    Aviation Safety: Advancements Being Pursued to Improve Airliner
    Cabin Occupant Safety and Health (03-OCT-03, GAO-04-33).

    Airline travel is one of the safest modes of public
    transportation in the United States. Furthermore, there are
    survivors in the majority of airliner crashes, according to the
    National Transportation Safety Board (NTSB). Additionally, more
    passengers might have survived if they had been better protected
    from the impact of the crash, smoke, or fire or better able to
    evacuate the airliner. As requested, GAO addressed (1) the
    regulatory actions that the Federal Aviation Administration (FAA)
    has taken and the technological and operational improvements,
    called advancements, that are available or are being developed to
    address common safety and health issues in large commercial
    airliner cabins and (2) the barriers, if any, that the United
    States faces in implementing such advancements.
    -------------------------Indexing Terms-------------------------
    REPORTNUM:   GAO-04-33
        ACCNO:   A08662
      TITLE:     Aviation Safety: Advancements Being Pursued to Improve
    Airliner Cabin Occupant Safety and Health
         DATE:   10/03/2003
      SUBJECT:   Aircraft accidents
    	     Aircraft maintenance
    	     Airline regulation
    	     Safety regulation
    	     Transportation safety
    	     Commercial aviation
    	     Research and development

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    GAO-04-33

    United States General Accounting Office

    GAO	Report to the Ranking Democratic Member, Committee on Transportation

                      and Infrastructure, House of Representatives

    October 2003

    AVIATION SAFETY

    Advancements Being Pursued to Improve Airliner Cabin Occupant Safety and Health

                                           a

    GAO-04-33

    Highlights of GAO-04-33, a report to the Ranking Democratic Member,
    Committee on Transportation and Infrastructure, House of Representatives

    Airline travel is one of the safest modes of public transportation in the
    United States. Furthermore, there are survivors in the majority of
    airliner crashes, according to the National Transportation Safety Board
    (NTSB). Additionally, more passengers might have survived if they had been
    better protected from the impact of the crash, smoke, or fire or better
    able to evacuate the airliner. As requested, GAO addressed (1) the
    regulatory actions that the Federal Aviation Administration (FAA) has
    taken and the technological and operational improvements, called
    advancements, that are available or are being developed to address common
    safety and health issues in large commercial airliner cabins and (2) the
    barriers, if any, that the United States faces in implementing such
    advancements.

    This report contains recommendations to FAA to initiate discussions with
    NTSB to facilitate the exchange of medical information from accident
    investigations and to improve the cost and effectiveness data available
    for setting priorities for research on cabin occupant safety and health.
    FAA generally agreed with the report's contents and its recommendations.

    www.gao.gov/cgi-bin/getrpt?GAO-04-33.

    To view the full product, including the scope and methodology, click on
    the link above. For more information, contact Gerald Dillingham at (202)
    512-2834 or dillinghamg@gao.gov.

    October 2003

    AVIATION SAFETY

    Advancements Being Pursued to Improve Airliner Cabin Occupant Safety and Health

    FAA has taken a number of regulatory actions over the past several decades
    to address safety and health issues faced by passengers and flight
    attendants in large commercial airliner cabins. GAO identified 18
    completed actions, including those that require safer seats, cushions with
    better fire-blocking properties, better floor emergency lighting, and
    emergency medical kits. GAO also identified 28 advancements that show
    potential to further improve cabin safety and health. These advancements
    vary in their readiness for deployment. Fourteen are mature, currently
    available, and used in some airliners. Among these are inflatable lap seat
    belts, exit doors over the wings that swing out on hinges instead of
    requiring manual removal, and photo-luminescent floor lighting. The other
    14 advancements are in various stages of research, engineering, and
    development in the United States, Canada, or Europe.

    Several factors have slowed the implementation of airliner cabin safety
    and health advancements. For example, when advancements are ready for
    commercial use, factors that may hinder their implementation include the
    time it takes for (1) FAA to complete the rule-making process, (2) U.S.
    and foreign aviation authorities to resolve differences between their
    respective requirements, and (3) the airlines to adopt or install
    advancements after FAA has approved their use. When advancements are not
    ready for commercial use because they require further research, FAA's
    processes for setting research priorities and selecting research projects
    may not ensure that the limited federal funding for cabin safety and
    health research is allocated to the most critical and cost-effective
    projects. In particular, FAA does not obtain autopsy and survivor
    information from NTSB after it investigates a crash. This information
    could help FAA identify and target research to the primary causes of death
    and injury. In addition, FAA does not typically perform detailed analyses
    of the costs and effectiveness of potential cabin occupant safety and
    health advancements, which could help it identify and target research to
    the most cost-effective projects.

    A Survivable Large Commercial Airliner Accident

    Contents

      Letter

    Results in Brief
    Background
    Regulatory Actions Have Been Taken and Additional Advancements

    Are Under Way to Improve Cabin Occupants' Safety and Health Several
    Factors Have Slowed the Implementation of Cabin

    Occupant Safety and Health Advancements Conclusions Recommendations for
    Executive Action Agency Comments and Our Evaluation

    1 3 7

    9

    19 28 29 30

    Appendixes

    Appendix I: Appendix II:

    Appendix III: Appendix IV:

    Appendix V:

    Appendix VI:

    Objectives, Scope, and Methodology 31

    Canada and Europe Cabin Occupant Safety and Health
    Responsibilities 35
    Canada 35
    Europe 36

    Summary of Key Actions FAA Has Taken to Improve Airliner
    Cabin Safety and Health Since 1984 40

    Summaries of Potential Impact Safety Advancements 43 Retrofitting All
    Commercial Aircraft with More Advanced Seats 43 Improving the Ability of
    Airplane Floors to Hold Seats in an

    Accident 48 Preventing Overhead Storage Bin Detachment to Protect
    Passengers

    in an Accident 50 Child Safety Seats 52 Inflatable Lap Belt Air Bags 56

    Summaries of Potential Fire Safety Advancements 58 Fuel Tank Inerting 58
    Arc Fault Circuit Breaker 62 Multisensor Detectors 64 Water Mist Fire
    Suppression 67 Fire-Safe Fuels 71 Thermal Acoustic Insulation Materials 73
    Ultra-Fire-Resistant Polymers 76 Airport Rescue and Fire-Fighting
    Operations 79

    Summaries of Potential Improved Evacuation Safety Advancements 82

                                        Contents

    Passenger Safety Briefings 82 Exit Seat Briefing 84 Photo-luminescent
    Floor Track Marking 85 Crewmember Safety and Evacuation Training 88
    Acoustic Attraction Signals 90 Smoke Hoods 92 Exit Slide Testing 97
    Overwing Exit Doors 100 Next Generation Evacuation Equipment and
    Procedures 102 Personal Flotation Devices 104

    Appendix VII:	Summaries of General Cabin Occupant Safety and Health
    Advancements 106 Advanced Warnings of Turbulence 106 Preparations for
    In-flight Medical Emergencies 107 Reducing Health Risks to Passengers with
    Certain Medical

    Conditions 108 Improved Awareness of Radiation Exposure 110 Occupational
    Safety and Health Standards for Flight

    Attendants 112

    Appendix VIII:	Application of a Cost Analysis Methodology to Inflatable
    Lap Belts 115 Inflatable Lap Belts 115 Summary of Results 115 Methodology
    116

    Appendix IX:	GAO Contacts and Staff Acknowledgments 118 GAO Contacts 118
    Staff Acknowledgments 118

    Tables	Table 1: Table 2: Table 3:

    Table 4:

    Table 5:

    Regulatory Actions Taken by FAA to Improve Cabin
    Occupant Safety and Health Since 1984 4
    Advancements with Potential to Improve Cabin Occupant
    Safety and Health 4
    Status of 10 Significant FAA Rules Pertaining to Airliner
    Cabin Occupants' Safety and Health, Fiscal Year 1995
    through September of Fiscal Year 2003 20
    Costs to Equip an Average-sized Airplane in the U.S. Fleet
    with Inflatable Lap Seat Belts, Estimated under Alternative
    Scenarios (In 2002 discounted dollars) 116
    Key Assumptions 117

                                        Contents

    Figures	Figure 1: Figure 2: Figure 3:

    Figure 4:

    Figure 5: Figure 6: Figure 7: Figure 8: Figure 9:

    Inflatable Lap Belt Air Bag Inflation Sequence
    Manual "Self Help" and "Swing Out" Over-Wing Exits
    Funding for Federal Research on Cabin Occupant Safety
    and Health Issues, by Facility, Fiscal Years 2000-2005
    Allocation of Federal Funding for Aircraft Cabin
    Occupant Safety and Health Research, Fiscal Year
    2003
    Coach Seating and Impact Position in Coach Seating
    Examples of Child Safety Seats
    Water Mist Nozzle and Possible Placement
    Fire Insulation Blankets
    Flammable Cabin Materials and Small-scale Material Test
    Device

                                         11 15

    25

    26 45 53 68 74

    77 80

    83

    87 90 94

    98 102 Figure 10: Airport Rescue and Fire Training

    Figure 11: Airline Briefing to Passengers on Safety Briefing Cards

    Figure 12: Floor Track Marking Using Photo-luminescent Materials

    Figure 13: Test Installation of Acoustic Signalling Device

    Figure 14: An Example of a Commercially Available Smoke Hood

    Figure 15: Drawing of Possible Emergency Slide Testing of FAA's 747 Test
    Aircraft

    Figure 16: Airbus' Planned Double Deck Aircraft

    Contents

    Abbreviations

    ACRM Advanced Crew Resource Management
    CAMI Civil Aerospace Medical Institute
    CRM Crew Resource Management
    DGAC Direction Generale de l'Aviation Civile
    DOT Department of Transportation
    DOT IG Department of Transportation's Inspector General
    DVT deep vein thrombosis
    EASA European Aviation Safety Agency
    FAA Federal Aviation Administration
    ICAO International Civil Aviation Organization
    JAA European Joint Aviation Authorities
    NASA National Aeronautics and Space Administration
    NIOSH National Institute of Safety and Health
    NTSB National Transportation Safety Board
    OSHA Occupational Health and Safety Administration
    TRL Technical Readiness Level
    TSO Technical Standing Order

    This is a work of the U.S. government and is not subject to copyright
    protection in the United States. It may be reproduced and distributed in
    its entirety without further permission from GAO. However, because this
    work may contain copyrighted images or other material, permission from the
    copyright holder may be necessary if you wish to reproduce this material
    separately.

