Fire Protection Flashcards
Overheat Detector OVHT DET switch
Normal- both loop A and B are active
A- detection loop A active
B- detection loop B active
Fire warning BELL CUTOUT switch
When you push:
- extinguishes the master FIRE WARN lights
- silences the fire warning bell
- Silences the remote APU fire warning horn (ground only)
- resets system for additional warnings
EXT TEST switch
1 or 2- tests bottle discharge circuit continuity for all three extinguisher bottles
FAULT/INOP and OVHT/FIRE switch
FAULT/INOP- tests fault detection circuits for both engines and APU
OVHT/FIRE- tests overheat and fire detection loops on engines, APU, and wheel well fire detector
APU FIRE SWITCH (RED)
Red:
- indicates APU fire
- Unlocks APU fire switch
What happens when you pull the APU fire switch? And then rotate it?
- arms the APU extinguisher circuit
- Closes fuel SOV, APU bleed air valve, APU inlet door
- trips generator control relay and breaker
- Allows APU fire switch to rotate
When you rotate it, it discharges the APU fire bottle
Engine Fire Switch (red)
it is mechanically locked if no fire signal
- indicates fire in related engine
2. unlocks related engine fire switch
What happens when you pull the engine fire switch?
- Arms one squib on each engine fire extinguisher
- closes fuel SOV
- closes hydraulic SOV
- closes engine bleed air valve
- disables thrust reverser
- trips generator control relay and breaker
- deactivates engine driven hydraulic pressure LOW PRESSURE light
- allows engine fire switch to rotate
Fire Switch Override
Push- unlocks the engine fire switch
ENG OVERHEAT light(amber)
indicates overheat in related engine
FAULT light (amber) With overheat detector switch in NORMAL or overheat detector switch in A or B
in NORMAL:
indicates both detector loops for an engine have failed
in detector switch in A or B- indicates the selected loop for an engine has failed
Wheel WELL Fire warning light (red)
indicates fire in main gear wheel well
the FIRE WARN light and bell also sounds
Engine BOTTLE DISCHARGE light (amber)
related fire extinguisher bottle has discharged
APU DET INOP light (amber)
APU detector loop has failed
APU BOTTLE DISCHARGE light (amber)
APU extinguisher bottle has discharged
EXT TEST lights (green)
EXT switch positioned to 1 or 2 and circuit continuity is normal
EXT Test lights (green) for cargo
indicates the the cargo fire TEST switch is pushed and fire bottle discharge squib circuit continuity is normal
cargo DETECT SELECT Switches (NORM, A, B)
NORM- detection loop A and B active
A- loop A active
B- loop B active
Cargo Fire ARMED Switches (momentary action) (MAIN, FWD, ARMED)
PUSH-
MAIN ARMED- commands pack to low flow
FWD ARMED- extinguisher armed for FWD compartment
AFT ARMED- extinguisher armed for AFT cargo compartment
Cargo Fire (MAIN FWD AFT) Warning lights (red)
- at least one detector in each loop detects smoke
or - with power failed in one loop, at least one detector on the remaining loop detects smoke
DETECTOR FAULT light (amber) (cargo)
both loops in one or more cargo compartments failed
Cargo Fire DEPR/DISCH Switch (momentary action)(amber)
for a/c with one extinguisher
for a/c with two extinguishers
Push:
-if main cargo system armed, closes air distribution SOV and opens mix manifold exhaust valve
for a/c with one extinguisher bottle:
PUSH- if forward or aft cargo system is armed, discharges the bottle
for a/c with two extinguisher bottles:
Push- if forward or aft cargo system is armed, discharges first bottle
Cargo Fire DEPR light (amber)
the MAIN cargo deck suppression system is activated, FWD and AFT
MAIN DECK SHUTOFF VALVES are closed and MIX MANIFOLD
EXHAUST VALVE is open.
Cargo Fire Bottle Discharge (DISCH) Light (amber)
indicates an extinguisher bottle has discharged
Cargo Fire TEST switch
Push- tests circuits for forward, aft, and main cargo fire detector loops and suppression system
Master FIre Warning (FIRE WARN) lights (red)
what happens when you push it?
Indicates a fire warning or system test in engine, APU, main gear wheel well, or cargo compartment.
Accompanied by:
-fire warning bell
-if on ground, remote APU fire warnning horn sounds
PUSH-
- extinguished the FIRE WARN lights
- silences the warning bell
- silences the remote APU fire warning horn
- resets system for additional warnings
How many overheat/fire detector loops in each engine? Normally, must both detect overheat or fire condition to cause an alert?
