737 Fire Protection Flashcards
Which areas of the aircraft have Fire Detection systems?
Engines, APU, Main Wheel Well, Lower Cargo Compartment
Which areas have fire Extinguishing/Suppression systems?
Engine, APU, Lower cargo compartment
Which areas have both fire detection and fire extinguishing/suppression
All but Main Wheel Well
What does an illuminated Master FIRE WARN (red) light indicate? What causes it to illuminate?
FIRE or TEST
Extinguished by pushing light or using BELL CUTOUT switch
What causes the Fire Warning Bell to sound?
Comes on in conjunction with the FIRE WARN light (test or actual fire detected)
How can the Fire Warning Bell be silenced?
Pushing either FIRE WARN lights or the BELL CUTOUT.
What does an illuminated Engine Overheat (amber) light indicate?
an overheat condition
What causes the Engine Overheat (amber) light to illuminate?
The temperature of a detector has increased to a predetermined limit
What causes the Engine Overheat (amber) light to extinguish?
Temperature drops below the predetermined limit - COOLS OFF
How many engine fire extinguisher bottles are there?
2 total
Can these bottles be discharged into both engines, or only the respective engine?
2 bottles total - 2 OR 1 discharges into one engine
What powers the Engine Overheat and Fire Detection system?
Detection = BAT BUS
The Engine Fire Extinguishing system power source?
Extinguish = HOT battery bus
What does pulling the engine fire switch do?
Lighter colors panels on overhead Just think ISOLATE & VENTILATE and affects those panels
B - Bleed valve closes
R - Reverser disabled
G - Generator tripped
H - Hydraulic valve closes
F - Fuel valves close (engine fuel valve & spar valve)
S - Squibs & Switch (squib armed & switch able to be turned)
What does rotating the engine fire switch do?
Electronically “fires” a squib, discharging the extinguishing agent into the related engine. Rotating the switch the other way discharges the remaining bottle.
How many detector loops does each engine have?
2 loops
What do the loops provide?
Fire and overheat detection
What are the indications of a single loop failure?
No flight deck indication of a single loop failure
A dual loop failure?
FAULT light (with OVHT DET switch in NORMAL)
What does an illuminated FAULT (amber) light indicate?
Dual loop failure (with OVHT DET switch in NORMAL)
A or B loop failure (with switch in associated position)
What causes FAULT (amber) light to illuminate?
The fault detection loops detects a fault
What causes FAULT (amber) light to Extinguish?
Doesn’t extinguish
What does an illuminated Engine Fire (red) Switch indicate?
A fire (or a test) handle is unlocked when lit
What are indications of an engine fire?
Fire Warning Bell
Both master FIRE WARN lights illuminate
Related engine fire switch illuminates *related engine overheat alert indications likely illuminate
What are the components of the APU Fire Extinguishing system?
APU Fire switch
Single APU Fire bottle
APU bottle discharge light
How many fire extinguisher bottles does the APU fire extinguishing system have?
ONE
What does pulling the APU Fire (red) switch up do?
GBFISH G - generator tripped B - bleed valve closed F - fuel deactivated I - inlet door closed S - squib armed H - handle unlocked *auto shutdown should have occurred, but this will happen anyways if you pull the handle up*
rotating the APU Fire switch?
Fires the APU squib into the APU
Where is the APU Fire Protection Panel located, and what does it do?
RIGHT main wheel well. Same stuff as in the flight deck.
What powers the APU Fire Detection system?
Battery Bus
The APU Fire Extinguishing system?
Hot battery bus
What are the components of the Main Wheel Well Fire Protection system?
Fire detection (only) and a single fire loop in the wheel well
What does an illuminated WHEEL WELL (red) light indicate?
Indicates temp has exceeded predetermined limit
What causes the WHEEL WELL (red) light to illuminate?
Temperature sensed above predetermined limit
What causes the WHEEL WELL (red) light to Extinguish?
Temperature decreases below onset temp
What are the components of the Lower Cargo Fire Protection system?
Smoke detectors 2 fire extinguisher bottles - First bottle discharges for 60 min - Second bottle discharges for 135 additional min to maintain the level of halon in the compartment
What does an illuminated DETECTOR FAULT (amber) light indicate?
FAULT in one or more of the detectors
An illuminated Cargo Fire FWD/AFT (red) light?
One detector in each loop has detected smoke (they agree)
The FAULT/INOP and OVHT/FIRE TEST switch, when in the FAULT/INOP position, tests what?
Testing the fault detection circuitry
When in the OVHT/FIRE position? Testing what?
Testing the fire detection circuitry
