Fire Detection And Protection System – ATA 26

Automatic Fire And Overheat Detection System Fault Testing is Continuously Preformed by the System,

If the System can Not Reconfigure and Does Not Repair the System Operation, the System Failures are Displayed on EICAS.

 -Manual Fire and Overheat Detection System Fault Testing Is Also Available, By Pushing And Holding The FIRE/OVERHEAT TEST Switch.

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APU

(One Extinguisher Bottle) – (Land At The Nearest Suitable Airport)

• Normally, Both Loops Must Detect The Fire To Activate The Fire Warning, (If A Fault Is Detected In One Loop, The System Automatically Switches To A Single Loop), In Case Of Both Loops Fail An EICAS Message DET FIRE APU

• Provides Warnings and Indications in the Flight Deck

1. The FIRE Bell Sounds
2. MASTER WARNING Light Illuminates
3. EICAS Warning Message FIRE APU Displays
4. APU FIRE SWITCH Illuminates

• Provides Warnings On The APU Ground Fire Protection Panel.

• The APU Shuts Down Automatically And The Extinguisher Bottle Will Automatically Discharge. However, It Can Be Manually Shutdown And Discharge Is Available.

• Whenever An APU Fire Is Detected, The APU Will Shutdown Immediately, And The Bottle Will Extinguish Automatically After 15 Seconds Delay To Allow Time For The Fuel Valve To Close.

• On The Ground In Unattended Mode, If Either Of The Loops Detect A Fire, Will Shutdown The APU And Extinguish The Bottle.

• EICAS Message BOTTLE DISCH APU And APU BTL DISCH On The APU Overhead Panel, Is An Indication Of The Bottle Discharge.

Once The Fire Is Extinguished, The APU FIRE EICAS Message Is Removed.

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Engines

(Two Extinguisher Bottles) – Only Manually Shutdown And Extinguished By The Crew

• Equipped with a Two Element Fire Detection and Overheat Detection Systems, normally At Least One Element on Each Channel Must Detect a FIRE SWITCH or OVERHEAT to Cause a Fire Warning or Overheat CAUTION. (If a Fault is Detected in one Channel, the Other Channel will Automatically Switch to a Single Channel), In case both channels fail an EICAS Message DET FIRE ENG L or R

• Provides WARNINGS And Indications In The Flight Deck

(When A Fire Is Detected, A Solenoid Automatically Unlocks The Fire Switch)

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• Once A FIRE SWITCH Is Pulled Out

1. Arms Both Fire Extinguishers
2. Closes The Fuel Spar Valve
3. Trips The Engine Generators
4. Closes the Engine Anti-ice Valves
5. Shuts Off Hydraulic Fluid
6. Depressurizes The Engine Driven Hydraulic Pump
7. Removes Power To The Thrust Reverser Isolation Valve

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• WARNINGS And Indications In The Flight Deck

1. The Fire Bell sounds   
2. The MASTER WARNING light illuminates
3. EICAS Warning Message FIRE ENG L or R
4. The appropriate ENG FIRE SWITCH illuminates
5. The Fire Light Illuminates On The FUEL CONTROL Switch.

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(Most Of Engine Fire Indications Remain Active Until The Fire Is Extinguished, OR Cancelled By The Master WARNING Switch, Which Will Also Silence The Bell).

• One OR Both Bottles Can Be Discharged To A single Engine And Does Not Matter Which Bottle Is Discharged First. If The Fire Is Extinguished The Engine fire Indications Are Removed.

• The Indications Of Overheat Are,

1. A CAUTION Beeper
2. Illuminated MASTER CAUTION Lights
3. An EICAS Caution message OVERHEAT ENG (L or R)

(The Overheat Caution Does NOT Unlock the FIRE Switch), An Engine Shutdown is NOT Likely if the Overheat Procedure Is Implemented And The EICAS Message Blanks

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Main Gear Wheel Well Fire Detection

Fire & Overheat Is Detected By A Dual Detector Channel

NOTE: The Nose Wheel Well Does Not Have A FIRE OR Overheat Detection System.

• Wheel Well Fire Protection Is Provided By Fire And Overheat Detection System, If Any Channel Detects A Fire OR Overheat It Will Produce The Warnings.

Warnings and Indications For a, (WHEEL WELL FIRE)

1. The FIRE BELL sounds
2. The MASTER WARNING lights illuminate
3. An EICAS Warning message FIRE WHEEL WELL Displayed

• (Pressing The MASTER WARNING Will Silence The Bell And Cancel The WARNING Lights, But The Other Indications Remain Until The Wheel Well FIRE Is No Longer Detected)

• The Wheel Well FIRE procedure Directs The Crew To Extend The Landing Gear Use of the Landing Lever And, Also The ALT GEAR Extended Switch.                                                           

              (Land At The Nearest Suitable Airport)

• Indications For A Main Wheel Well Overheat

1. The CAUTION lights Illuminate
2. The CAUTION Beeper Sounds
3. An EICAS CAUTION message OVERHEAT WHEEL WELL, Is Displayed

