How many engine fire protection loops are there for each engine?
- 2, Loop A and Loop B, that incorporate the fire monitoring of the engine through three APD’s. (advanced pneumatic detectors)
Loop A: APD’s give fire or overheat detection for the Primary Engine Zone (PEZ), Leading Edge Zone (LEZ)
Loop B: Main Wheel Well (MWW) Zone
What area does Loop A cover?
Loop A covers the primary engine zone and leading edge zone (PEZ and LEZ).
What area does Loop B cover?
Loop B covers the main wheel well Zone (MWW).
How many fire bottles are there?
There are two dual port fire bottles installed forward and aft in the left wing root, for engine fire extinguishing.
Fire suppressant can be discharged into the left or right nacelles.
The bottles are connected in a configuration that allows for up to two suppressant discharges into an engine Nacelle.
What is the indication if a fire bottle has thermally vented?
BTL LOW advisory light, on fire protection panel
What is the indication of a fault of an engine fire loop?
- Fault A or B lights (amber) on the Fire Protection Panel illuminate.
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What are the cockpit indications of an engine fire?
- Engine fire warning tone sounds
- Both ENGINE FIRE PRESS TO RESET switch lights (red) flash
- CHECK FIRE DET warning light (red) flashes
- MASTER WARNING switchlight (red) flashes
- Related PULL FUEL/HYD OFF handle advisory light (red) comes on.
Note: the ENGINE FIRE PRESS TO RESET switchlights stay on steady until the fire overheat condition stops.
Where is the lavatory fire bottle?
In the lav waste bin.
How does the lavatory fire bottle operate?
It is thermally activated. If a fire occurs in the waste bin, fusible seals of the end caps (2) melt and release the end caps from the Discharge tubes. The suppressant is then discharged into the waste bin.
What are the indications of a lavatory fire?
- Lavatory smoke detection is only indicated in the lavatory and passenger compartment.
If smoke detector senses smoke:
- detector Audible warning tone sounds
- detector alarm light(red) comes on
- LAV SMOKE light (red) on all 3 advisory light panels (ALP), come on
- Chime (high) sounds in the cabin speakers
How many portable fire extinguishers are there?
- 4
- one in flight deck
- Three in the passenger cabin
They are Halon 1211,which are effective on electrical, oil and fuel fires. The extinguishant is not corrosive or toxic, and will not freeze or cause cold burns.
If a pilot is required to fight a fire in the cabin, protective breathing equipment (PBE) must be put on before exiting the flight deck.
What are the indications of an aft baggage compartment fire?
If one or both of the aft baggage compartment smoke detectors senses smoke, the:
- SMOKE warning light (red) flashes
- MASTER WARNING light (red) flashes (tone)
- AFT SMOKE advisory light (red) comes on
- EXTG advisory light (White) comes on
- VENT VALVE INLT advisory light (white) comes on
- VENT VALVE OTLT advisory light (white) comes on
- AFT ARM advisory light (amber) comes on
How many baggage compartment fire bottles are there?
- 3,the forward and aft baggage compartments each have a High Rate Discharge bottle and share a Low Rate Discharge bottle.
- LRD bottle is shared between the forward and aft baggage compartment, each compartment has its own separate Discharge cartridges.
- LRD bottle is located in the aft equipment bay.
When do the baggage compartment fire bottles discharge?
Pushing the SMOKE/EXTG switchlight discharges the HRD fire suppressant into the aft baggage compartment.
After a 7 minute delay, the LRD fire bottle automatically discharges into the aft baggage compartment. The seven minute delay is to maximize the amount of suppressant in the baggage compartment.
After 15-22 minutes there is still a discharge of 3% for 45 minutes until the bottle is empty.
Note: the FIRE BOTTLE FWD LOW advisory light may come on after the FIRE BOTTLE AFT LOW light comes on.
Forward baggage compartment:
When you push the red/White FWD SMOKE/ EXTG switchlight, discharges the HRD fire suppressant into fwd baggage compartment.
The LRD fire extinguisher bottle discharges at the same time.
Advanced Pneumatic Detectors in the Nacelle.
- The control amplifier monitors the pressure increase of the APD. If an overheat condition occurs, the pressure increase causes the alarm signal. The integrity switch monitors the pressure loss of the APD. If an APD breaks, the pressure loss causes the FAULT A or FAULT B light to come on.
- The PEZ and LEZ are connected in a series with the control amplifier in such a manner that if the APD in the PEZ fails, the APD in the LEZ will still give fire indications. But, if the APD in the LEZ fails, the APD in the PEZ will not give any indication. Thus, it is possible to get a FAULT A indication and an engine fire warning at the same time.
