8. Fire Protection Flashcards
APU Fire Switch UP
- Arms APU Fire Extinguisher Bottle Squib,
- Closes Fuel SOV, APU Bleed Air Valve and APU Inlet Door,
- Trips Generator Control Relay and Breaker,
- Allows APU Fire Switch to rotate,
- Provides backup for the Automatic Shutdown feature
Engine Fire Switch UP
- Arms one discharge squib on each Engine Fire Extinguisher,
- Closes Fuel (Spar & Engine) SOVs,
- Closes Hydraulic SOV and deactivates Engine Driven Hydraulic Pump LOW PRESSURE light,
- Closes Engine Bleed Air Valve resulting in loss of WAI to the affected wing
- Disables Thrust Reverser,
- Trips Generator Control Relay and Breaker,
- Allows Engine Fire Switch to rotate
FAULT Light
- With Overheat Detector Switch in NORMAL: Indicates both detector loops for an engine failed,
- Does not show single loop failure,
- MASTER CAUTION and OVHT/DET lights do not illuminate
DETECTOR FAULT
One or more of the selected loop(s) in either cargo compartment has failed
Cargo Fire FWD/AFT Warning Lights
- At least one detector in each loop detects smoke,
- With power failed in one loop, at least one detector on the remaining loop detects smoke
APU Fire Control Handle
Down:
- Arms APU BOTTLE DISCHARGE switch,
- Closes APU Fuel Shutoff, Bleed Air Valve and APU Inlet Door,
- Trips Generator Control Relay and Breaker
Lavatory Smoke Detectors
Jamco:
- When smoke activates the detector, alarm horn sounds and red Alarm Indicator light illuminates,
- A plastic or wooden probe needed to press Interrupt/Reset button,
- Customer selected Attendant Chime/Call Light and Flight Deck Alert features available,
Kidde:
- 28V DC detector when activated an alarm horn sounds and the status light illuminates steady red,
- Normal indication light is steady green,
- Blinking red means fault and blinking green means maintenance required,
- If pushed Horn Cancel switch, horn cancellation continues if no smoke sensed for 30s then the detector resets,
- If pushed and held, horn cancellation is active as long as held then the above applies,
- Horn Cancel Switch does not affect the status indicator light
Lavatory Fire Extinguisher
- TEMPERATURE INDICATOR Placard: Normally white, turns to black when exposed to high temperatures,
- Heat Activated Nozzle: Normally black, turns to alluminum when discharged,
- Both nozzles discharge toward the towel disposal container
Fire Protection Systems General
- Engines and APU has fire detection and extinguishing,
- Engines also have Overheat Detection,
- Cargo Compartment has somke detection and fire suppression,
- Main Gear Wheel Well has a Fire Detection only
Engine Overheat and Fire Detection
- Each engine contains 2 overheat/fire detector loops,
- As the temperature of a detector increases to a predetermined limit, it senses overheat condition,
- At higher temperatures, the detector senses a fire condition,
- Both Detector Loops must sense fire or overheat condition (except single loop operation)
Engine Fire Extinguishing
- Either or both 2 Fire Extinguisher bottles can be discharged into either engine,
- ENG OVERHEAT light unlocks Engine Fire switches which are normally locked
- Rotating Engine Fire switch electrically fires a squib, discharging extinguisher into the related engine,
- BOTTLE DISCHARGED illuminates after a few seconds
Engine and APU Fire Detection and Extinguishing Power Sources
- Detection: Battery Bus,
- Extinguishing: Hot Battery Bus
APU Fire Detection
- Single Fire Detection Loop,
- Only Fire condition detection (no Overheat detection)
APU Fire Extinguishing
- Single Extinguisher bottle,
- Can be discharged from Flight Deck and Main Wheel Well,
- Illumination of the APU Fire Switch unlocks the switch which is normally locked
BOTTLE DISCHARGED Light for Engine & APU
- Indicates the bottle has discharged or,
- Pressure is low
Main Wheel Well Fire Protection
- Fire detection powered by AC Transfer Bus 2 and Battery Bus,
- It has no Fire Extinguishing System,
- Single Fire Detection Loop
Cargo Compartment Fire Protection Power Source
- Smoke Detection: DC Bus 1 and 2,
- Fire Suppression: Hot Battery Bus
Cargo Compartment Smoke Detection
- FWD and AFT have Smoke Detectors in a Dual Loop configuration,
- Normally both Loops must sense smoke to cause an alert (except single loop operation),
- After the initial warning, FWD/AFT warning lights can extinguish, remain illuminated or re-illuminated
Cargo Compartment Fire Suppression
- A single Fire Extinguisher Bottle is installed in the Air Conditioning Mix Bay (forward wing spar),
- Provides Fire Suppression for a total time of 75 minutes,
- 60 minutes of flight time and 15 minutes of missed approach, landing and passenger unloading,
- DISCH light may take up to 30s to illuminate
Cargo Fire System Test
- Send signal to the FWD and AFT Cargo Fire Detector Loops and,
- Verifies continuity of the Extinguisher Bottle Squib circuits,
- After the test, up to 4s delay may occur to allow indications to extinguish
