Learjet 20 Series Pilot Training Manual page 164

ARMED ARMED
*BLEED-
AIR VALVE
LH NACELLE
FUEL SHUTOFF
VALVE
HYDRAULIC
SHUTOFF VALVE
Figure 8-4.
valve as well. A small, red shutoff valve light,
commonly called a "pinhead light," will illu-
minate to indicate the FIRE warning light has
been depressed. Power is also applied to arm the
respective amber ARMED lights (Figure 8-4).
Depressing an illuminated ARMED light mo-
mentarily applies DC power to an explosive
cartridge, which discharges the contents of a
bottle to the selected engine. Depressing the
adjacent ARMED light fires the remaining
bottle to the same engine. Depressing the FIRE
warning light a second time disarms the sys-
tem (ARMED lights go out), opens the hy-
d r a u l i c a n d f u e l s h u t o ff va l v e s , a n d
extinguishes the pinhead light.
8-4
LEARJET 20 SERIES PILOT TRAINING MANUAL
SHUTOFF VALVE (PINHEAD) LIGHT
FIRE
PRESSURE GAGE
LH
CONTAINER
RELIEF VALVE
THERMAL
DISCHARGE INDICATOR
Engine Fire-Extinguishing System (Airplanes with
Glareshield Warning Lights)
FOR TRAINING PURPOSES ONLY
FIRE
PRESSURE GAGE
TWO-WAY
CHECK
CONTAINER
VALVES
RELIEF VALVE
MANUAL
DISCHARGE INDICATOR
Airplanes Without Glareshield
Warning Lights
Opening the red guard and actuating a FIRE-
WALL SHUTOFF switch (LH or RH) selects
the engine to which fire-extinguishing agent
is to be applied. It also applies 28 VDC to
close the hydraulic and fuel shutoff valves
(Figure 8-5) and arms the No. 1 and No. 2 dis-
charge switches.
Depressing the No. 1 discharge switch fires
a bottle to the selected engine. If a second
charge of extinguishing agent is desired, de-
pressing the No. 2 discharge switch fires the
r e m a i n i n g b o t t l e t o t h e s a m e e n g i n e .
Returning the guarded FIREWALL SHUT-
OFF switch to the off position opens the hy-
draulic and fuel shutoff valves and disarms
the fire-extinguishing system.
FlightSafety
international
*SNS 24-350 AND SUBSEQUENT AND
25-227 AND SUBSEQUENT
ARMED
ARMED
FUEL SHUTOFF
VALVE
*BLEED-
AIR VALVE
RH
RH NACELLE
HYDRAULIC
SHUTOFF VALVE
LEGEND
ENGINE EXTINGUISHING
MANUAL DISCHARGE
THERMAL DISCHARGE