detector and the extinguisher functions. Closure of the
operable on the ground only. The automatic ex-
access door rearms the system. An APU TEST switch
tinguisher system is a dual channel system energized
is mounted adjacent to the four nacelle test switches on
from the detector signal. The primary channel fires a
the overhead panel in the cockpit. Upon setting the
dual cartridge squib by means of a limit switch that
APU TEST switch, the fire warning lights will come on
actuates when the APU exhaust door is fully closed
and the horn will sound, indicating the system is
(approximately 15 seconds is required for exhaust door
working properly.
closure). If the primary channel fails to operate, the
secondary channel, through a time delay relay, fires
Q5-31.
Under normal atmospheric pressure and
the cartridge in approximately 20 seconds. The
temperature, describe the characteristics of
glareshield-mounted MAN REL AUX PWR UNIT
CF3BR.
EXTINGUISHER switch may be used to energize both
Q5-32.
How many independent fire-extinguishing
fire extinguisher channels and thus bypass the detector
systems does a P-3 aircraft use?
system. In addition to operating the warning light,
horns, and extinguisher automatic discharge, the
Q5-33.
List the different ports for a transfer check
detector system also provides output signals to
valve.
accomplish complete electrical shutdown of the APU.
Q5-34.
What is the internal volume of a P-3
This includes intake and exhaust door closure, fuel
fire-extinguishing container?
valves closed, fuel pumps off, and ignition circuit
deenergized. The fire detector is armed from the
Q5-35.
Describe the procedures if a fire is indicated
aircraft ac-dc distribution system at all times that the
in no. 3 engine nacelle.
aircraft generator or ground power is available. In the
Q5-36.
Describe the purpose of an auxiliary power
absence of ac power, the detector is armed from the
unit.
aircraft battery. The detector is disarmed when the
battery is disconnected. A maintenance switch
Q5-37.
What is/are the indication(s) given if a fire is
accessible through an access door may disarm the
present in the APU?
Figure 5-25.--Waveguide pressurization system.
5-22
