Fire Protection Flashcards
What powers engine and APU overheat and fire detection?
Battery Bus
What powers the engine and APU overheat and fire extinguishing?
Hot battery bus
How are Fire Detection Loop failures indicated?
During Overheat/Fire test, a bad loop will be indicated:
-Engine: Fire Switch/Overheat lights extinguished. FAULT light illuminated (isolated by OVHT switch to A or B for engines. Good loop provides normal test. Dual loop)
-APU: Fire Switch extinguished. APU DET INOP light illuminated. Single loop
-wheel well: wheel well (red) light extinguished. single loop
Engine: FAULT (Amber) light illuminates with OVHT DET switch
-NORMAL, if both loops fail
-A or B, and selected loop fail
-A or B (operative loop) with other loop inop and selected loop fails
*no indication of single loop failure
APU: APU DET INOP (amber) light
Wheel well: thermistor type. Different from engines. Failed/broken loop can still detect fire. Senses from each end of loop.
*if short circuits, indications same as real alarm
How is an engine or APU fire bottle discharged?
- Pulling the associated Fire Switch up arms the discharge squib on extinguisher bottle
- Rotating the fire switch electronically fires squib and discharges extinguishing agent to related engine or APU
*2 bottles for engines. Selected fire switch can dish charge both bottles to selected engine of rotated both directions.
*APU has one bottle. Discharged by rotating either way
Which systems are affected by pulling an Engine Fire Switch?
-Closes:
—Engine fuel shutoff and spar fuel shutoff valve
—engine bleed air valve. Results in no wing anti ice affected side. Pack valve closes
—hydraulic fluid shutoff valve (engine hyd low press light deactivated)
-trips gen control relay and breaker
-disables related thrust reverser
-arms one squib each extinguisher bottle
-allows fire switch to be rotated
What are the components of the APU Fire Detection and Extinguishing system?
Single fire detection loop
APU fire switch
Single extinguisher bottle
APU BOTTLE DISCHARGED light
What are the effects of pulling an APU Fire Switch up?
-Provides backup for the automatic shutdown feature
-deactivated the fuel solenoid and closes the APU shutoff valve
-closes APU bleed air valve
-closes APU air inlet door
-trips APU generator control relay and breaker
-allows fire switch to be rotated for discharge
-arms APU extinguisher bottle squib
Will the APU fire bottle discharge automatically for an APU fire?
No
Where is the APU fire ground control panel?
Main wheel well
Aft side, aircraft right
Does the main wheel well have a fire extinguishing system?
No
How can the Fire Warning Bell be silenced?
Pushing either of the 2 Master Fire Warn lights (glare shield by master caution and system annunciators)
Fire warning bell cutout switch (top center of Overheat/Fire Protection Panel by Fire Switches)
What does placing the TEST switch in the Fire Protection Panel to FAULT/INOP and FIRE/OVHT test?
FAULT/INOP
-tests engine and APU fault detection circuitry and related flight deck indicators
OVHT/FIRE
-tests engine and APU overheat and fire detection circuitry and related flight deck indicators. Includes fire detection loops on both engines, APU, and main wheel well
How is a Lower Cargo Compartment fire detected?
Smoke detectors (fwd/aft cargo) powered by DC Bus 1 and 2
Dual loop. Normally both loops must detect
Failure in 1 loop auto converts to single loop
*if smoke detected pressurization controller descends cabin at -750 fpm to reach max diff press of 9.1 PSID. Helps prevent cabin smoke penetration. Inhibited in ground.
*dual bottle over 180 min fire suppression
-1st bottle discharge and start 60 min timer
-then, 2nd bottle slow discharge after timer to provide total of 195 min suppression (extra 15 min for missed approach, landing, and evac)
*single bottle just discharges bottle. 75 min of suppression (60 min flight time plus 15 extra as stated above)
What does an illuminated DETECTOR FAULT (amber) light indicate on the Cargo Fire panel?
With the DET SELECT switches in normal, indicates one or more detectors in the loops have failed
