11.8 Fire Protection * Flashcards
What is fitted in large areas and where the fire source is not known?
Smoke detectors
What is used in engines, APU, wheel well and hot air ducts for overheat detection?
Temperature sensitive detectors
What type of switch is the spot sensor?
Bi-metallic type switch
What are the 2 types of continuous loops for fire detection?
- Semi conductor loop
- Pneumatic pressure loop
What type of sensor is always on the engine fire detection system?
Dual continuous loop
What types of continuous loops are found on engines?
Both
What is the local warning of a fire detection system?
Red light inside a switch
What type of system do all essential fire warning systems use?
Dual loop systems
When is a fire warning triggered in a dual loop system?
If both sensors detect fire at same time
What is the ground warning in the APU fire detection system?
- if cockpit empty
- in nose or main wheel well area
- red light flashes and warning horn sounds
What are the 2 types of sensors in the pneumatic duct leak detection system?
- Spot sensor
- Semiconductor continuous loop
What is a disadvantage of the bi-metallic sensor system?
Control unit cannot detect a fault condition of this sensor
Where does the warning for a pneumatic dict leak appear?
Pneumatic or air conditioning panel
⚠️Class A (baggage compartment/wardrobe - accessible )
❌ fire detection system
❌ extinguishing system
⚠️Class B (lower or upper deck cargo compartment - accessible )
✅ fire detection system
❌ extinguishing system
⚠️Class C (lower or upper deck cargo compartment - not accessible)
✅ fire detection system
✅ extinguishing system
⚠️Class D (lower deck cargo compartment - small amount or no ventilation)
(Not required until 2003)
✅ fire detection system
✅ extinguishing system
Class E (cargo compartment in a freighter aircraft)
✅ fire detection system
❌ extinguishing system
How is the central warning cancelled on the ECAM or EICAS display?
Pressing the master warning light
⚠️What are the manufacturers names for semiconductor loops?
Kidde, Graviner, Edison or Fenwal
What are the 2 types of smoke detectors?
- optical system
- ionization type
How do semiconductor loops work?
Decreases electrical resistance with increasing temperature
How do pneumatic pressure loops work?
As gas increases with temperature it operates a pressure switch
⚠️How does the kidde, Fenwal, Graviner or Edison type conductors works?
Have a negative temperature coefficient (NTC)
How many internal wires does kidde manufacture have?
2
How many internal wires does Fenwal, Grabiner or Edison manufacturers have?
1
⚠️What happens when resistance of an area decreases below 500ohms?
Alarm is triggered
⚠️What is the normal resistance?
Between 1ohms for long loops and 10ohms for short loops
What is the minimum radius for loop installation?
No less than 25.4mm
What is the maximum bend for loop installation?
No more than 3.2mm
How does ionization type smoke detector work?
Clean air has light molecules, smoke molecules are heavier
⚠️What are the 2 types of halon extinguishers?
1301 (installed)
1211 (portable -least toxic)
How can you check a portable fire extinguisher hasn’t been used before?
- pressure gauge in green band
- safety pin installed
What is the installed fire extinguisher pressurised by, what psi, what temp?
Nitrogen, 600psi, 20*c
What weight are cargo compartment fire extinguishers?
20kg
What weight are engine fire extinguishers?
10kg
What weight are APU fire extinguishers?
5kg
Overpressure relief function - RED?
1700psi +
Overpressure relief function - YELLOW?
Bottle is discharged
What is the firing circuit supplied by to make it as safe as possible?
Hot battery bus