    A

    United States General Accounting Office Washington, D.C. 20548

    October 3, 2003

    The Honorable James L. Oberstar

    Ranking Democratic Member

    Committee on Transportation and Infrastructure House of Representatives

    Dear Mr. Oberstar:

    Airline travel is one of the safest modes of public transportation in the
    United States, in large part because of the Congress's, Federal Aviation
    Administration's (FAA), commercial airlines', aircraft manufacturers', and
    airports' combined efforts to prevent commercial airliner accidents.
    Furthermore, although a few airliner accidents are catastrophic, there are
    survivors in a majority of crashes. According to the National
    Transportation Safety Board (NTSB), passengers survived in 19 of the 26
    U.S. large commercial airliner accidents that occurred from 1982 through
    2001, and in these 19 accidents, over 76 percent of the passengers (1,523
    of 1,988) survived.1 Additionally, some of the passengers who died in
    these accidents might have survived if they had been better protected from
    the impact of the crash or from the effects of smoke and fire and had been
    better able to evacuate the airliner. This possibility of survival has led
    federal safety officials to focus their efforts not only on preventing
    airliner accidents, but also on increasing the chances of surviving them.

    Over the past several decades, FAA has been taking regulatory actions to
    require the implementation of technological and operational improvements
    in cabin occupant safety and health to help increase passengers' chances
    of surviving large commercial airliner accidents. In addition, FAA and the
    aviation community have been conducting research on new technological and
    operational improvements, which we refer to in this report as
    advancements, whose implementation could further increase passengers'
    chances of survival and improve the safety and health of passengers and
    flight attendants. This report discusses regulatory actions that FAA has
    taken as well as potential advancements in cabin occupant safety and
    health that are (1) currently available but not yet implemented or
    installed, and (2) not yet available and subject to additional research to
    advance the

    1Large, or `transport category' commercial aircraft are defined as those
    with a capacity of 30 or more passengers or a load of 7,500 pounds or
    more.

    technology or lower costs. For implementation of these advancements to
    occur, FAA often has to take regulatory action, that is, issuing
    regulations or airworthiness directives that require the implementation of
    technological and operational improvements in cabin occupant safety and
    health. FAA continues to pursue regulatory initiatives as well as conduct
    research to improve cabin occupant safety and health. The aviation
    community is also attempting to enhance the safety and health of those
    traveling and working in airliner cabins through such measures as
    providing earlier warnings of turbulence and information on the potential
    to develop blood clots on long-distance flights. Besides increasing cabin
    occupants' safety and health, these actions and efforts could benefit the
    airlines by helping to restore passengers' confidence in the safety of
    flight and thereby increasing the demand for air travel, which fell
    sharply after September 11, 2001, and still remains below fiscal year 2000
    levels.

    In response to your request, this report addresses the following
    questions: (1) What regulatory actions has FAA taken, and what key
    advancements are available or being developed by FAA and others to address
    safety and health issues faced by passengers and flight attendants in
    large commercial airliner cabins? (2) What factors, if any, slow the
    implementation of advancements in cabin occupant safety and health? In
    addition, as requested, we identified some factors faced by Canada and
    Europe in their efforts to improve cabin occupant safety and health (see
    app. II).

    To identify the regulatory actions FAA has taken and the key advancements
    that are available or being developed to address safety and health issues
    facing passengers and flight attendants (cabin occupants), we reviewed the
    relevant literature, interviewed FAA officials, and reviewed FAA's
    documentation on the regulatory actions it has taken to enhance cabin
    occupant safety and health. As part of this effort, FAA officials
    identified key regulatory actions that had been completed in this area. In
    addition, we interviewed other aviation safety experts in government,
    industry, and academia from the United States, Canada, and Europe. (See
    app. I for additional information.) Through our reviews and interviews, we
    found that FAA's regulatory actions and advancements fell into four broad
    categories-three related to safety in the event of a crash and one related
    to general cabin occupant safety and health. The regulatory actions and
    advancements related to safety in the event of a crash are those actions
    taken to (1) minimize injuries from the impact of a crash, (2) prevent
    fire or mitigate its effects, and (3) improve the chances and speed of
    evacuation. In addition, we discuss the regulatory actions and
    advancements FAA has taken to address a fourth category-improving the
    safety and health of

    cabin occupants. Using the results of our reviews and interviews, we
    identified and categorized 28 advancements that are currently available or
    being developed, including 5 impact advancements, 8 fire advancements, 10
    evacuation advancements, and 5 cabin occupant safety and health
    advancements. For each of these advancements, we discuss the background,
    research, and regulatory status.2 We also discuss each advancement's
    technological readiness for use in the existing commercial airliner fleet
    or in newly produced commercial airplanes. To identify factors that have
    slowed implementation of airliner cabin occupant safety and health
    advancements, we interviewed FAA, NTSB, and industry officials. In
    addition, we analyzed documentation from FAA, NTSB, and aviation safety
    experts to identify factors relating to key issues within FAA and the
    aviation community related to prioritizing and funding research, choosing
    advancements for regulatory implementation, and gaining the aviation
    community's acceptance of these advancements.

    This report does not address cabin air quality because we are doing work
    in this area for another congressional requester. In addition, given the
    large scope of this review, the report does not focus on safety and health
    issues for flight deck crews (pilots and flight engineers) since they face
    some unique issues not faced by cabin occupants. It also does not address
    aviation security issues, such as hijackings, sabotage, or terrorist
    activities.

    We conducted our review from January 2002 through September 2003 in
    accordance with generally accepted government auditing standards.

    Results in Brief	FAA has taken a number of key regulatory actions over the
    past several decades to improve the safety and health of passengers and
    flight attendants in large commercial airliner cabins. We identified 18
    such completed regulatory actions that FAA has taken since 1984. Table 1
    shows the number of such actions by category and provides an example for
    each category of action.

    2In identifying 28 advancements, we are not suggesting that these are the
    only advancements being pursued, rather that these advancements have been
    recognized by aviation safety experts we contacted as offering promise for
    improving the safety and health of cabin occupants.

    Table 1: Regulatory Actions Taken by FAA to Improve Cabin Occupant Safety
    and Health Since 1984

    Number of key Category of regulatory action Example actions taken

    Minimize injuries from the impact Stronger seats of a crash

    Prevent fire or mitigate its effects Fire-blocking seat cushions

    Improve the chances and speed Emergency floor lighting of evacuation

    Improve the safety and health of Onboard emergency medical cabin occupants
    kits

    Source: GAO.

    We also identified 28 advancements that have the potential to increase the
    chances of surviving a commercial airliner crash and to improve the safety
    and health of cabin occupants-both passengers and flight attendants. Table
    2 shows the number of such advancements by category and provides an
    example for each.

    Table 2: Advancements with Potential to Improve Cabin Occupant Safety and Health

    Number of key Category of advancement Example advancements

    Minimize injuries from the impact of Lap seat belts with inflatable air a
    crash bags

    Prevent fire or mitigate its effects Reduced fuel tank flammability

    Improve the chances and speed of Improved passenger safety evacuation
    briefings

    Improve the safety and health of Advanced warnings of cabin occupants
    turbulence

    Source: GAO.

    These 28 advancements vary in their readiness for deployment. For example,
    14 of the technologies are currently available but not yet implemented or
    installed. Two of these, preparation for in-flight medical emergencies and
    improved insulation, were addressed through separate regulations. These
    regulations require airlines to install additional emergency medical
    equipment (automatic external defibrillators and enhanced emergency
    medical kits) by 2004, replace flammable insulation (metalized Mylar(R))
    with improved insulation by 2005, and manufacture

    new large commercial airliners with improved (thermal acoustic) insulation
    beginning September 2, 2005. Another currently available advancement is in
    FAA's rule-making process-retrofitting the entire existing fleet with
    significantly stronger seats. These seats, commonly referred to as 16g
    seats, for example, can withstand the force of an impact 16 times a
    passenger's body weight (16g), rather than 9 times (9g), as currently
    required primarily for new generation commercial aircraft.3 For the
    remaining 11 currently available advancements, while FAA does not require
    their use, some are being used by selected airlines. For example, some
    airlines have elected to use inflatable lap seat belts, exit doors over
    the wings that swing out on hinges instead of requiring manual removal,
    and photo-luminescent floor lighting.4 In addition, some of these
    advancements are available for purchase by the flying public, including
    smoke hoods and child safety seats certified for use on commercial
    airliners. The remaining 14 advancements are in various stages of
    research, engineering, and development in the United States, Canada, or
    Europe.

    Several factors slow the implementation of advancements in cabin occupant
    safety and health, including those that are currently available, but have
    not yet been implemented or installed and those that require further
    research to demonstrate their effectiveness or lower their costs before
    they are ready for implementation. For those that are ready, and for which
    design and certification standards have been developed, FAA may undertake
    the rule-making process to require their implementation. As our prior work
    has shown, this process can take years. In addition, FAA and its
    international counterparts attempt to reach agreement on, or harmonize,
    their requirements for aviation procedures and equipment. The authorities'
    current harmonization process has resulted in a backlog, which has slowed
    the implementation of several cabin occupant safety and health
    advancements. Finally, the airlines must implement the advancements. While
    some advancements, such as improved safety briefings, can be implemented
    quickly and economically, others, such as retrofitting commercial aircraft
    with stronger passenger seats, require time-

    3A separate rule-making effort in 1988 required that newly manufactured
    aircraft be equipped with stronger, 16g seats; however, it did not require
    that the existing U.S. fleet of commercial aircraft be retrofitted with
    these seats.