• (Pressing The MASTER CAUTION Will Cancel The CAUTON Lights, But The EICAS Message Remain Until the Wheel Well Overheat is No Longer is Detected)

• The Wheel Well Overheat Procedure Directs The Crew To Extend The Landing Gear To COOL The Landing Gear Then Allows For Retraction And A Normal Continuation of Normal Operations

• Indications On EICAS

1. FIRE WHEEL WELL
2. OVERHEAT WHEEL WELL
3. DET FIRE WHEEL WELL, If The System Fails.

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Cargo Compartment Fire Protection

(Five Extinguishers)

Compartment Smoke Detection And Fire Extinguishing For FWD And AFT, The AFT And Bulk Compartments Are Only Separated By A Curtain, So We Consider The AFT And Bulk As One Compartment.

• Each Cargo Compartment Is Divided Into Three Zones, If Smoke Is Detected In Any Of The Zones, A FIRE WARNING Is Triggered Identifying FWD or AFT Compartment.

• Warnings And Indications Of A CARGO FIRE

1. The FIRE Bell Sounds
2. The MASTER WARNING Lights Illuminates
3. An EICAS Warning Message FIRE CARGO (FWD or AFT), is displayed
4. The CARGO FIRE (FWD or AFT), light comes ON.

• (Pressing A MASTER WARNING Light Will Cancel The Warning Lights And Silence The Bell, But The Other Indications Remain Until The Fire Cargo Compartment Fire Is No Longer Detected).

• If The Smoke And Detection System Is Inoperative An EICAS Message DET FIRE CARGO (FWD or AFT) Is Displayed.

• There Are Five Extinguishing Bottles Installed To Fight A Cargo Compartment, And They Are Armed By Pushing The FWD OR AFT CARGO FIRE ARM Switch, In Which Case The ARMED Label Is Visible.

• Automatic And Manual Extinguishing are available in Flight, a Fire Warning will Automatically Arm And Activate The Extinguishing System, But Regardless of the automatic discharge feature, the procedure will direct the crew to push and hold the DISCH switch after arming the system.

The System may be armed and activated Manually by Pushing the FWD or AFT CARGO FIRE switch, and then Hold the CARGO FIRE DISCHARGE switch

System Activation

• If Activated In flight, Two Bottles Will Immediately Discharge To The Selected Cargo Compartment To Knock Down The Fire. After 15 Minutes Delay, the remaining Three Bottles Will Discharge At A Reduced Flow Rate To Provide A Continuing Fire Suppression.

Note: If The Airplane Lands Within 15 minutes, Only One Bottle Will Discharge At A Reduced Flow Rate To Provide Continuing Fire Suppression.

• On The Ground There Is No Automatic Activation of Extinguishing Bottles To The Cargo Compartments. It is Only Manually Activated By Pushing The CARGO FIRE DISCHARGE Switch. Three Extinguisher Bottles Discharge Simultaneously To The Selected Compartment, But The Third Bottle Discharges At Reduced Rate.-As Soon As The Discharge Is Initiated, And The First Two Bottles Begin To discharge, The Discharge Light Illuminates. After The Two Bottles Have Discharged An EICAS Message BOTTLE DISCH CARGO Displays.

Note: Ground Personal Are Not To Open The Cargo Doors Till All Passengers And Crew Are Off The Aircraft.

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Crew Rest Compartment

Equipped with a Smoke Detection System If Smoke Detected the appropriate EICAS Caution message is Displayed.-Only a Handheld Fire Extinguisher is available.

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Lavatory Smoke Detectors

• Equipped with a Single Smoke Detector

• If Smoke Is Detected, An Aural Alert Sounds In The Lavatory And In The Cabin.

• Indications

1. Lavatory Call Light Flashes
2. The Master Call Light At The Associated Attendant Station Illuminates
3. An EICAS Advisory Message SMOKE LAVATORY Is Displayed

• Each Lavatory has a small Fire Extinguisher Bottle that will automatically discharge into the waste container if a Fire or Excessive heat is detected, there is no Indication to the flight crew or cabin crew of the operation of the extinguishers.

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Related Bulletins

ENGINE FIRE SWITCH FAIL

Reason: Long Term Heating In the Fire Handle Locking Mechanism In Normal Operation

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Locked

The Engine Fire Switch Cannot Be Pulled

• Follow the Non-Normal Check list
• Fuel Control Switch CUTOFF closes the Fuel Spar Valve And Off Lines The Affected VFSG, Variable Frequency Starter Generator, When The Engine Speed Is Bellow Idle.
• Set the HYD ENG PRIMARY Pump Switch To OFF

LAND AS SOON AS POSSIBLE

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Unlocked

The Engine Fire Switch Can Be Pulled

• The Engine Fire Switch Can Be pulled And Is Not Protected.
• The Engine Fire Bottles Can Be Discharged.

Note: Flight Crew Do Not Test Engine Fire Switches, As It Can Increase Failure Rates. (Boeing Recommendation)

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