COMPOSITE MATERIAL FIRE FIGHTING RESEARCH

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COMPOSITE MATERIAL FIRE FIGHTING RESEARCH

• ARFF Working Group
• October 8, 2010
• Phoenix, AZ
• Presented by
• Keith Bagot
• Airport Safety Specialist
• Airport Safety Technology RD Section
• John Hode
• ARFF Research Specialist
• SRA International, Inc.

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Presentation Outline

• FAA Research Program Overview
• Composite Aircraft Skin Penetration Testing
• Composite Material Cutting Apparatus
• Development of Composite Material Live Fire Test
  Protocol

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FAA Research Program Overview
FAA HQ, Washington, DC
Tyndall AFB, Panama City, FL
FAA Technical Center, Atlantic City, NJ
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FAA Research Program Overview
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FAA Research Program Overview

• Program Breakdown
• ARFF Technologies
• Operation of New Large Aircraft (NLA)
• Advanced Composite Material Fire Fighting

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FAA Research Program Overview

• Past Projects
• High Reach Extendable Turrets
• Aircraft Skin Penetrating Devices
• High Flow Multi-Position Bumper Turrets
• ARFF Vehicle Suspension Enhancements
• Drivers Enhanced Vision Systems
• Small Airport Fire Fighting Systems
• Halon Replacement Agent Evaluations

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Advanced Composite Material Fire Fighting

• Expanded Use of Composites
• Increased use of composites in commercial
  aviation has been well established
• 12 in the B-777 (Maiden flight 1994)
• 25 in the A380 (Maiden flight 2005)
• 50 in both B-787 A350 (Scheduled)
• A380, B-787 A350 are the first to use
  composites in pressurized fuselage skin

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Advanced Composite Material Fire Fighting

• Research Areas
• Identify effective extinguishing agents.
• Identify effective extinguishing methods.
• Determine quantities of agent required.
• Identify hazards associated airborne composite
  fibers.

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Composite Aircraft Skin Penetration Testing
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Composite Aircraft Skin Penetration Testing

• 3 Types of Piercing Technologies

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Composite Aircraft Skin Penetration Testing

• Objectives
• Provide guidance to ARFF departments to deal with
  the advanced materials used on next generation
  aircraft.
• Determine the force needed to penetrate fuselage
  sections comprised of composites and compare to
  that of aluminum skins.
• If required forces are greater, will that
  additional force have a detrimental effect on
  ARFF equipment.
• Determine range of offset angles that will be
  possible when penetrating composites and compare
  to that of aluminum skins.

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Composite Aircraft Skin Penetration Testing

• Phase 1 Small-Scale Laboratory Characterization
  of Material Penetration for Aluminum, GLARE and
  CRFP (Drexel University)
• Phase 2 Full-Scale Test using the Penetration
  Aircraft Skin Trainer (PAST) Device (FAA-TC)
• Phase 3 Full-Scale Test Using NLA Mock-Up Fire
  Test Facility (Tyndall Air Force Base)

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Composite Aircraft Skin Penetration Testing

• Test Matrix Developed
• Three Materials
• Aluminum (Baseline)
• GLARE
• CFRP
• Three Thickness
• Three Loading Rates
• Two Angles of Penetration
• Three Repetitions

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Composite Aircraft Skin Penetration Testing
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Composite Aircraft Skin Penetration Testing
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Composite Aircraft Skin Penetration Testing
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ASPN Penetration/Retraction Process
Material deformation tip region penetration
Conical region penetration
Cylindrical region penetration
Retraction
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ASPN Penetration and Retraction Forces
NP
PP
PR
NR
Constant force is required to perforate aluminum
panels after initial penetration Increasing force
is required to perforate CFRP and GLARE panels
after initial penetration
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Maximum Plate Penetration (PP) and Plate
Retraction (PR ) Loads at 0.001 and 0.1 in/s

• For Aluminum panels Retraction load is higher
  than penetration load, caused by petals gripping
  the panel upon retraction (due to elastic
  recovery)
• For GLARE and CFRP panels Penetration load is
  higher than retraction load - petals remain
  deformed (due to local damage of composite plies)

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Maximum Nozzle Penetration (NP) and Nozzle
Retraction (NR ) Loads at 0.001 and 0.1 in/s

• For Aluminum panels Retraction load is higher
  than penetration load, caused by petals gripping
  the panel upon retraction (due to elastic
  recovery)
• For GLARE and CFRP panels Penetration load is
  higher than retraction load - petals remain
  deformed (due to local damage of composite plies)