2, Yes
What will happen if one engine fire loop fails with OVHT DET switch in NORMAL? Will there be a flight deck indication?
If one loop fails, the loop is deselected and the remaining loop functions alone. There will be no indication unless both loops fail on an engine (FAULT light)
If only fire loop A or B is selected on the OVHT DET switch, what happens?
The system operates as a single system and the non-selected loop is not monitored.
How many engine fire bottles?
2 bottles which can be discharged into either engine
When you rotate the engine fire switch, what happens?
It electrically fires a squib, which discharges the agent into the related engine
Engine Fire protection consists of these two systems? what are they each powered by?
- engine overheat and fire detection (battery bus)
2. engine fire extinguishing (hot battery bus)
APU fire protection consists of these two systems:
what are they powered by?
- APU fire detection (battery bus)
2. APU fire extinguishing (hot battery bus)
How many fire loops on the APU?
1
If the APU fire loop fails, what will illuminate?
APU DET INOP light
Indications of APU fire:
- Fire bell
- Master FIRE WARN lights (2)
- APU fire switch illuminates
- APU auto shuts down
- Wheel well APU fire warning horn sounds (on ground), and wheel well APU fire warning light flashes
What does APU fire extinguishing consist of?
- fire bottle
- APU fire switch
- APU bottle discharge light
- EXT TEST switch
What does the APU ground control panel consist of and location.
Located in right main wheel well
- APU fire warning light and horn
- APU BOTTLE DISCHARGE switch
- APU fire control handle
- APU HORN CUTOUT switch
Main wheel fire protection is only detection powered by:
AC transfer bus 2 and battery bus
How many fire loops for the main wheel well fire detection?
1
Indications of a main wheel well fire:
- fire warning bell
- Master FIRE WARN lights illuminate (2)
- WHEEL WELL fire warning light illuminates
Cargo Compartment Fire Protection consists of these two systems:
Powered by?
- Cargo Compartment smoke detection powered by DC bus 1 and DC bus 2
- cargo compartment fire suppression powered by hot battery bus
Instead of fire loops, each cargo compartment have smoke detectors in a loop configuration. How many loops?
2
If there is a power failure in one smoke detector loop in a cargo compartment, what happens?
the system automatically converts to single loop detection
Indications of cargo compartment fire:
- Fire warning bell
- Master FIRE WARN lights illuminate (2)
- MAIN/FWD/AFT cargo fire warning light illuminates
in an aircraft with a single cargo fire extinguisher bottle:
after arming the system by pushing ARMED switch, what happens when you press the DISCH switch?
It discharges the bottle contents into the selected compartment. the DISCH switch illuminates once the bottle is discharged (can take up to 30 seconds)
in an aircraft with two cargo fire extinguisher bottles:
after arming the system by pushing ARMED switch, what happens when you press DISCH switch?
Can you disable discharge of the second bottle?
the first bottle is immediately discharged into the selected compartment. The second bottle is metered to discharge at a reduced flow into the selected compartment.
Discharge of the second bottle can be disabled if you disarm the system. On landing, the second bottle discharge is inhibited
How is main deck cargo fire suppression accomplished?
When you press ARMED switch, packs go to low flow and then when you press DEPR/DISCH switch, the air distribution shutoff valves close. The aircraft gradually depressurizes and thereby depletes the oxygen required for combustion
DEPR light illuminates when distribution valves are closed
What are indications for the FAULT/INOP test? What are you testing?
-this test tests fault detection circuits for the engines and APU indications: -Master caution lights (2) -OVHT/DET annunciator light -FAULT light illuminates -APU DET INOP light illuminates
What does the OVHT/FIRE test for? What are the indications?
This test tests the overheat and fire detection loops on both engines, APU, and fire detector in wheel well.
Indications:
1. fire warning bell
2. Master Fire WARN lights (2)
3. MASTER CAUTION lights (2)
4. OVHT/DET annunciator (1)
5. Both engine fire switches illuminate (2)
6. APU Fire switch illuminates (1)
7. Both ENG OVERHEAT light illuminates (2)
8. WHEEL WELL fire warning light illuminates (1) if AC power available
9. on ground, wheel well APU fire horn sounds and warning light flashes
The cargo fire TEST switch does what?
a test signal is sent to forward, aft, and main fire detector loops, which verifies power availability and circuit continuity for the extinguisher bottle squibs. All lights except DETECTOR FAULT light should illuminate