    4FAA officials told us that using photo-luminescent lighting is a
    different way to meet an existing standard and, therefore, should not be
    considered an advancement in safety. However, because photo-luminescent
    floor lighting differs from standard floor lighting in that it works
    without electricity, some in the aviation community consider it a safety
    advancement.

    consuming, costly changes. FAA may give the airlines several years to
    retrofit their fleets in order to coordinate the change, when possible,
    with existing maintenance schedules and allow the airlines to absorb the
    associated costs. For advancements that require further research before
    they can be considered for use, FAA's multistep process for identifying
    potential cabin occupant safety and health research projects and
    allocating its limited resources to research projects on the advancements
    is hampered by a lack of autopsy and survivor information and cost and
    effectiveness data. According to FAA researchers, they have not had
    adequate access to autopsy reports and certain survivor information that
    NTSB obtains from autopsy reports and interviews with survivors during its
    investigations of commercial airliner accidents. This information could
    help FAA to identify the principal causes of death and injury and the
    major factors affecting survival, and to target research to advancements
    addressing these critical causes and factors. NTSB told us that while they
    provide large amounts of information on the causes of death and injury in
    information they make publicly available, they would consider making this
    additional information available to FAA if steps were taken to safeguard
    the privacy of victims and survivors. FAA's multistep process for
    selecting research projects on advancements includes consideration of such
    factors as their potential impact on accident prevention and accident
    mitigation; however, it does not include developing comparable estimates
    of cost and effectiveness for competing advancements to allow direct
    comparisons between them on their potential to reduce injuries and deaths.
    We developed a cost analysis methodology to illustrate how FAA could
    develop comparable cost estimates, to enhance its current process. The
    results of such analyses could be combined with similar estimates of
    effectiveness using data available from a variety of sources, including
    industry and academia. Using comparable cost and effectiveness data across
    the range of advancements could position the agency to choose more
    effectively between competing advancements, taking into account estimates
    of the number of injuries and fatalities that each advancement might
    prevent for the dollars invested. Such cost and effectiveness data would
    provide a valuable supplement to FAA's current process for setting
    research priorities and selecting projects for funding.

    This report contains a recommendation to the Secretary of Transportation
    to direct the FAA Administrator to initiate discussions with NTSB to
    facilitate the exchange of medical information from accident
    investigations. In addition, the report contains a recommendation to the
    FAA Administrator to improve the analyses available to decision makers
    responsible for setting research priorities and selecting projects for

    improving the safety and health of cabin occupants by (1) developing
    comparable cost estimates of potential advancements competing for funding
    and (2) developing or collecting data on the effectiveness of each
    potential advancement to reduce injuries or fatalities. In commenting on a
    draft of this report, FAA said that they generally agreed with the
    report's contents and its recommendations.

    Background	The safe travel of U.S. airline passengers is a joint
    responsibility of FAA and the airlines in accordance with the Federal
    Aviation Act of 1958, as amended, and the Department of Transportation
    Act, as amended. To carry out its responsibilities under these acts, FAA
    supports research and development; certifies that new technologies and
    procedures are safe; undertakes rule-makings, which when finalized form
    the basis of federal aviation regulations; issues other guidance, such as
    Advisory Circulars; and oversees the industry's compliance with standards
    that aircraft manufacturers and airlines must meet to build and operate
    commercial aircraft. Aircraft manufacturers are responsible for designing
    aircraft that meet FAA's safety standards, and air carriers are
    responsible for operating and maintaining their aircraft in accordance
    with the standards for safety and maintenance established in FAA's
    regulations. FAA, in turn, certifies aircraft designs and monitors the
    industry's compliance with the regulations.

    FAA's general process for issuing a regulation, or rule, includes several
    steps. When the regulation would require the implementation of a
    technology or operation, FAA first certifies that the technology or
    operation is safe. Then, FAA publishes a notice of proposed rule-making in
    the Federal Register, which sets forth the terms of the rule and
    establishes a period for the public to comment on it. Next, FAA reviews
    the comments by incorporating changes into the rule that it believes are
    warranted, and, in some instances, it repeats these steps one or more
    times. Finally, FAA publishes a final rule in the Federal Register. The
    final rule includes the date when it will go into effect and a time line
    for compliance.

    Within FAA, the Aircraft Certification Service is responsible for
    certifying that technologies are safe, including improvements to cabin
    occupant safety and health, generally through the issuance of new
    regulations, a finding certifying an equivalent level of safety, or a
    special condition when no rule covers the new technology. The
    Certification Service is also responsible for taking enforcement action to
    ensure the continued safety of aircraft by prescribing standards for
    aircraft manufacturers governing the

    design, production, and airworthiness of aeronautical products, such as
    cabin interiors. The Flight Standards Service is primarily responsible for
    certifying an airline's operations (assessing the airline's ability to
    carry out its operations and maintain the airworthiness of the aircraft)
    and for monitoring the operations and maintenance of the airline's fleet.

    FAA conducts research on cabin occupant safety and health issues in two
    research facilities, the Mike Monroney Aeronautical Center/Civil Aerospace
    Medical Institute in Oklahoma City, Oklahoma, and the William J. Hughes
    Technical Center in Atlantic City, New Jersey. The institute focuses on
    the impact of flight operations on human health, while the technical
    center focuses on improvements in aircraft design, operation, and
    maintenance and inspection to prevent accidents and improve survivability.
    For the institute or the technical center to conduct research on a
    project, an internal FAA requester must sponsor the project. For example,
    FAA's Office of Regulation and Certification sponsors much of the two
    facilities' work in support of FAA's rule-making activities. FAA also
    cooperates on cabin safety research with the National Aeronautics and
    Space Administration (NASA), academic institutions, and private research
    organizations.

    Until recently, NASA conducted research on airplane crashworthiness at its
    Langley Research Center in Hampton, Virginia. However, because of internal
    budget reallocations and a decision to devote more of its funds to
    aviation security, NASA terminated the Langley Center's research on the
    crashworthiness of commercial aircraft in 2002. NASA continues to conduct
    fire-related research on cabin safety issues at its Glenn Research Center
    in Cleveland, Ohio.

    NTSB has the authority to investigate civil aviation accidents and
    collects data on the causes of injuries and death for the victims of
    commercial airliner accidents. According to NTSB, the majority of
    fatalities in commercial airliner accidents are attributable to crash
    impact forces and the effects of fire and smoke. Specifically, 306 (66
    percent) of the 465 fatalities in partially survivable U.S. aviation
    accidents from 1983 through 2000 died from impact forces, 131 (28 percent)
    died from fire and smoke, and 28 (6 percent) died from other causes.5

    5NTSB, Survivability of Accidents Involving Part 121 U.S. Air Carrier
    Operations, 1983 Through 2000, NTSB/SR-01/01.

    Surviving an airplane crash depends on a number of factors. The space
    surrounding a passenger must remain large enough to prevent the passenger
    from being crushed. The force of impact must also be reduced to levels
    that the passenger can withstand, either by spreading the impact over a
    larger part of the body or by increasing the duration of the impact
    through an energy-absorbing seat or fuselage. The passenger must be
    restrained in a seat to avoid striking the interior of the airplane, and
    the seat must not become detached from the floor. Objects within the
    airplane, such as debris, overhead luggage bins, luggage, and galley
    equipment, must not strike the passenger. A fire in the cabin must be
    prevented, or, if one does start, it must burn slowly enough and produce
    low enough levels of toxic gases to allow the passenger to escape from the
    airplane. If there is a fire, the passenger must not have sustained
    injuries that prevent him or her from escaping quickly. Finally, if the
    passenger escapes serious injury from impact and fire, he or she must have
    access to exit doors and slides or other means of evacuation.

    Regulatory Actions Have Been Taken and Additional Advancements Are Under
    Way to Improve Cabin Occupants' Safety and Health

    Over the past several decades, FAA has taken a number of regulatory
    actions designed to improve the safety and health of airline passengers
    and flight attendants by (1) minimizing injuries from the impact of a
    crash, (2) preventing fire or mitigating its effects, (3) improving the
    chances and speed of evacuation, or (4) improving the safety and health of
    cabin occupants. (See app. III for more information on the regulatory
    actions FAA has taken to improve cabin occupant safety and health.)
    Specifically, we identified 18 completed regulatory actions that FAA has
    taken since 1984. In addition to these past actions, FAA and others in the
    aviation community are pursuing advancements in these four areas to
    improve cabin occupant safety and health in the future. We identified and
    reviewed 28 such advancements-5 to reduce the impact of a crash on
    occupants, 8 to prevent or mitigate fire and its effects, 10 to facilitate
    evacuation from aircraft, and 5 to address general cabin occupant safety
    and health issues.

    Minimizing Injuries from the The primary cause of injury and death for
    cabin occupants in an airliner

    Impact of a Crash 	accident is the impact of the crash itself. We
    identified two key regulatory actions that FAA has taken to better protect
    passengers from impact forces. For example, in 1988, FAA required stronger
    passenger seats for newly manufactured commercial airplanes to improve
    protection in

    survivable crashes.6 These new seats are capable, for example, of
    withstanding an impact force that is approximately 16 times a passenger's
    body weight (16g), rather than 9 times (9g), and must be tested
    dynamically (in multiple directions to simulate crash conditions), rather
    than statically (e.g., drop testing to assess the damage from the force of
    the weight alone without motion). In addition, in 1992, FAA issued a
    requirement for corrective action (airworthiness directive) for designs
    found not to meet the existing rules for overhead storage bins on certain
    Boeing aircraft, to improve their crashworthiness after bin failures were
    observed in the 1989 crash of an airliner in Kegworth, England, and a 1991
    crash near Stockholm, Sweden.

