ATR 42 Model : 400/500
GENERAL
FIRE PROTECTION
P 1
NOV 98
001
1.08
.
10
10.1 DESCRIPTION
The fire protection system is provided in order to ensure :
- Detection for :
•
each engine fire
•
right nacelle overheat (on ground only)
•
each cargo compartment and toilets smoke
•
avionics compartment smoke
- Extinguishing for :
•
each engine
•
cockpit, cabin and each cargo compartment
•
toilets waste bin
ENGINE FIRE DETECTION SYSTEM
Each engine is equipped with a fire detection system which consists of :
- Two identical detection loops (A and B) mounted in parallel.
- A fire detection control unit.
The detection principle is based on the variation of resistance and capacitance of the
detection cable (fire signal). If there is only a change in resistance, associated loop
will be declared failed by the fire detection control unit (fault signal).
Red ENG. FIRE illuminates on CAP in case of :
- Fire signal detected by both loops A and B or,
- Fire signal detected by one of the 2 loops if the other one is selected OFF.
RIGHT NACELLE OVERHEAT DETECTION SYSTEM
Right nacelle is equipped with an overheat detector. When right nacelle temperature
exceeds 170
°
C, NAC2 OVHT red alarm is triggered on CAP, and the CCAS is activated.
CARGO AND TOILETS SMOKE DETECTION SYSTEM
Forward cargo and after cargo are each equipped with one optical smoke detector.
Ambient transmittance is monitored by reflection measurement.
Toilets are equipped wih one photoelectric smoke detector.
In case of smoke detection, SMOKE" signal is sent to CCAS through the MFC.
AA
R
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