1. General
A. Fire protection consists of fire extinguishing and fire/overheat
detection.
B. The detection systems warn of fire or overheat in each engine, auxiliary
power unit (APU), main wheel well, wings, lower aft body and lavatories
(airplanes with lavatory smoke detection system). Lights on the engine
and APU fire control module, master warning lights on the lightshield
module, and an alarm bell provide fire indication. On some airplanes,
there is a light on the overhead panel in the control cabin which
provides fire indication. Additional indications for the APU are a fire
warning light on APU ground control panel and a warning horn in the right
main wheel well. Lights on the air conditioning module and master
caution lights on the lightshield module provide wing/body overheat
indication. Lights on the light shield module and on the overhead panel
provide lavatory smoke indication (airplanes with lavatory smoke
detection system).
C. The extinguishing systems are a fixed engine fire extinguishing system, a
fixed APU fire extinguishing system, a fixed lavatory fire extinguishing
system, and portable fire extinguishers.
(1) The fixed engine fire extinguishing system consists of two fire
extinguisher bottles, providing two-shot extinguishing at either
engine. The bottles are connected to each engine by manifolds and
tubing. A discharge switch for each engine is on the engine and APU
fire control module.
(2) The fixed APU fire extinguishing system consists of an extinguisher
bottle connected by tubing to the APU shroud. The APU discharge
switches are on the engine and APU fire control module and on the
APU ground control panel.
(3) The fixed lavatory fire extinguishing system consists of a heat
activated fire extinguisher bottle in each lavatory to extinguish
fires under the sink counter and in the towel chute.
(4) Portable fire extinguishers are located in various positions in the
crew and passenger cabins. They provide fire extinguishing
capability in these cabins and other areas accessible from them.
2. Engine and APU Fire Control Module
A. The engine and APU fire control module P8-1 contains components to
monitor the fire and overheat detection systems and to control and test
the fire extinguishing system. The engine and APU fire control module is
on the control stand aft electronic control panel P8.
B. The front of the module contains the following components for
extinguishing and detection: fire switch handles with fire warning
lights for each engine and the APU, discharge lights for each engine and
APU, overheat lights for each engine, wheel well overheat light, engine
detector fault light, fire/overheat detector selector switch for each
engine, an APU detector inoperative light, a bell cutout switch, test
switches, and three fire extinguisher test lights. Master caution lights
control circuits and fire extinguisher bottle test circuits are on cards
in the module.
3. Lightshield Module
A. The lightshield module P7 contains master fire warning, master caution,
and annunciator lights.
4. APU Ground Control Panel
A. The APU ground control panel P28 contains a fire warning light, a handle
to arm the APU fire extinguishing system, and bottle discharge and bell
cutout switches. The panel is on the aft bulkhead of the right main
wheel well.
5. Air Conditioning Module
A. The air conditioning module P5-10 on the forward overhead panel has
overheat lights and a test switch for the wing and lower aft body
detection system.
