Learjet 60 - ENG FIRE PULL Handle and ENG EXT ARMED Lights; Fire Extinguisher Discharge Indicators

Pilot's Manual
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Lea4et 60
content
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either
or both extinguishing
agent
containers
to
either en-
gine nacelle . Two-way check
valves
are installed to prevent extinguish-
ing agent flow between containers
.
The extinguishing agent, Halon
1301 (bromotrifluoromethane [CF315r]), is stored under pressure in the
extinguisher containers and a pressure gage on each container is visible
ide the tailcone . Halan 1301 is non-toxic at
normal tempera-
is
non-corrosive . As Halon 1301 is non-corrosive, no special
cleaning of the engine or nacelle area is required in the event the system
has been used . The system operates on 28 VDC supplied through the
75-amp L and R FIRE EXT circuit breakers on the pilot's and copilot"s
circuit
breaker panels respectively . The fire extinguishing system is op-
erative during EMER
BUS
mode .
ENG FIRE PULL HANDLE AND
ENG
E)iT
ARMED LIGHTS
e engine ire extinguishing system is operated through the ENG
FIRE PULL T-handles and
the ENG EXT ARMED lights located
on ei-
ther end of the glaresbield annunciator panel . The ENG EXT ARMED
lights are combination light switches . When the ENG FIRE PULL
T,handle is pulled, the associated engine fuel, hydraulic, and bleed-air
shutoff valves will close to isolate the affected engine . On aircraft WNW
and subsequent &prior
aircraft
modified by SB 60-78-5 (Installation of Thrust
rHydraulic Control Relay Box), the associated thrust reverses iso-
lation valve will also close, shutting off hydraulic fluid to the associated
thrust reverses . A solenoid valve in the HFCU shuts
off fuel to the en
gine causing immediate shutdown,
and both ENG EXT ARMED lights
will illuminate . Illumination of the ENG EXT ARMED lights indicates
at the fire extinguishing system is armed . Depressing an illuminated
ENG EXT ARMED light will discharge the contents of an extinguisher
into the affected
engine nacelle . Depressing the second
ENG EEXT
ARMED light will discharge
the contents of the other extinguisher bot-
tle into the affected
nacelle
.
FIRE EXTINGUISHER DISCH RGE INDICATORS
TWo disk-type indicators are
flush-mounted
in the fuselage under the
left
engine pylon . If due contents of either or both containers have been
discharged
into
the engine nacelles, the 'yellow disk will be ruptured . If
the contents of either or both
containers have been discharged over-
board
as the result of an overheat condition causing excessive pressure
within the containers, the red disk will be ruptured . If both disks are in-
tact, the system has not been discharged . The indicators are readily
ac-
cessible for visual inspection and must be checked for condition prior
to each flight .
200
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PM-123
Ownge 4