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Petals Formation
GLARE (Normal Penetration)
Aluminum (Normal Penetration)
CRF (Normal Penetration)
Aluminum (Oblique Penetration)
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Composite Material Cutting Apparatus
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Composite Material Cutting Apparatus

• Purpose
• Increased use of composite materials on aircraft
• Limited data available on cutting performance of
  current fire fighting tools on composite
  materials
• Aim to establish a reproducible and scientific
  test method for assessing the effectiveness of
  fire service rescue saws and blades on aircraft
  skin materials

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Composite Material Cutting Apparatus

• Objectives
• Create an objective test method by eliminating
  the human aspect of testing
• Design a test apparatus that facilitates testing
  of 4X2 panels of aluminum, GLARE, and CFRP
• Measure
• Blade Wear
• Blade Temperature
• Blade Speed
• Plunge Force
• Axial Cut Force
• Cut Speed
• Utilize computer software and data acquisition
  devices to monitor and log data in real time

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Composite Material Cutting Apparatus
Design Progression
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Composite Material Cutting Apparatus
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Composite Material Cutting Apparatus
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Composite Material Cutting Apparatus
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Composite Material Cutting Apparatus
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Development of a Composite Material Fire Test
Protocol
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Development of a Composite Material Fire Test
Protocol
What we knew before this testing
ALUMINUM CARBON/EPOXY GLARE
Norm for ARFF Unfamiliar to ARFF Unfamiliar to ARFF
Melts at 660C (1220F) Resin ignites at 400C (752F) Outer AL melts, glass layers char
Burn-through in 60 seconds Resists burn-through more than 5 minutes Resists burn-through over 5 minutes
Readily dissipates heat Holds heat May hold heat
Current Aircraft B787 A350 2 Sections of A380 skin
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FedEx DC10-10F, Memphis, TN 18 December
2003 Aluminum skinned cargo flight
Traditionally, the focus is on extinguishing the
external fuel fire, not the fuselage.
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Representative IncidentAir China at Japan Naha
Airport, August 19, 2007
4 minutes total video 3 minutes tail
collapses ARFF arrives just after tail collapse
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Development of a Composite Material Fire Test
Protocol

• External Fire Control Defined
• Extinguishment of the body of external fire
• Our question Will the composite skin continue to
  burn after the pool fire is extinguished, thereby
  requiring the fire service to need more
  extinguishing agent in the initial attack?
• Cooling of the composite skin to below 300F
• Our question How fast does the composite skin
  cool on its own and how much water and foam is
  needed to cool it faster?
• 300F is recommended in the IFSTA ARFF textbook
  and by Air Force T.O. 00-105E-9. (Same report
  used in both)
• Aircraft fuels all have auto ignition
  temperatures above 410F. This allows for some
  level of a safety factor.

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Creation of a Test Method

• First objective
• Determine if self-sustained combustion or
  smoldering will occur.
• Determine the time to naturally cool below 300F
  (150C)

• Second objective
• Determine how much fire agent is needed to
  extinguish visible fire and cool the material
  sufficiently to prevent re-ignition.

• Exposure times of Initial tests
• 10, 5, 3, 2, 1 minutes
• FAR Part 139 requires first due ARFF to arrive in
  3 minutes.
• Actual response times can be longer or shorter.

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Initial Test Set-up
Color Video
FLIR
Color Video at 45 Front view
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Initial Test Set-up
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Test 10 Video
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Initial Results

• Longer exposure times inflicted heavy damage on
  the panels.
• Longer exposures burned out much of the resin.
• Backside has hard crunchy feel.
• Edges however, seem to have most of the resin
  intact. Edge area matched 1 inch overlap of
  Kaowool.

Test 6, 10 minute exposure
Edge View
Front (fire side)
Back (non-fire side)
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Panel Temperatures
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Other Test Configurations

• Tests 22 and 23
• The panel was cut into 4 pieces and stacked with
  ¾ inch (76.2mm) spaces between.
• Thermocouples placed on top surface of each
  layer.
• Exposure time 1 minute.

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Other Test Configurations cont.

• This configuration not representative of an
  intact fuselage as in the China Air fire.
• Measured temperatures in the vicinity of 1750F
  (962C).
• Wind (in Test 22) caused smoldering to last 52
  seconds longer.

