Fire protection

Question 1

How many extinguishing bottles are on-board the aircraft?

Answer 1

Five :
- Two bottles (A and B) for engines
- One for APU
- One High-rate and one Low-rate discharge for cargo compartments

Question 2

What does a « Class C » cargo compartment mean?

Answer 2

Class C indicates the cargo compartment is protected against damage by fire.

It incorporates a fire detection and extinguishing system.

Question 3

Are the lavatories protected against fire?

Answer 3

Yes, each has one smoke detector and one integrated fire extinguisher (in waste compartment)

Question 4

How many fire extinguishers are on-board?

Answer 4

Five, one in cockpit, two in FWD galley, two in AFT galley.

Question 5

How does the engine fire detection system work?

Answer 5

2 loops (A and B) of 4 pneumatic fire detectors on each engine.

Loop A Engine 1 and Loop B Engine 2 are connected to MAU 1, powered by DC ESS Bus 1

Loop B Engine 1 and Loop A Engine 2 are connected to MAU 3, powered by DC ESS Bus 2

Question 6

How is an engine fire indicated?

Answer 6

• Associated fire handle illuminates
• Master warning
• Aural warning
• EICAS message
• FIRE on ITT indicator

Question 7

How does the APU fire detection system work?

Answer 7

2 loops with one detector each. Loop A on MAU 1, loop B on MAU 3

Question 8

What happens in case of a APU fire?

Answer 8

APU Emer Stop button illuminates. If not pressed :
- APU Fire Ext button illuminates after 1 min
- APU automatically shuts down after 10 sec on ground

Question 9

What happens when you press APU Fire Ext button?

Answer 9

• APU bottle discharges in APU compartment
• APU fuel SOV closes

Question 10

Where do the bottles take electricity from?

Answer 10

• Engine bottle A is on HOT BATT Bus 1
• Engine bottle B is on HOT BATT Bus 2
• APU bottle is on DC ESS Bus 2

Question 11

How are the lavs smoke detectors powered?

Answer 11

FWD Lav is powered by DC ESS Bus 1
AFT Lav is powered by DC ESS Bus 2

Question 12

What does an engine fire handle do when pulled?

Answer 12

Closes :
- Fuel SOV
- Hydraulic SOV
- Bleed Air SOV

Question 13

What happens when you press FWD or AFT Cargo Fire Ext button?

Answer 13

First the high-rate bottle is discharged in the associated compartment.

1 min after, low-rate bottle starts to discharge (approx. 60 minutes to empty the bottle)

You can also manually discharge the low-rate bottle manually by pressing the button a 2nd time. This is mandatory on the ground.