Fire Protection Flashcards
Fire detection and protection is provided for:
- Engines
- APU
- Cargo compartments
- Lavatories
Only smoke detection is provided for the avionics ventilation system.
What is the purpose of the FDU?
The Fire Detection Unit (FDU) generates a fire warning if (for both engines and APU):
* Both engine fire detection loops detect a fire
* One loop has failed and the remaining loop detects a fire
* Both loops have failed within 5 seconds of each other
What occurs when a FIRE pb is released?
When the FIRE pb is released, the following actions occur for the respective engine:
* The CRC is silenced
* The hydraulic fire valve closes preventing the circulation of hydraulic fluid in the are of the fire
* The low pressure engine fuel valve closes
* The respective electrical generator deactivates
* The respective pack flow control valve is electrically signaled to close
* The respective engine bleed valve closes
* The engines FADEC is unpowered
* Both fire bottle squibs arm
What occurs when the APU FIRE pb is released?
Pressing the APU FIRE pb causes the following to occur:
* The CRC is silenced
* The low pressure valve closes and the APU fuel pump deactivates
* The APU generator is deactivated
* The APU bleed valve closes which also closes the cross bleed valve
* The squib is armed for the APU halon bottle
* The APU shuts down
What indication is there if the APU fire bottle is charged?
A red disk located on the left rear of the fuselage to provide an indication of the APU fire bottle.
What are the APU fire test indications while on battery power?
The only APU fire test indications while on battery power are:
* APU FIRE pb illuminates
* SQUIB and DISCH lights illuminate
The automatic shutdown of the APU on ground may occur if the Flight Crew performs this test for more than 3 seconds
Describe the cargo fire detection and protection system.
The cargo smoke detectors are ionization type detectors and sense smoke particles, not heat. The forward cargo compartment has one ceiling cavity and the aft cargo compartment has two ceiling cavities, each cavity has two smoke detectors. The forward and aft cargo compartments share a single fire bottle.
What occurs if smoke is detected in the aft cargo compartment?
If smoke is detected in the aft compartment:
* The inlet and outlet isolation valves close
* The extraction fan stops
What is the SDCU?
A dual channel Smoke Detection Control Unit (SDCU), receives signals from the detectors and activates flight deck warnings when smoke is sensed.
When does the SCSU generate smoke warnings?
Cargo smoke warnings will be generated if:
* Excessive particles are detected by both detectors in a ceiling cavity
* One detector is inoperative and the other sense smoke
Describe how a test of the cargo fire protection system is accomplished.
To perform the test of the cargo fire protection system, you must press and hold the TEST pb for approximately 3 seconds. Both SDCU channels are tested separately, therefore a short pause will occur after the first test completes before the second channel tests.
Describe the lavatory fire detection and protection system.
The lavatory smoke detectors are ionizing types that sense smoke, located in the air extraction ducts of each lavatory. These detectors feed information to the Smoke Detection Function (SDF) of the Cabin Intercommunication Data System (CIDS). On some aircraft, the smoke detectors supply information to the SDCU.
The only indication of a lavatory smoke detection in the flight deck is an ECAM warning. The flight attendants are alerted in the cabin to the presence and location of lavatory smoke.
Each lavatory cabinet trash bin contains a self-contained fire detection and protection unit. A small halon fire bottle will discharge automatically in response to a sudden temperature rise. There is no flight deck or cabin indication that this halon bottle has discharged.
What is the purpose of the AEVC?
The smoke detector in the avionics compartment is connected to the Avionics Equipment Ventilation Controller (AEVC). The AEVC provides notification of smoke sensed within the avionics ventilation system.
What occurs if an ENG FIRE pb is released?
The Pilot pushes it to release it. It pops out, sending an electrical signal that performs the following for the corresponding engine:
* Silences the aural fire warning
* Arms the fire extinguisher squibs
* Closes the low-pressure fuel valve
* Closes the hydraulic fire shut off valve
* Closes the engine bleed valve
* Closes the pack flow control valve
* Cuts off the FADEC power supply
* Deactivates the IDG
When do the DISCH lights illuminate?
DISCH lights up amber when its fire extinguisher bottle has lost pressure