    We also identified five key advancements that are being pursued to provide
    cabin occupants with greater impact protection in the future. These
    advancements are either under development or currently available. Examples
    include the following:

    o 	Lap seat belts with inflatable air bags: Lap seat belts that contain
    inflatable air bags have been developed by private companies and are
    currently available to provide passengers with added protection during a
    crash. About 1,000 of these lap seat belts have been installed on
    commercial airplanes, primarily in the seats facing wall dividers
    (bulkheads) to prevent passengers from sustaining head injuries during a
    crash. (See fig. 1.)

    o 	Improved seating systems: Seat safety depends on several interrelated
    systems operating properly, and, therefore, an airline seat is most
    accurately discussed as a system. New seating system designs are being
    developed by manufacturers to incorporate new safety and aesthetic designs
    as well as meet FAA's 16g seat regulations to better protect passengers
    from impact forces. These seating systems would help to ensure that the
    seats themselves perform as expected (i.e., they stay attached to the
    floor tracks); the space between the seats remains adequate in a crash;
    and the equipment in the seating area, such as phones and video screens,
    does not increase the impact hazard.

    6FAA subsequently proposed, in October 2002, that the 16g seats be put
    into the entire existing fleet for both passengers and flight attendants
    within 14 years to better protect passengers from impact forces. We
    included this proposal in our list of advancements.

    o 	Child safety seats: Child safety seats could provide small children
    with additional protection in the event of an airliner crash. NTSB and
    others have recommended their use, and FAA has been involved in this issue
    for at least 15 years. While it has used its rule-making process to
    consider requiring their use, FAA decided not to require child safety
    restraints because its analysis found that if passengers were required to
    pay full fare for children under the age of 2, some parents would choose
    to travel by automobile and, statistically, the chances would increase
    that both the children and the adults would be killed. FAA is continuing
    to consider a child safety seat requirement.

    Figure 1: Inflatable Lap Belt Air Bag Inflation Sequence

    Appendix IV contains additional information on the impact advancements we
    have identified.

    Preventing Fire or Mitigating Its Effect

    Fire prevention and mitigation efforts have given passengers additional
    time to evacuate an airliner following a crash or cabin fire. FAA has
    taken seven key regulatory actions to improve fire detection, eliminate
    potential fire hazards, prevent the spread of fires, and better extinguish
    them. For example, to help prevent the spread of fire and give passengers
    more time to escape, FAA upgraded fire safety standards to require that
    seat cushions have fire-blocking layers, which resulted in airlines
    retrofitting 650,000 seats over a 3-year period. The agency also set new
    low heat/smoke standards for materials used for large interior surfaces
    (e.g., sidewalls, ceilings, and overhead bins), which FAA officials told
    us resulted in a significant improvement in postcrash fire survivability.
    FAA also required smoke detectors to be placed in lavatories and automatic
    fire extinguishers in lavatory waste receptacles in 1986 and 1987,
    respectively. In addition, the

    agency required airlines to retrofit their fleets with fire detection and
    suppression systems in cargo compartments, which according to FAA, applied
    to over 3,700 aircraft at a cost to airlines of $300 million. To better
    extinguish fires when they do start, FAA also required, in 1985, that
    commercial airliners carry two Halon fire extinguishers in addition to
    other required extinguishers because of Halon's superior fire suppression
    capabilities.

    We also identified 8 key advancements that are currently available and
    awaiting implementation or are under development to provide additional
    fire protection for cabin occupants in the future. Examples include the
    following:

    o 	Reduced flammability of insulation materials: To eliminate a potential
    fire hazard, in May 2000, FAA required that air carriers replace
    insulation blankets covered with a type of insulation known as metalized
    Mylar(R) on specific aircraft by 2005, after it was found that the
    material had ignited and contributed to the crash of Swiss Air Flight
    111.7 Over 700 aircraft were affected by this requirement. In addition,
    FAA issued a rule in July 2003 requiring that large commercial airplanes
    manufactured after September 2, 2005, be equipped with thermal acoustic
    insulation designed to an upgraded fire test standard that will reduce the
    incidence and intensity of in-flight fires. In addition, after September
    2, 2007, newly manufactured aircraft must be equipped with thermal
    acoustic materials designed to meet a new standard for burn-through
    resistance, providing passengers more time to escape during a postcrash
    fire.

    o 	Reduced fuel tank flammability: Flammable vapors in aircraft fuel tanks
    can ignite. However, currently available technology can greatly reduce
    this hazard by "blanketing" the fuel tank with nonexplosive
    nitrogen-enriched air to suppress ("inert") the potential for explosion of
    the tank. The U.S. military has used this technology on selected aircraft
    for 20 years, but U.S. commercial airlines have not adopted the technology
    because of its cost and weight. FAA officials told us that the military's
    technology was also unreliable and designed to meet military rather than
    civilian airplane design requirements. FAA fire safety experts have
    developed a lighter-weight inerting system for center fuel tanks, which is
    simpler than the military system and potentially more

    7Affected aircraft included Boeing MD-80, MD-88, MD-90, DC-10, and MD-11.

    reliable. Reliability of this technology is a major concern for the
    aviation industry. According to FAA officials, Boeing and Airbus began
    flight testing this technology in July 2003 and August 2003,
    respectively.8 In addition, the Air Transport Association (ATA) noted that
    inerting is only one prospective component of an ongoing major program for
    fuel tank safety, and that it has yet to be justified as feasible and
    cost-effective.

    o 	Sensor technology: Sensors are currently being developed to better
    detect overheated or burning materials. According to FAA and the National
    Institute of Standards and Technology, many current smoke and fire
    detectors are not reliable. For example, a recent FAA study reported at
    least one false alarm per week in cargo compartment fire detection
    systems. The new detectors are being developed by Airbus and others in
    private industry to reduce the number of false alarms. In addition, FAA is
    developing standards that would be used to approve new, reduced false
    alarm sensors. NASA is also developing new sensors and detectors.

    o 	Water mist for extinguishing fires: Technology has been under
    development for over two decades to dispense water mist during a fire to
    protect passengers from heat and smoke and prevent the spread of fire in
    the cabin. The most significant development effort has been made by a
    European public-private consortium, FIREDETEX, with over 5 million euros
    of European Community funding and a total project cost of over 10 million
    euros (over 10 million U.S. dollars). The development of this system was
    prompted, in part, by the need to replace Halon, when it was determined
    that this main firefighting agent used in fire extinguishers aboard
    commercial airliners depletes ozone in the atmosphere.

    Appendix V contains additional information on advancements that address
    fire prevention and mitigation.

    Improving the Chances and Enabling passengers to evacuate more quickly
    during an emergency has

    Speed of Evacuation	saved lives. Over the past two decades, FAA has
    completed regulatory action on the following six key requirements to help
    speed evacuations:

    8According to FAA, Boeing is flight testing a system similar to the FAA
    design, and Airbus is flight testing the FAA system in an A320. Boeing
    announced that it would begin installing inerting systems similar to the
    FAA design in their 747s in 2005.

    o 	Improve access to certain emergency exits, such as those generally
    smaller exits above the wing, by providing an unobstructed passageway to
    the exit.

    o 	Install public address systems that are independently powered and can
    be used for at least 10 minutes.

    o 	Help to ensure that passengers in the seats next to emergency exits are
    physically and mentally able to operate the exit doors and assist other
    passengers in emergency evacuations.

    o  Limit the distance between emergency exits to 60 feet.

    o 	Install emergency lighting systems that visually identify the emergency
    escape path and each exit.

    o  Install fire-resistant emergency evacuation slides.

    We also identified 10 advancements that are either currently available but
    awaiting implementation or require additional research that could lead to
    improved aircraft evacuation, including the following:

    o 	Improved passenger safety briefings: Information is available to the
    airlines on how to develop more appealing safety briefings and safety
    briefing cards so that passengers would be more likely to pay attention to
    the briefings and be better prepared to evacuate successfully during an
    emergency. Research has found that passengers often ignore the oral
    briefings and do not familiarize themselves with the safety briefing
    cards. FAA has requested that air carriers explore different ways to
    present safety information to passengers, but FAA regulates only the
    content of briefings. The presentation style of safety briefings is left
    up to air carriers.

    o 	Over-wing exit doors: Exit doors located over the wings of some
    commercial airliners have been redesigned to "swing out" and away from the
    aircraft so that cabin occupants can exit more easily during an emergency.
    Currently, the over-wing exit doors on most U.S. commercial airliners are
    "self help" doors and must be lifted and stowed by a passenger, which can
    impede evacuation. (See fig. 2.) The redesigned doors are now used on
    new-generation B-737 aircraft operated by one U.S. and most European
    airlines. FAA does not currently require the use of over-wing exit doors
    that swing out because the exit doors that are

    removed manually meet the agency's safety standards. However, FAA is
    working with the Europeans to develop common requirements for the use of
    this type of exit door.

    o 	Audio attraction signals: The United Kingdom's Civil Aviation Authority
    and the manufacturer are testing audio attraction signals to determine
    their usefulness to passengers in locating exit doors during an
    evacuation. These signals would be mounted near exits and activated during
    an emergency. The signals would help the passengers find the nearest exit
    even if lighting and exit signs were obscured by smoke.

    Figure 2: Manual "Self Help" and "Swing Out" Over-Wing Exits

    Appendix VI contains additional information on advancements to improve
    aircraft emergency evacuations.

    Improving the Safety and Passengers and flight attendants can face a range
    of safety and health

    Health of Cabin Occupants 	effects while aboard commercial airliners. We
    identified three key actions taken by FAA to help maintain the safety and
    health of passengers and the

    cabin crew during normal flight operations.9 For example, to prevent
    passengers from being injured during turbulent conditions, FAA initiated
    the Turbulence Happens campaign in 2000 to increase public awareness of
    the importance of wearing seatbelts. The agency has advised the airlines
    to warn passengers to fasten their seatbelts when turbulence is expected,
    and the airlines generally advise or require passengers to keep their seat
    belts fastened while seated to help avoid injuries from unexpected
    turbulence. FAA has also required the airlines to equip their fleets with
    emergency medical kits since 1986. In addition, Congress banned smoking on
    most domestic flights in 1990.

