Final Flashcards
What is a Class A fire zone?
There are large quantities of air flow past regular arrangements of similarly shaped obstructions.
What are the two functions of a fire protection system ?
Detection, extinguishing.
What is a Class B fire zone?
Large quantities of air flowing past aerodynamically clean obstructions.
What is a Class C fire zone?
Relatively small quantities of air flow.
What is a Class D fire zone?
Little or no airflow
What is a Class X fire zone?
Large quantities of air flowing past regular arrangements if irregularly shaped obstructions and/or at irregular rates.
What does a zone determine?
The volume of extinguishing agent required.
What is an example of a class D fire zone?
Wheel wells and inside the wing
What is an example of a class C fire zone?
Engine accessory compartment
What is an example of a Class B fire zone?
Heat exchanger ducts, manifold shroud
What is a thermoswitch system?
Spot detector triggered by specific overheat temp.
Describe the operation of a fenwal system.
Electrical bimetallic switch mounted in stainless steel housing heats and expands, the contacts close to complete the warning circuit to power light/alarm.
What two metals are used in a thermocouple system?
Iron & constantan
Chromel and alumel
What is a continuous loop triggered by?
Specific overheat temp
What is an advantage of using continuous loop?
Provides more complete coverage.
Describe the construction of
The fenwal continuous loop system.
Single wire surrounded by ceramic beads wetted with eutlectic salts in an inconel tube
Describe the operation of a kidde continuous loop system.
Ceramic core changes resistance with temperature, allowing current to flow and activating the warning circuit.
What does a Lindbergh sensing element consist of?
A sealed, gas filled stainless steel tube.
What are three basic types of detectors?
Overheat
Rate of rise
Flame detectors
How are smoke detectors classified?
The principle of operation
What are the three classifications of smoke detectors?
Light refraction type
Ionization type
Solid state type
What concentration of carbon monoxide causes impairment?
.02%
Where are carbon monoxide detectors usually found ?
In the cockpit and cabin
Explain the operation of a radiation detector
Fire emits an infrared radiation that is sensed by the detector.
What is a class A fire?
Ordinary combustibles!
What is a class B fire?
Flammable liquids!
What is a Class C fire?
Energized electrical equipment!
What is a Class D fire?
Flammable metal!
What does the class of fire determine?
The type of agent required
What are the three requirements for fire?
Oxygen, fuel, heat.
What is the definition of fuel?
Something that will combine with oxygen in the presence of heat.
What is the definition of oxygen?
An element that readily combines with other substances.
What is heat?
The catalyst that accelerates the combining of oxygen and fuel.
What fires can water be used on?
Only class A
What fires can dry chemical powder be used on?
class ABC
What class fires are inert cold gas agents used on?
Abc
What class fires is specialized dry powder user on?
d
What are handheld portable extinguishers required by?
FAR 23.851, 135.155
What are unsuitable types of hand held extinguishers?
Co2, dry chemical.
HRD systems provide high rate of discharge through:
High pressurization
Short feed lines
Large discharge valves and outlets
What does a bottle transfer switch do?
Selects the second bottle which can then be discharged.
What does pressing the bottle discharge switch do?
Ignites the squib, breaks a frangible disk, and discharges the HrD bottle.
Why must special caution be taken with Fps maintenance?
Harsh environment , delicate construction, high pressure and explosive devices.
When inspecting Fps what things must be checked?
Security Cracked or broken wires or sections Abrasions Proper safety wiring Rubber grommets in place Dents and kinks Nuts, right type and torque Routing and proper support 8-12 in Operation check cO detectors should be inspected for discolouration and out of date
What could cause an intermittent alarm?
An intermittent short
What could cause the fire alarm and warning lights to occur when no fire or overheat condition exists?
A short, detector flaw,
What is the most common cause of false alarms?
Kinks or sharp bends in a sensing element
What is used to check sensing elements?
A mega ohm meter
What could cause the failure to obtain an alarm?
Defective test switch Defective control unit Lack of source voltage Inoperative indicator light An open in the sensing element or connecting wires.
Servicing and repair of the systems usually consists of what ?
Cleaning and replacement of components.
What things do you want to inspect when dealing with extinguishing systems?
Security of components Bottle pressure indication Squib date Leak test discharge tubing Wiring continuity Extinguishing system indicators
What does a discharged yellow disk mean?
Agent has been discharged through cockpit controls
What does a missing red disk indicate ?
Agent has been discharged as a result of over pressure/heat
How often must extinguishing bottles be removed and tested?
Five years
What is the extent of repair on extinguishing bottles?
Fluid line/electrical issues and replacement of components