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Initial Findings

1. Post-exposure flaming reduces quickly without
   heat source
2. Off-gassing causes pressurization inside the
   panel causing swelling
3. Internal off-gassing can suddenly and rapidly
   escape
4. Off-gas/smoke is flammable
5. Longer exposures burn away more resin binder

1. Smoldering can occur
2. Smoldering areas are hot enough to cause
   re-ignition
3. Smoldering temperatures can be near that of fuel
   fires
4. Presence of smoke requires additional cooling
5. Insulated areas cooled much more slowly than
   uninsulated areas

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Further Development of Fire Test Protocol

• Data from first series of tests was used to
  further modify the protocol development.
• For example, larger panels and different heat
  sources were utilized in this round of
  development.
• Larger test panels will be needed for the agent
  application portion of the protocol.
• Lab scale testing conducted to identify burn
  characteristics.
• Testing was conducted by Hughes Associates Inc.
  (HAI).

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Further Development of Fire Test Protocol

• Lab scale tests
• ASTM E1354 Cone Calorimeter
• Data to support exterior fuselage flame
  propagation/spread modeling
• ASTM E1321 Lateral Flame Spread Testing (Lateral
  flame spread)
• Thermal Decomposition Apparatus (TDA)
• Thermal Gravimetric Analysis (TGA)
• Differential Scanning Calorimetry (DSC)
• Pyrolysis Gas Chromatograph/Mass Spectroscopy
  (PY-GC/MS)

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Further Development of Fire Test Protocol

• Secondary test configuration (agent application
  to be tested at this scale)
• Three different heat sources evaluated
• Propane fired area burner (2 sizes)
• Propane torch
• Radiant heater
• Sample panels are 4 feet wide by 6 feet tall
• Protection added to test rig to avoid edge
  effects.
• A representative backside insulation was used in
  several tests.

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Further Development of Fire Test Protocol

• 12 total tests conducted
• 9 with OSB
• 1 uninsulated
• 8 insulated
• 3 with CFRP
• 1 uninsulated
• 2 insulated

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OSB Exposed to Large Area Burnerwith Insulation
Backing
Large Area Burner On
Burner Off 30 seconds
Burner Off 0 seconds
Burner Off 100 seconds
Burner Off 60 seconds
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CFRP Exposed to Torch Burner with Insulation
Backing
Torch Ignition
1 minute after ignition
1.5 minutes after ignition
15 seconds after torches out
4 minutes after ignition Torches Out
2.5 minutes after ignition
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Findings

• Ignition occurred quickly into exposure
• Vertical/Lateral flame spread only occurred
  during exposure
• Post-exposure flaming reduced quickly without
  heat source
• Jets of internal off-gassing escaped near heat
  source from the backside
• Generally, results are consistent with small
  scale data

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Test Conclusions

• OSB vs. CFRP
• Both materials burn and spread flame when exposed
  to large fire
• Heat release rates and ignition times similar
• The thicker OSB contributed to longer burning

• Large Scale Implications
• OSB can be used as a surrogate for CFRP in
  preliminary large scale tests
• Flaming and combustion does not appear to
  continue after exposure is removed
• Since there was no or very little post exposure
  combustion, no suppression tests performed as
  planned
• Minimal agent for suppression of intact aircraft?

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Qualifiers to Results

• Need to check GLARE
• No significant surface burning differences
  anticipated ( may be better than CFRP)
• Verify /check CFRP for thicker areas (longer
  potential burning duration)
• Evaluate edges/separations
• Wing control surfaces
• Engine nacelle
• Stiffeners
• Post crash debris scenario
• Can a well established fire develop in a
  post-crash environment?

EXAMPLE COMPLEX GEOMETRY FIRE TEST SETUP FOR CFRP
FLAMMABILITY EVALUATION.
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Summary

• Carbon fiber composite has not shown flame spread
  and quickly self-extinguish in the absence of an
  exposing fire.
• Carbon fiber can achieve very high temperatures
  depending on configuration through radiation.
• Initial lab tests and fire tests show similar
  results and are consistent.
• Smoke should be used as an indicator of hot spots
  that must be further cooled.
• OSB can be used for large scale testing to
  establish parameters to save very expensive
  carbon fiber for data collection.

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Questions or Comments?

• FAA Technical Center
• Airport Technology RD Team
• AJP-6311, Building 296
• Atlantic City International Airport, NJ 08405
• Keith.Bagot_at_faa.gov 609-485-6383
• John_Hode_at_sra.com 609-601-6800 x207
• www.airporttech.tc.faa.gov
• www.faa.gov/airports/airport_safety/aircraft_rescu
  e_fire_fighting/index.cfm