Fire Protection Flashcards
Describe the Engine Fire Detection System
Each engine has 2 fire loops A and B. The loop is temperature sensitive and routed throughout the nacelle. Data is sent to the Fire Detector Control Unit (FDCU) - decision maker for failure, fault, or fire.
Describe the Pylon Overheat Detection System
Each pylon are has 3 thermally sensitive switches installed adjacent to the bleed air ducting. If ambient temp within the pylon area rises above preset level, one or more of the switches will close and display a “PYLON HOT” CAS.
Describe the APU Fire Detection System
Has a single helium gas filled tube routed through the APU system. The loop is capable of discriminating between fires and faults. APU will auto shut down if a fire is sensed, except during testing
Pax and Tail Compartment Overheat Detection System
Thermally sensitive switches installed at various locations in pax and tail compartment areas. CAS displayed when an excessive temp is sensed:
LEER, REER, AEER, Fwd Floor, Left Aft Floor, Center Aft Floor, Right Aft Floor, Aft Equipment area (tail)
Describe the Engine Fire Extinguishing Sys
Armed any time the L/R ESS DC bus is powered. The sys has 2 identical single-shot fire extinguishing bottles referred to as LEFT and RIGHT.
Bottles contain Halon extinguishing agent under high pressure and are mounted in the tail.
A low pressure switch within each bottle will issue a CAS msg regardless of how the bottle was discharged - by crew (routing to engine cowling interior) or overpressure within bottle (into tail)
APU Fire Extinguishing Sys
Powered by the LEFT ESS DC bus (unable to extinguish if not powered).
Only LEFT bottle (#2) for APU.
Baggage Compartment Vent? (above baggage door)
When handle moved to VENT/SMOKE, the EXTERIOR baggage compartment door seal begins to depressurize and baggage air is vented outside. (If the INTERIOR baggage door is opened, cabin air will also be vented overboard)
If the interior door stays shut, pressure differential develops between baggage comartment and cabin. The valve sensing port senses pressure, if too high the cabin vent valve will close and air will stop flowing into the baggage compartment.
On-board Fire Extinguishers
Halon: Behind copilot seat and seat 1. Type A, B, and C fires
Water: Behind Seat 2
