Specifications

SECTION II
AIRPLANE AND SYSTEMS
MODEL 560
FIRE PROTECTION
Engine fire detection consists of a closed-loop sensing system and detector control unit which
illuminates the respective red ENG FIRE warning light on the cockpit glare shield if a fire or overheat
condition is present. The warning light, under a transparent, spring-loaded guard, also serves as a firewall
shutoff switch.
Lifting the guard and depressing the warning light simultaneously closes the respective firewall fuel
and hydraulic valves, de-energizes the starter/generator and arms the two freon extinguishing bottles.
Firewall shutoff and extinguisher arming are indicated by illumination of the respective LO FUEL PRESS, LO
HYD FLOW, F/W SHUTOFF and GEN OFF annunciator panel lights and both white BOTTLE ARMED lights.
Once armed, either bottle may be discharged to the selected engine by pushing the BOTTLE ARMED
light. The light will go out as the light is pushed. System plumbing is such that both bottles can be directed
to the same engine if necessary.
Function of the lights and continuity of the sensor and detector control units is checked by placing the
rotary TEST selector in the FIRE WARN position and observing illumination of both red lights. Depressing
either fire light will then illuminate both BOTTLE ARMED lights. Since the BOTTLE ARMED lights will come
on each time the system is tested or initially activated regardless of freon quantity, it is necessary to check
proper bottle servicing on the sight gauges in the tailcone compartment during preflight inspection.
The fire detection system is equipped with an amber FIRE DET SYS annunciator light on the
annunciator panel. If the fire detection system becomes inoperative due to lack of continuity (an open
circuit) in the closed loop sensor, the annunciator will illuminate.
All test, detection and extinguishing features are electrically powered from the main Direct Current
(DC) buses requiring either external power, the battery switch in BATT, or a generator on the line for
operation.
Figure 2-7 Fire Detection Indicating Light
Figure 2-8 Engine Fire Extinguishing System
I 2-14 Configuration AA 56OMB-01