INTERNATIONAL AIRCRAFT SYSTEMS FIRE PROTECTION WORKING GROUP MEETING

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INTERNATIONAL AIRCRAFT SYSTEMS FIRE PROTECTION
WORKING GROUP MEETING
AN INTEGRATED FIRE PROTECTION SYSTEM
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AN INTEGRATED FIRE PROTECTION SYSTEM

• BACKGROUND
• The concept of an Integrated Fire Protection
  System has been proposed by the FAA
• Transport Canada have commissioned a research
  study to
• Identify the feasibility, practicality, and
  issues that are likely to result from the
  implementation of such a system prior to the
  concept being considered a cost-beneficial safety
  enhancement.

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AN INTEGRATED FIRE PROTECTION SYSTEM
WATER SYSTEM
OBIGGS/ OBOGS
PAX/CREW O2 SUPPLY
FUEL TANKS
CARGO BAYS
CABIN
WHEEL WELLS
E/E BAYS
COCKPIT/CABIN HIDDEN AREAS
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AN INTEGRATED FIRE PROTECTION SYSTEM

• Primary areas addressed by the Study to date

• Benefit Assessment
• Initial feasibility assessment of cargo
  compartment water mist/nitrogen system and
  preliminary weight assessment.
• Identification of Cargo Bay Inerting system
  issues.
• Initial feasibility assessment of a hidden areas
  on-demand inerting system.

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INTEGRATED FIRE PROTECTIONSYSTEM

• BENEFIT ASSESSMENT

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BENEFIT ASSESSMENT

• The assessed benefit of an Integrated Fire
  Protection System is assessed to be in the region
  of
• 45 lives saved per year

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INTEGRATED FIRE PROTECTIONSYSTEM

• CARGO COMPARTMENT INERTING SYSTEM

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Cargo Compartment Inerting System

• Water Mist Systems alone have not as yet been
  shown to meet the MPS for Cargo Bays.
• However FAA testing has shown that a Water Mist
  system supplemented by Nitrogen can have the
  capability to meet the MPS

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Cargo Compartment Inerting System
CARGO BAY HALON REPLACEMENT
WATER MIST WITH NITROGEN ENRICHED AIR
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Cargo Compartment Inerting System

• Using the number of Air Separation Modules (ASMs)
  likely to be needed for Center Fuel Tank
  Inerting, Cargo Bay inerting times are likely to
  be unacceptably long (based on NEA Flow Rate of
  9.6 ft3/min and 5 Oxygen concentration). This is
  likely to result in excessive quantities of water
  being required to meet the MPS.
• Hence consideration has been given to the
  feasibility of using additional Air Separation
  Modules to provide greater flow rates of Nitrogen
  Enriched Air.

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Cargo Compartment Inerting System

• The number of Air Separation Modules needed to
  inert a Center Fuel Tank is almost directly
  related to Tank Volume

Can the industry confirm the required number of
ASMs for Fuel Tank Inerting for their airplanes?
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Cargo Compartment Inerting System
The Water Mist System used by FAA that met the
MPS on the TC10 Cargo Bay was based on inerting
the compartment to 10 within circa 15
minutes. The ASMs required, for a variety of
aircraft, to achieve this inerting level were
derived from a simplistic model developed during
this study. The volumes of water required to meet
the MPS were also derived from the FAA TC10
testing.
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Cargo Compartment Inerting System
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Cargo Compartment Inerting System
WATER MIST WITH NITROGEN ENRICHED AIR
CARGO BAY HALON REPLACEMENT
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Cargo Compartment Inerting System
Water Weight based on FAA TC10 test and scaling
was based on inerting to 10 within circa 15
minutes (although 12 inerting would probably
have been sufficient) Assessment of fluid weights
based on simplistic model developed as part of
this study
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Cargo Compartment Inerting System
Note These weights do not take into account
container weights which could be high for the
Nitrogen container. Data is required on the
relationship between current technology container
weights and gas pressure/mass.
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Cargo Compartment Inerting System
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Cargo Compartment Inerting System -Issues

• ISSUES
• Is 12 oxygen the correct inerting level?
• Flow Control in Cargo Bay to ensure that there is
  no flow to the cabin and no structural issues
  within the Cargo Bay
• Model development to take account of variation in
  leakage rates, pressure control and NEA/Nitrogen
  Flow Rates

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Cargo Compartment Inerting System -Issues

• ISSUES
• ASM performance needs to be understood better
• Can Water Mist system performance be improved? -
  optimized nozzles, number and pitch of nozzles,
  dual fluid nozzles, system controlled to minimise
  water weight, etc
• Optimisation of Water/Pure Nitrogen (or other
  extinguishing agent) concentrations

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Cargo Compartment Inerting System -Issues

• ISSUES
• Depletion of oxygen due to the fire and
  absorption by the water needs to be better
  understood
• Water Additives for improved fire suppression,
  anti-freeze, etc taking into consideration the
  potential side effects especially when used for
  the Cabin Water Mist system.

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INTEGRATED FIRE PROTECTIONSYSTEM

• HIDDEN AREA FIRE SUPPRESSION

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HIDDEN AREA FIRE SUPPRESSION

• Feasibility of OBIGGS generated NEA to inert
  hidden areas in the overhead area

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HIDDEN AREA FIRE SUPPRESSION

• The time for a hidden fire to become
  non-survivable

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HIDDEN AREA FIRE SUPPRESSION

• Based on the aircraft studied to date it would
  appear that a significant proportion of the
  hidden areas could be inerted within 8 minutes to
  oxygen concentrations of 12 using only the Air
  Separation Modules needed for Center Fuel Tank
  Inerting.

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HIDDEN AREA FIRE SUPPRESSION

• Only the volume of the hidden area in close
  proximity to the fire requires inerting
• Use the number of ASMs currently fitted to
  aircraft for CWT inerting to inert portions of
  the hidden areas to 12 O2 within 8 minutes

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HIDDEN AREA FIRE SUPPRESSION
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HIDDEN AREA FIRE SUPPRESSION

• It is theoretically feasible to use the ASMs
  currently installed on aircraft for CWT inerting
  for hidden area inerting