

Ionisation Smoke Detector

Answer 7

Small quantity of radioactive material in ionising chamber
Smoke particles absorb alpha particles
Ionisation stops so current flow stops
Lack of current flow triggers warning on flight deck

Question 8

APU Fire Zone

Answer 8

Self contained/automatic detection will cause APU to shut down

Question 9

Fire wire - Fire Detection

Answer 9

Operates on principal wire will change its resistance when heated
Can be operated with one loop for limited time
Each loop is independent of other and own controller

Question 10

Systron Donner - Gas Filled Detector

Answer 10

Two loops which gas expands to push out warning circuit

Core contains helium gas 8psi
If loop breaks gas leaks and responder unit will signal fault

Question 11

Bimetallic overheat sensor

Answer 11

Two metallic strips with low efficient of expansion
Electrical contact
Heat stretch them apart

Question 12

Armed condition for fire warning in cockpit

Answer 12

Pulling fire warning will

Cut of generators
Cut of fuel supply low pressure spar valve
Cut of hydraulic supply
Cut of bleed air/HPSOV
Detonator arms the fire extinguisher squib

Can be reversed apart from generators is pushed back in

Question 13

After arming the fire warning what is the next step

Answer 13

Rotate the red button which will fire the squib

Question 14

When fire is detected

Answer 14

Red flashing fire master caution captions (will not go out until fire detection is removed)

Sound of fire warning bell
Illuminate the ENG1 FIRE
Illuminate appropriate fire handle in cockpit

Question 15

Fire extinguisher system is a

Answer 15

2 shot system capable of sending extinguishing to either engine

Question 16

Toilets have what fire smoke/fire protection

Answer 16

Smoke detection is ionisation type
Automatic fire extinguisher straight into the waste paper bin
Freon/BCG extinguishing agent

Question 17

Fire extinguishers in engine

Answer 17

Operated by electrically fired cartridge (squib) rupturing a seal in the bottle head

Extinguishing directed to low pressure end of the engine compressor

X2 per engine

Halon extinguisher used

Question 18

Fire Wire faults meaning

Answer 18

Low resistance and low capacity - loop is faulty

Question 19

Indications of successful engine fire drill

Answer 19

The engine fire handle or button light goes out

Question 20

What warnings of an engine fire system can be cancelled

Answer 20

The audible warning and attention getting light

Red fire captions illuminated until fire is no longer detected

Question 21

Firewire works on a negative of what

Answer 21

Negative coefficient of resistance and a positive coefficient of capacitance

Question 22

Smoke Detection requirements in flight deck

Answer 22

No required

Question 23

Where would you find smoke detectors

Answer 23

Galleys, toilets and inaccessible compartments and worse case scenario area

• hydraulic bays
• cargo bays
• avionics
• electrical bays
• engines
• APU
• Cargo compartments

Question 24

Continuous Loop Fire detection system

Answer 24

Thermal detector that monitor temp and heat and responds with signal when temp exceeds limit

Changes electrical resistance with temp - as temp goes up resistance goes down and current increases. Can be reset once fire is removed as resistance will then increase again

Dual loop system both need to be triggered to activate fire warning

Question 25

Minimum loops for a 2 engine ac

Answer 25

2 loops minimum
One loop has 2 shots

Question 26

Why do bimetallic detectors have a delay before triggering

Answer 26

In order to avoid false indications caused by vibrations

Question 27

Key facts about halon extinguisher

Answer 27

Suppresses the chemical reaction of fire
Most effective fire extinguisher
Is not corrosive on aluminium