b. The fire control handles used to arm the
extinguisher system are centrally located on the pilot's
instrument panel immediately below the glareshield.
These controls receive power from the hot battery bus.
The fire detection system will indicate an engine fire by
illuminating the master fault warning light on the
copilot's glareshield and the respective #1 or #2 FIRE
PULL lights in the fire control handles. Pulling the fire
control handle will electrically arm the extinguisher
system and close the firewall shutoff valve for that
particular engine. This will cause the red light in the
PUSH TO EXTINGUISH switch and the respective red
#1 or #2 FUEL PRESS light in the warning
annunciator panel to illuminate. Pressing the lens of
the PUSH TO EXTINGUISH switch, after lifting one
side of its spring-loaded clear plastic guard, will fire the
squib, expelling all of the agent in the cylinder at one
time. The respective yellow caution light, placarded #1
or #2 EXTGH DISCH, on the caution/advisory
annunciator panel and the MASTER CAUTION lights
illuminated, regardless of the master switch position,
until the squib is replaced. The MASTER CAUTION
light may be reset.
c. A test switch, placarded FIRE PROTECTION
TEST, is located on the copilot's subpanel, Figures 2-6
and 2-8. The test functions, placarded EXTGH #1 / #2
C D T1 or EXT LEFT / RIGHT T2 , provide a test of
the pyrotechnic cartridge circuitry. During preflight, the
pilot should move the test switch through the two
positions and verify the illumination of the green
SQUIB OK light on the PUSH TO EXTINGUISH switch
and the corresponding yellow #1 or #2 EXTGH DISCH
light on the caution/advisory annunciator panel.
d. A gauge, calibrated in psi, is mounted on
each supply cylinder for determining the level of
charge and should be checked during preflight. Refer
to Table 2-2.
2-33. OIL SUPPLY SYSTEM.
a. The engine oil tank is integrated with the air-
inlet casting located forward of the accessory gearbox.
Oil for propeller operation, lubrication of the reduction
gearbox, and engine bearings is supplied through an
external line from the high-pressure pump. Two
scavenge lines return oil to the tank from the propeller
reduction gearbox. A non-congealing external oil
cooler keeps the engine oil temperature within the
operating limits. The capacity of each engine oil tank
is 2.3 U.S. gallons. The total system capacity for each
engine, which includes the oil tank, oil cooler, lines,
etc., is 3.5 U.S. gallons. A dipstick attached to the oil
filler cap indicates the oil level. Oil grade, specification
and servicing points, are described in Section XII,
b. The oil system of each engine is coupled into
a heat exchanger unit (radiator) of fin-and-tube design.
These exchanger units are the only airframe mounted
part of the oil system and are attached to the nacelles
below the engine air intake. Each heat exchanger
incorporates a thermal bypass, which assists in
maintaining oil at the proper temperature range for
2-34. ENGINE CHIP DETECTION SYSTEM.
A magnetic chip detector is installed in the
bottom of each engine nose gearbox to warn the pilot
of oil contamination and possible engine failure. The
sensor is an electrically insulated gap immersed in the
oil functioning as a normally open switch. If a large
metal clip or a mass of small particles bridge the
detector gap, a circuit is completed sending a signal to
illuminate an annunciator panel red indicator light,
placarded #1 CHIP DETR or #2 CHIP DETR, Figure
2-17, Sheets 2 and 3 D2 T1 or #1 CHIP DETECT or
#2 CHIP DETECT, Figure 2-17, Sheets 1 and 4
C D1 T2 , and the MASTER WARNING light. Chip
detector circuits are protected by two 5-ampere circuit
breakers, placarded CHIP DETR #1 and CHIP DETR
#2, on the overhead circuit breaker panel, Figure 2-16.
Table 2-2. Engine Fire Extinguisher Gauge Pressure