    We also identified five advancements that are either currently available
    but awaiting implementation or require additional research that could lead
    to an improvement in the health of passengers and flight attendants in the
    future.

    o 	Automatic external defibrillators: Automatic external defibrillators
    are currently available for use on some commercial airliners if a
    passenger or crew member requires resuscitation. In 1998, the Congress
    directed FAA to assess the need for the defibrillators on commercial
    airliners. On the basis of its findings, the agency issued a rule
    requiring that U.S. airlines equip their aircraft with automatic external
    defibrillators by 2004. According to ATA, most airlines have already done
    so.

    o 	Enhanced emergency medical kits: In 1998, the Congress directed FAA to
    collect data for 1 year on the types of in-flight medical emergencies that
    occurred to determine if existing medical kits should be upgraded. On the
    basis of the data collected, FAA issued a rule that required the contents
    of existing emergency medical kits to be expanded to deal with a broader
    range of emergencies. U.S. commercial airliners are required to carry
    these enhanced emergency medical kits by 2004. Most U.S. airlines have
    already completed this upgrade, according to ATA.

    o 	Advance warning of turbulence: New airborne weather radar and other
    technologies are currently being developed and evaluated to improve the
    detection of turbulence and increase the time available to cabin occupants
    to avert potential injuries. FAA's July 2003 draft strategic plan
    established a performance target of reducing injuries to cabin occupants
    caused by turbulence. To achieve this objective, FAA plans to continue

    9As noted, actions taken to improve cabin air quality will be discussed in
    another report.

    evaluating new airborne weather radars and other technologies that broadly
    address weather issues, including turbulence. In addition, the draft
    strategic plan set a performance target of reducing serious injuries
    caused by turbulence by 33 percent by fiscal year 2008--using the average
    for fiscal years 2000 through 2002 of 15 injuries per year as the baseline
    and reducing this average to no more than 10 per year.

    o 	Improve awareness of radiation exposure: Flight attendants and
    passengers who fly frequently can be exposed to higher levels of radiation
    on a cumulative basis than the general public. High levels of radiation
    have been linked to an increased risk of cancer and potential harm to
    fetuses. To help passengers and crew members estimate their past and
    future radiation exposure levels, FAA developed a computer model, which is
    publicly available on its Web site
    http://www.jag.cami.jccbi.gov/cariprofile.asp. However, the extent to
    which flight attendants and frequent flyers are aware of cosmic
    radiation's risks and make use of FAA's computer model is unclear. Agency
    officials told us that they plan to install a counter capability on its
    Civil Aerospace Medical Institute Web site to track the number of visits
    to its aircrew and passenger health and safety Web site. FAA also plans to
    issue an Advisory Circular by early next year, which incorporates the
    findings of a just completed FAA report, "What Aircrews Should Know About
    Their Occupational Exposure to Ionizing Radiation." This Advisory Circular
    will include recommended actions for aircrews and information on solar
    flare event notification of aircrews. In contrast, airlines in Europe
    abide by more stringent requirements for helping to ensure that cabin and
    flight crew members do not receive excessive doses of radiation from
    performing their flight duties during a given year. For example, in May
    1996, the European Union issued a directive for workers, including air
    carrier crew members (cabin and flight crews) and the general public, on
    basic safety and health protections against dangers arising from ionizing
    radiation. This directive set dose limits and required air carriers to (1)
    assess and monitor the exposure of all crew members to avoid exceeding
    exposure limits, (2) work with those individuals at risk of high exposure
    levels to adjust their work or flight schedules to reduce those levels,
    and (3) inform crew members of the health risks that their work involves
    from exposure to radiation. It also required airlines to work with female
    crew members, when they announce a pregnancy, to avoid exposing the fetus
    to harmful levels of radiation. This directive was binding for all
    European Union member states and became effective in May 2000.

    o 	Improved awareness of potential health effects related to flying: Air
    travel may exacerbate some medical conditions. Of particular concern is a
    condition known as Deep Vein Thrombosis (DVT), or travelers' thrombosis,
    in which blood clots can develop in the deep veins of the legs from
    extended periods of inactivity. In a small percentage of cases, the clots
    can break free and travel to the lungs, with potentially fatal results.
    Although steps can be taken to avoid or mitigate some travel-related
    health effects, no formal awareness campaigns have been initiated by FAA
    to help ensure that this information reaches physicians and the traveling
    public. The Aerospace Medical Association's Web site
    http://www.asma.org/publication.html includes guidance for physicians to
    use in advising passengers with preexisting medical conditions on the
    potential risks of flying, as well as information for passengers with such
    conditions to use in assessing their own potential risks.

    See appendix VII for additional information on health-related advances.

    Advancements Vary in Their Readiness for Deployment

    The advancements being pursued to improve the safety and health of cabin
    occupants vary in their readiness for deployment. For example, of the 28
    advancements we reviewed, 14 are mature and currently available. Two of
    these, preparation for in-flight medical emergencies and the use of new
    insulation, were addressed through regulations. These regulations require
    airlines to install additional emergency medical equipment (automatic
    external defibrillators and enhanced emergency medical kits) by 2004,
    replace flammable insulation covering (metalized Mylar(R)) on specific
    aircraft by 2005, and manufacture new large commercial airliners that use
    a new type of insulation meeting more stringent flammability test
    standards after September 2, 2005. Another advancement is currently in the
    rule-making process-retrofitting the existing fleet with stronger 16g
    seats. The remaining 11 advancements are available, but are not required
    by FAA. For example, some airlines have elected to use inflatable lap seat
    belts and exit doors over the wings that swing out instead of requiring
    manual removal, and others are using photo-luminescent floor lighting in
    lieu of or in combination with traditional electrical lighting. Some of
    these advancements are commercially available to the flying public,
    including smoke hoods and child safety seats certified for use on
    commercial airliners. The remaining 14 advancements are in various stages
    of research, engineering, and development in the United States, Canada, or
    Europe.

    Several Factors Have Slowed the Implementation of Cabin Occupant Safety
    and Health Advancements

    Several factors have slowed the implementation of airliner cabin occupant
    safety and health advancements in the United States. When advancements are
    available for commercial use but not yet implemented or installed, their
    use may be slowed by the time it takes (1) for FAA to complete the
    rule-making process,10 which may be required for an advancement to be
    approved for use but may take many years; (2) for U.S. and foreign
    aviation authorities to resolve differences between their respective cabin
    occupant safety and health requirements; and (3) for the airlines to adopt
    or install advancements after FAA has approved their use, including the
    time required to schedule an advancement's installation to coincide with
    major maintenance cycles and thereby minimize the costs associated with
    taking an airplane out of service. When advancements are not ready for
    commercial use because they need further research to develop their
    technologies or reduce their costs, their implementation may be slowed by
    FAA's multistep process for identifying advancements and allocating its
    limited resources to research on potential advancements. FAA's multistep
    process is hampered by a lack of autopsy and survivor information from
    past accidents and by not having cost and effectiveness data as part of
    the decision process. As a result, FAA may not be identifying and funding
    the most critical or cost-effective research projects.

    FAA's Rule-making Process to Require Advancements Can Be Lengthy

    Once an advancement has been developed, FAA may require its use, but
    significant time may be required before the rule-making process is
    complete. One factor that contributes to the length of this process is a
    requirement for cost-benefit analyses to be completed. Time is
    particularly important when safety is at stake or when the pace of
    technological development exceeds the pace of rule-making. As a result,
    some rules may need to be developed quickly to address safety issues or to
    guide the use of new technologies. However, rules must also be carefully
    considered before being finalized because they can have a significant
    impact on individuals, industries, the economy, and the environment.
    External pressures-such as political pressure generated by highly
    publicized accidents, recommendations by NTSB, and congressional
    mandates-as well as internal pressures, such as changes in management's
    emphasis, continue to add to and shift the agency's priorities.

    10ATA noted that, for those technologies that are ready, FAA must develop
    design and certification standards before undertaking the rule-making
    process to require their implementation.

    The rule-making process can be long and complicated and has delayed the
    implementation of some technological and operational safety improvements,
    as we reported in July 2001.11 In that report, we reviewed 76 significant
    rules in FAA's workload for fiscal years 1995 through 2000-10 of the 76
    were directly related to improving the safety and health of cabin
    occupants.12 Table 3 details the status or disposition of these 10 rules.
    The shortest rule-making action took 1 year, 11 months (for child
    restraint systems), and the longest took 10 years, 1 month (for the type
    and number of emergency exits). However, one proposed rule was still
    pending after 15 years, while three others were terminated or withdrawn
    after 9 years or more. Of the 76 significant rules we reviewed, FAA
    completed the rule-making process for 29 of them between fiscal year 1995
    and fiscal year 2000, in a median time of about 2  1/2 years to proceed
    from formal initiation of the rule-making process through publication of
    the final rule; however, FAA took 10 years or more to move from formal
    initiation of the rule-making process through publication of the final
    rule for 6 of these 29 rules.

    Table 3: Status of 10 Significant FAA Rules Pertaining to Airliner Cabin
    Occupants' Safety and Health, Fiscal Year 1995 through September of Fiscal
    Year 2003

               Rule title         Initiation        Time    Status/disposition
                                    datea        elapsed
            Flight attendant         2/04/86  9 years, 8     Terminated/withdrawn
              requirements                        months                  6/06/96
           Type and number of                10 years, 1
    passenger emergency exits    10/15/86       month Final rule published on
         required in transport                                   11/08/96
           category airplanes
        Airworthiness standards;             11 years, 1
          occupant protection        5/29/87       month   Terminated/withdrawn
         standards for commuter                                  6/30/98
           category airplanes
    Retrofit of improved seats            15 years, 6
        in air carrier transport     1/26/88      months         Pending
           category airplanes
                                              5 years, 9
        Child restraint systems      5/30/90      months   Terminated/withdrawn
                                                                 2/13/96

    11U.S. General Accounting Office, Aviation Rule-making: Further Reform Is
    Needed to Address Long-standing Problems, GAO-01-821 (Washington, D.C.:
    July 9, 2001).

    12Under Executive Order 12866, federal agencies and the Office of
    Management and Budget (OMB) categorize proposed and final rules in terms
    of their potential impact on the economy and the industry affected. The
    Order defines a regulatory action as "significant" if it, among other
    things, has an annual impact on the economy of $100 million or more and
    adversely affects the economy in a material way. To measure the overall
    impact of the 1998-rule-making reforms, through discussions with FAA
    officials, we created a database of 76 significant rules. These rules
    constituted the majority (about 83 percent) of FAA's significant rule
    workload from fiscal year 1995 through fiscal year 2000.

    (Continued From Previous Page)

                Rule title          Initiation       Time   Status/disposition
                                      datea       elapsed
        Revised access to Type III             9 years, 5        Withdrawn
                  exits              10/30/92      months
                                                                  5/03/02
         Child restraint systems       7/18/94  1 year 11 Final rule published on
                                                   months         6/04/96
         Child restraint systems       4/07/97 6 years, 3         Pending
                                                   months
                                               2 years, 8
    Emergency medical equipment     10/5/98     months Final rule published on
                                                                  6/12/01
          Improved flammability
          standards for thermal                4 years, 7 Final rule published on
           acoustic insulation       12/04/98      months           July 31, 2003
          materials in transport
            category aircraft

    Source: GAO analysis of FAA data.

    Note: In commenting on a draft of this report, FAA noted that examining
    the years elapsed from the initiation date of the rule to disposition can
    be unfair to some actions and that many of the delays were not the fault
    of FAA.

    aInitiation dates were identified in FAA's rule-making information system
    as GAO reported in July 2001. This was the only source for data on the
    agency's internal milestones, including "initiation date."

    Differences in U.S. and Foreign Requirements Can Hamper Adoption of
    Advancements

    FAA and its international counterparts, such as the European Joint
    Aviation Authorities (JAA), impose a number of requirements to improve
    safety. At times, these requirements differ, and efforts are needed to
    reach agreement on procedures and equipment across country borders. In the
    absence of such agreements, the airlines generally must adopt measures to
    implement whichever requirement is more stringent. In 1992, FAA and JAA
    began harmonizing their requirements for (1) the design, manufacture,
    operation, and maintenance of civil aircraft and related product parts;
    (2) noise and emissions from aircraft; and (3) flight crew licensing.
    Harmonizing the U.S. Federal Aviation Regulations with the European Joint
    Aviation Regulations is viewed by FAA as its most comprehensive long-term
    rule-making effort and is considered critical to ensuring common safety
    standards and minimizing the economic burden on the aviation industry that
    can result from redundant inspection, evaluation, and testing
    requirements.

    According to both FAA and JAA, the process they have used to date to
    harmonize their requirements for commercial aircraft has not effectively
    prioritized their joint recommendations for harmonizing U.S. and European
    aviation requirements, and led to many recommendations going unpublished
    for years. This includes a backlog of over 130 new rule-making efforts.
    The slowness of this process led the United States and Europe to develop a
    new rule-making process to prioritize safety initiatives, focus the
    aviation industry's and their own limited resources, and establish
    limitations on rule-making capabilities. Accordingly, in March 2003, FAA

    and JAA developed a draft joint "priority" rule-making list; collected and
    considered industry input; and coordinated with FAA's, JAA's, and
    Transport Canada Civil Aviation's management. This effort has resulted in
    a rule-making list of 26 priority projects. In June 2003, at the 20th
    Annual JAA/FAA International Conference, FAA, JAA, and Transport Canada
    Civil Aviation discussed the need to, among other things, support the
    joint priority rule-making list and to establish a cycle for updating
    it-to keep it current and to provide for "pop-up," or unexpected,
    rule-making needs. FAA and JAA discussed the need to prioritize
    rule-making efforts to efficiently achieve aviation safety goals; that
    they would work from a limited agreed-upon list for future rule-making
    activities; and that FAA and the European Aviation Safety Agency, which is
    gradually replacing JAA, should continue with this approach.

    In the area of cabin occupant safety and heath, some requirements have
    been harmonized, while others have not. For example, in 1996, JAA changed
    its rule on floor lighting to allow reflective, glow-in-the-dark material
    to be used rather than mandating the electrically powered lighting that
    FAA required. The agency subsequently permitted the use of this material
    for floor lighting. In addition, FAA finalized a rule in July 2003 to
    require a new type of insulation designed to delay fire burning though the
    fuselage into the cabin during an accident. JAA favors a performance-based
    standard that would specify a minimum delay in burn-through time, but
    allow the use of different technologies to achieve the standard. FAA
    officials said that the agency would consider other technologies besides
    insulation to achieve burn-through protection but that it would be the
    responsibility of the applicant to demonstrate that the technology
    provided performance equivalent to that stipulated in the insulation rule.
    JAA officials told us that these are examples of the types of issues that
    must be resolved when they work to harmonize their requirements with
    FAA's. These officials added that this process is typically very time
    consuming and has allowed for harmonizing about five rules per year.

    Significant Time May Be Needed to Implement Advancements Once They Are
    Required, but Some May Enhance Airlines' Competitiveness

    After an advancement has been developed, shown to be beneficial,
    certified, and required by FAA, the airlines or manufacturers need time to
    implement or install the advancement.13 FAA generally gives the airlines
    or manufacturers a window of time to comply with its rules. For example,
    FAA gave air carriers 5 years to replace metalized Mylar(R) insulation on
    specific aircraft with a less flammable insulation type, and FAA's
    proposed rule-making on 16g seats would give the airlines 14 years to
    install these seats in all existing commercial airliners. ATA officials
    told us that this would require replacement of 496,000 seats.

    The airline industry's recent financial hardships may also delay the
    adoption of advancements. Recently, two major U.S. carriers filed for
    bankruptcy,14 and events such as the war in Iraq have reduced passenger
    demand and airline revenues below levels already diminished by the events
    of September 11, 2001, and the economic downturn. Current U.S. demand for
    air travel remains below fiscal year 2000 levels. As a result, airlines
    may ask for exemptions from some requirements or extensions of time to
    install advancements.

    While implementing new safety and health advancements can be costly for
    the airlines, making these changes could improve the public's confidence
    in the overall safety of air travel. In addition, some aviation experts in
    Europe told us that health-related cabin improvements, particularly
    improvements in air quality, are of high interest to Europeans and would
    likely be used in the near future by some European air carriers to set
    themselves apart from their competitors.

    13According to ATA, even if a technology is available in the marketplace,
    it may not be adopted by the airlines until it has been certified by
    FAA--ensuring that "improvements" do not inadvertently compromise overall
    safety of the aircraft.

    14One of these U.S. carriers is no longer in bankruptcy.

    FAA's Multistep Process for Allocating Limited Resources to Research
    Projects Is Hampered by Lack of Autopsy and Survivor Information and Cost
    and Effectiveness Data

    Federal Research on Aircraft Cabin Occupant Safety and Health Issues

    For fiscal year 2003, FAA and NASA allocated about $16.2 million to cabin
    occupant safety and health research. FAA's share of this research
    represented $13.1 million, or about 9 percent of the agency's Research,
    Engineering, and Development budget of $148 million for fiscal year 2003.
    Given the level of funding allocated to this research effort, it is
    important to ensure that the best research projects are selected. However,
    FAA's processes for setting research priorities and selecting projects for
    further research are hampered by data limitations. In particular, FAA
    lacks certain autopsy and survivor information from aircraft crashes that
    could help it identify and target research to the most important causes of
    death and injury in an airliner crash. In addition, for the proposed
    research projects, the agency does not (1) develop comparable cost data
    for potential advancements or (2) assess their potential effectiveness in
    minimizing injuries or saving lives. Such cost and effectiveness data
    would provide a valuable supplement to FAA's current process for setting
    research priorities and selecting projects for funding.

    Both FAA and NASA conduct research on aircraft cabin occupant safety and
    health issues. The Civil Aeromedical Institute (CAMI) and the Hughes
    Technical Center are FAA's primary facilities for conducting research in
    this area. In addition, two facilities at NASA, the Langley and Glenn
    research centers, have also conducted research in this area. As figure 3
    shows, federal funding for this research since fiscal year 2000, reached a
    high in fiscal year 2002, at about $17 million, and fell to about $16.2
    million in fiscal year 2003. The administration's proposal for fiscal year
    2004 calls for a further reduction to $15.9 million. This funding covers
    the expenses of researchers at these facilities and of the contracts they
    may have with others to conduct research. In addition, NASA recently
    decided to end its crash research at Langley and to close a drop test
    facility that it operates in Hampton, Virginia.

    Figure 3: Funding for Federal Research on Cabin Occupant Safety and Health
    Issues, by Facility, Fiscal Years 2000-2005

    Note: FAA Hughes Technical Center data includes work in fire-safe fuels,
    fuel-tank inerting, arc fault circuit breakers, and airport rescue and
    fire-fighting operations.

    In fiscal year 2003, FAA and NASA both supported research projects,
    including aircraft impact, fire, evacuation, and health. As figure 4
    shows, most of the funding for cabin occupant safety and health research
    has gone to fire-related projects.

    FAA Research Selection Process Hampered by Lack of Autopsy and Survivor
    Information and Cost and Effectiveness Analyses

    Figure 4: Allocation of Federal Funding for Aircraft Cabin Occupant Safety
    and Health Research, Fiscal Year 2003

    Note: Sum of bars exceeds $16.2 million due to rounding. FAA Technical
    Center data includes work in fire-safe fuels, fuel-tank inerting, arc
    fault circuit breakers, and airport rescue and fire-fighting operations

    To establish research priorities and select projects to fund, FAA uses a
    multistep process. First, within each budget cycle, a number of Technical
    Community Representative Group subcommittees from within FAA generate
    research ideas. Various subcommittees have responsibility for identifying
    potential safety and health projects, including subcommittees on crash
    dynamics, fire safety, structural integrity, passenger evacuation,
    aeromedical, and fuel safety. Each subcommittee proposes research projects
    to review committees, which prioritize the projects. The projects are
    considered and weighted according to the extent to which they address (1)
    accident prevention, (2) accident survival, (3) external requests for
    research, (4) internal requests for research, and (5) technology research
    needs. In addition, the cost of the proposed research is considered before
    arriving at a final list of projects. The prioritized list is then
    considered by the Program Planning Team, which reviews the projects from a
    policy perspective.

    Although the primary causes of death and injury in commercial airliner
    crashes are known to be impact, fire, and impediments to evacuation, FAA
    does not have as detailed an understanding as it would like of the
    critical factors affecting survival in a crash. According to FAA
    officials, obtaining a more detailed understanding of these factors would
    assist them in setting research priorities and in evaluating the relative
    importance of competing research proposals. To obtain a more detailed
    understanding of the critical factors affecting survival, FAA believes
    that it needs additional information from passenger autopsies and from
    passengers who survived. With this information, FAA could then regulate
    safety more effectively, airplane and equipment designers could build
    safer aircraft, including cabin interiors, and more passengers could
    survive future accidents as equipment became safer.

    While FAA has independent authority to investigate commercial airliner
    crashes, NTSB generally controls access to the accident investigation site
    in pursuit of its primary mission of determining the cause of the crash.
    When NTSB concludes its investigation, it returns the airplane to its
    owner and keeps the records of the investigation, including the autopsy
    reports and the information from survivors that NTSB obtains from medical
    authorities and through interviews or questionnaires. NTSB makes summary
    information on the crashes publicly available on its Web site, but
    according to the FAA researchers, this information is not detailed enough
    for their needs. For example, the researchers would like to develop a
    complete autopsy database that would allow them to look for common trends
    in accidents, among other things. In addition, the researchers would like
    to know where survivors sat on the airplane, what routes they took to
    exit, what problems they encountered, and what injuries they sustained.
    This information would help the researchers analyze factors that might
    have an impact on survival. According to the NTSB's Chief of the Survival
    Factors Division in the Office of Aviation Safety, NTSB provides
    information on the causes of death and a description of injuries in the
    information they make publicly available. In addition, although medical
    records and autopsy reports are not made public, interviews with and
    questionnaires from survivors are available from the public docket.

    NTSB's Medical Officer was unaware of any formal requests from the FAA for
    the NTSB to provide them with copies of this type of information, although
    the FAA had previously been invited to review such information at NTSB
    headquarters. He added that the Board would likely consider a formal
    request from FAA for copies of autopsy reports and certain survivor
    records, but that it was also likely that the FAA would have to assure
    NTSB

    that the information would be appropriately safeguarded. According to FAA
    officials, close cooperation between the NTSB and the FAA is needed for
    continued progress in aviation safety.

    Besides lacking detailed information on the causes of death and injury,
    FAA does not develop data on the cost to implement advancements that are
    comparable for each, nor does it assess the potential effectiveness of
    each advancement in reducing injuries and saving lives. Specifically, FAA
    does not conduct cost-benefit analyses as part of its multistep process
    for setting research priorities. Making cost estimates of competing
    advancements would allow direct comparisons across alternatives, which,
    when combined with comparable estimates of effectiveness, would provide
    valuable supplemental information to decision makers when setting research
    priorities. FAA considers its current process to be appropriate and
    sufficient. In commenting on a draft of this report, FAA noted that it is
    very difficult to develop realistic cost data for advancements during the
    earliest stages of research. The agency cautioned that if too much
    emphasis is placed on cost/benefit analyses, potentially valuable research
    may not be undertaken. Recognizing that it is less difficult to develop
    cost and effectiveness information as research progresses, we are
    recommending that FAA develop and use cost and effectiveness analyses to
    supplement its current process. At later stages in the development
    process, we found that this information can be developed fairly easily
    through cost and effectiveness analyses using currently available data.
    For example, we performed an analysis of the cost to implement inflatable
    lap seat belts using a cost analysis methodology we developed (see app.
    VIII). This analysis allowed us to estimate how much this advancement
    would cost per airplane and per passenger trip. Such cost analyses could
    be combined with similar analyses of effectiveness to identify the most
    cost-effective projects, based on their potential to minimize injuries and
    reduce fatalities. Potential sources of effectiveness data include FAA,
    academia, industry, and other aviation authorities.

    Conclusions 	Although FAA and the aviation community are pursuing a number
    of advancements to enhance commercial airliners' cabin occupant safety and
    health, several factors have slowed their implementation. For example, for
    advancements that are currently available but are not yet implemented or
    installed, progress is slowed by the length of time it takes for FAA to
    complete its rule-making process, for the U.S and foreign countries to
    agree on the same requirements, and for the airlines to actually install
    the advancements after FAA has required them. In addition, FAA's multistep

    process for identifying potential cabin occupant safety and health
    research projects and allocating its limited research funding is hampered
    by the lack of autopsy and survivor information from airliner crashes and
    by the lack of cost and effectiveness analysis. Given the level of funding
    allocated to cabin occupant safety and health research, it is important
    for FAA to ensure that this funding is targeting the advancements that
    address the most critical needs and show the most promise for improving
    the safety and health of cabin occupants. However, because FAA lacks
    detailed autopsy and survivor information, it is hampered in its ability
    to identify the principal causes of death and survival in commercial
    airliner crashes. Without an agreement with the National Transportation
    Safety Board (NTSB) to receive detailed autopsy and survivor information,
    FAA lacks information that could be helpful in understanding the factors
    that contribute to surviving a crash. Furthermore, because FAA does not
    develop comparable estimates of cost and effectiveness of competing
    research projects, it cannot ensure that it is funding those technologies
    with the most promise of saving lives and reducing injuries. Such cost and
    effectiveness data would provide a valuable supplement to FAA's current
    process for setting research priorities and selecting projects for
    funding. To facilitate FAA's development of comparable cost data across
    advancements, we developed a cost analysis methodology that could be
    combined with a similar analysis of effectiveness to identify the most
    cost-effective projects. Using comparable cost and effectiveness data
    across the range of advancements would position the agency to choose more
    effectively between competing advancements, taking into account estimates
    of the number of injuries and fatalities that each advancement might
    prevent for the dollars invested. In turn, FAA would have more assurance
    that the level of funding allocated to this effort maximizes the safety
    and health of the traveling public and the cabin crew members who serve
    them.

    Recommendations for Executive Action

    To provide FAA decision makers with additional data for use in setting
    priorities for research on cabin occupant safety and health and in
    selecting competing research projects for funding, we recommend that the
    Secretary of Transportation direct the FAA Administrator to

    o 	initiate discussions with the National Transportation Safety Board in
    an effort to obtain the autopsy and survivor information needed to more
    fully understand the factors affecting survival in a commercial airliner
    crash and

    o 	supplement its current process by developing and using comparable
    estimates of cost and effectiveness for each cabin occupant safety and
    health advancement under consideration for research funding.

    Agency Comments and 	We provided copies of a draft of this report to the
    Department of Transportation for its review and comment. FAA generally
    agreed with the

    Our Evaluation	report's contents and its recommendations. The agency
    provided us with oral comments, primarily technical clarifications, which
    we have incorporated as appropriate.

    As agreed with your office, unless you publicly announce its contents
    earlier, we plan no further distribution of this report until 10 days
    after the
    date of this letter. At that time, we will send copies to the appropriate
    congressional committees; the Secretary of Transportation; the
    Administrator, FAA; and the Chairman, NTSB. We will also make copies
    available to others upon request. In addition, this report is also
    available at
    no charge on GAO's Web site at http://www.gao.gov.

    Contacts and staff acknowledgements for this report are included in
    appendix IX. If you or your staff have any questions, please contact me or
    Glen Trochelman at (202) 512-2834

    Sincerely yours,

    Gerald L. Dillingham
    Director, Physical Infrastructure Issues

    Appendix I

                           Objectives, Scope, and Methodology

    As requested by the Ranking Democratic Member, House Committee on
    Transportation and Infrastructure, we addressed the following questions:
    (1) What regulatory actions has the Federal Aviation Administration (FAA)
    taken, and what key advancements are available or being developed by FAA
    and others to address safety and health issues faced by passengers and
    flight attendants in large commercial airliner cabins? (2) What factors,
    if any, slow the implementation of advancements in cabin occupant safety
    and health? In addition, as requested, we identified some factors
    affecting efforts by Canada and Europe to improve cabin occupant safety
    and health.

    The scope of our report includes the cabins of large commercial aircraft
    (those that carry 30 or more passengers) operated by U.S. domestic
    commercial airlines and addresses the safety and health of passengers and
    flight attendants from the time they board the airliner until they
    disembark under normal operational conditions or emergency situations.
    This report identifies cabin occupant safety and health advancements
    (technological or operational improvements) that could be implemented,
    primarily through FAA's rule-making process. Such improvements include
    technological changes designed to increase the overall safety of
    commercial aviation as well as changes to enhance operational safety. The
    report does not include information on the flight decks of large
    commercial airliners or safety and health issues affecting flight deck
    crews (pilots and flight engineers), because they face some issues not
    faced by cabin occupants. It also does not address general aviation and
    corporate aircraft or aviation security issues, such as hijackings,
    sabotage, or terrorist activities.

    To identify regulatory actions that FAA has taken to address safety and
    health issues faced by passengers and flight attendants in large
    commercial airliner cabins, we interviewed and collected documentation
    from U.S. federal agency officials on major safety and health efforts
    completed by FAA. The information we obtained included key dates and
    efforts related to cabin occupant safety and health, such as rule-makings,
    airworthiness directives, and Advisory Circulars.

    To identify key advancements that are available or are being developed by
    FAA and others to address safety and health issues faced by passengers and
    flight attendants in large commercial airliner cabins, we consulted
    experts (1) to help ensure that we had included the advancements holding
    the most promise for improving safety and health; and (2) to help us
    structure an evaluation of selected advancements (i.e., confirm that we
    had included the critical benefits and drawbacks of the potential
    advancements) and develop a descriptive analysis for them, where
    appropriate, including their

    Appendix I
    Objectives, Scope, and Methodology

    benefits, costs, technology readiness levels, and regulatory status. In
    addition, we interviewed and obtained documentation from federal agency
    officials and other aviation safety experts at the Federal Aviation
    Administration (including its headquarters in Washington, D.C.; Transport
    Airplane Directorate in Renton, Washington; William J. Hughes Technical
    Center in Atlantic City, New Jersey; and Mike Monroney Aeronautical
    Center/Civil Aerospace Medical Institute in Oklahoma City, Oklahoma);
    National Transportation Safety Board; National Aeronautics and Space
    Administration (NASA); Air Transport Association; Regional Airline
    Association; International Air Transport Association; Aerospace Industries
    Association; Aerospace Medical Association; Flight Safety Foundation,
    Association of Flight Attendants; Boeing Commercial Airplane Group;
    Airbus; Cranfield University, United Kingdom; University of Greenwich,
    United Kingdom; National Aerospace Laboratory, Netherlands; Joint Aviation
    Authorities, Netherlands; Civil Aviation, Netherlands; Civil Aviation
    Authority, United Kingdom; RGW Cherry and Associates; Air Accidents
    Investigations Branch, United Kingdom; Syndicat National du Personnel
    Navigant Commercial (French cabin crew union) and ITF Cabin Crew
    Committee, France; BEA (comparable to the U.S. NTSB), France; and the
    Direction Generale de l'Aviation Civile (DGAC), FAA's French counterpart.

    To describe the status of key advancements that are available or under
    development, we used NASA's technology readiness levels (TRL). These
    levels form a system for ranking the maturity of particular technologies
    and are as follows:

    o  TRL 1: Basic principles observed and reported

    o  TRL 2: Technology concept and/or application formulated

    o 	TRL 3: Analytical and experimental critical function and/or
    characteristic proof-of-concept developed

    o  TRL 4: Component validation in laboratory environment

    o  TRL 5: Component and/or validation in relevant environment

    o 	TRL 6: System or subsystem model or prototype demonstrated in a
    relevant environment

    o  TRL 7: System prototype demonstrated in a space environment

    Appendix I
    Objectives, Scope, and Methodology

    o 	TRL 8: Actual system completed and "flight qualified" through test and
    demonstration

    o 	TRL 9: Actual system "flight proven" through successful mission
    operations

    To determine what factors, if any, slow the implementation of advancements
    in cabin occupant safety and health, we reviewed the relevant literature
    and interviewed and analyzed documentation from the U.S. federal officials
    cited above for the 18 key regulatory actions FAA has taken since 1984 to
    improve the safety and health of cabin occupants. We used this same
    approach to assess the regulatory status of the 28 advancements we
    reviewed that are either currently available, but not yet implemented or
    installed, or require further research to demonstrate their effectiveness
    or lower their costs. In identifying 28 advancements, GAO is not
    suggesting that these are the only advancements being pursued; rather,
    these advancements have been recognized by aviation safety experts we
    contacted as offering promise for improving the safety and health of cabin
    occupants. To determine how long it generally takes for FAA to issue new
    rules, in addition to speaking with FAA officials, we relied on past GAO
    work and updated it, as necessary. In order to examine the effect of FAA
    and European efforts to harmonize their aviation safety requirements, we
    interviewed and analyzed documentation from aviation safety officials and
    other experts in the United States, Canada, and Europe. Furthermore, to
    examine the factors affecting airlines' ability to implement or install
    advancements after FAA requires them, we interviewed and analyzed
    documentation from aircraft manufacturers, ATA, and FAA officials.

    In addition, to determine what factors slow implementation we examined
    FAA's processes for selecting research projects to improve cabin occupant
    safety and health. In examining whether FAA has sufficient data upon which
    to base its research priorities, we interviewed FAA and National
    Transportation Safety Board (NTSB) officials about autopsy and survivor
    information from commercial airliner accidents. We also examined the use
    of cost and effectiveness data in FAA's research selection process for
    cabin occupant safety and health projects. To facilitate FAA's development
    of such cost estimates, we developed a cost analysis methodology to
    illustrate how the agency could do this. Specifically, we developed a cost
    analysis for inflatable lap belts to show how data on key cost variables
    could be obtained from a variety of sources. We selected lap belts because
    they were being used in limited situations and appeared to offer some
    measure of improved safety. Information on installation price, annual
    maintenance and

    Appendix I
    Objectives, Scope, and Methodology

    refurbishment costs, and added weight of these belts was obtained from
    belt manufacturers. We obtained information from FAA and the Department of
    Transportation's (DOT) Bureau of Transportation Statistics on a number of
    cost variables, including historical jet fuel prices, the impact on jet
    fuel consumption of carrying additional weight, the average number of
    hours flown per year, the average number of seats per airplane, the number
    of airplanes in the U.S. fleet, and the number of passenger tickets issued
    per year. To account for variation in the values of these cost variables,
    we performed a Monte Carlo simulation.1 In this simulation, values were
    randomly drawn 10,000 times from probability distributions characterizing
    possible values for the number of seat belts per airplane, seat
    installation price, jet fuel price, number of passenger tickets, number of
    airplanes, and hours flown. This simulation resulted in forecasts of the
    life-cycle cost per airplane, the annualized cost per airplane, and the
    cost per ticket. There is uncertainty in estimating the number of lives
    potentially saved and their value because accidents occur infrequently and
    unpredictably. Such estimates could be higher or lower, depending on the
    number and severity of accidents during a given analysis period and the
    value placed on a human life.

    To identify factors affecting efforts by Canada and Europe to improve
    cabin occupant safety and health we interviewed and collected
    documentation from aviation safety experts in the United States, Canada,
    and Europe.

    We provided segments of a draft of this report to selected external
    experts to help ensure its accuracy and completeness. These included the
    Air Transport Association, National Transportation Safety Board, Boeing,
    Airbus, and aviation authorities in the United Kingdom, France, Canada and
    the European Union. We incorporated their comments, as appropriate. The
    European Union did not provide comments.

    We conducted our review from January 2002 through September 2003 in
    accordance with generally accepted government auditing standards.

    1A Monte Carlo simulation is a widely used computational method for
    generating probability distributions of variables that depend on other
    variables or parameters represented as probability distributions.

    Appendix II

    Canada and Europe Cabin Occupant Safety and Health Responsibilities

    The United States, Canada, and members of the European Community are
    parties to the International Civil Aviation Organization (ICAO),
    established under the Chicago Convention of 1944, which sets minimum
    standards and recommended practices for civil aviation. In turn,
    individual nations implement aviation standards, including those for
    aviation safety. While ICAO's standards and practices are intended to keep
    aircraft, crews, and passengers safe, some also address environmental
    conditions in aircraft cabins that could affect the health of passengers
    and crews. For example, ICAO has standards for preventing the spread of
    disease and for spraying aircraft cabins with pesticides to remove
    disease-carrying insects.

    Canada	In Canada, FAA's counterpart for aviation regulations and oversight
    is Transport Canada Civil Aviation, which sets standards and regulations
    for the safe manufacture, operation, and maintenance of aircraft in
    Canada. In addition, Transport Canada Civil Aviation administers,
    enforces, and promotes the Aviation Occupational Health and Safety Program
    to help ensure the safety and health of crewmembers on board aircraft.1
    The department also sets the training and licensing standards for aviation
    professionals in Canada, including air traffic controllers, pilots, and
    aircraft maintenance engineers. Transport Canada Civil Aviation has more
    than 800 inspectors working with Canadian airline operators, aircraft
    manufacturers, airport operators, and air navigation service providers to
    maintain the safety of Canada's aviation system. These inspectors monitor,
    inspect, and audit Canadian aviation companies to verify their compliance
    with Transport Canada's aviation regulations and standards for pilot
    licensing, aircraft certification, and aircraft operation.

    To assess and recommend potential changes to Canada's aviation regulations
    and standards, the Canadian Aviation Regulation Advisory Council was
    established. This Council is a joint initiative between government and the
    aviation community. The Council supports regulatory meetings and technical
    working groups, which members of the aviation community can attend. A
    number of nongovernmental organizations- including airline operators,
    aviation labor organizations, manufacturers, industry associations, and
    groups representing the public-are members.

    1The Headquarters Division of Transport Canada provides guidance and
    assistance to Regional Civil Aviation Safety Inspectors - Occupational
    Health and Safety who conduct inspections, investigations, and promotional
    visits to ensure that airline operators are committed to the safety and
    health of their employees.

                                      Appendix II
                        Canada and Europe Cabin Occupant Safety
                              and Health Responsibilities

    The Transportation Safety Board (TSB) of Canada is similar to NTSB in the
    United States. TSB is a federal agency that operates independently of
    Transport Canada Civil Aviation. Its mandate is to advance safety in the
    areas of marine, pipeline, rail, and aviation transportation by

    o 	conducting independent investigations, including public inquiries when
    necessary, into selected transportation occurrences in order to make
    findings as to their causes and contributing factors;

    o 	identifying safety deficiencies, as evidenced by transportation
    occurrences;

    o 	making recommendations designed to reduce or eliminate any such
    deficiencies; and

    o  reporting publicly on their investigations and findings.

    Under its mandate to conduct investigations, TSB conducts
    safety-issue-related investigations and studies. It also maintains a
    mandatory incident-reporting system for all modes of transportation. TSB
    and Transport Canada Civil Aviation use the statistics derived from this
    information to track potential safety concerns in Canada's transportation
    system.

    TSB investigates aircraft accidents that occur in Canada or involve
    aircraft built there. Like NTSB, the Transportation Safety Board can
    recommend air safety improvements to Transport Canada Civil Aviation.

    Europe 	Europe supplements the ICAO framework with the European Civil
    Aviation Conference, an informal forum through which 38 European countries
    formulate policy on civil aviation issues, including safety, but do not
    explicitly address passenger health issues. In addition, the European
    Union issues legislation concerning aviation safety, certification, and
    licensing requirements but has not adopted legislation specifically
    related to passenger health. One European directive requires that all
    member states assess and limit crewmembers' exposure to radiation from
    their flight duties and provide them with information on the effects of
    such radiation

    Appendix II
    Canada and Europe Cabin Occupant Safety
    and Health Responsibilities

    exposure. The European Commission2 is also providing flight crewmembers
    and other mobile workers with free health assessments prior to employment,
    with follow-up health assessments at regular intervals.

    Another European supplement to the ICAO framework is the Joint Aviation
    Authorities (JAA), which represents the civil aviation regulatory
    authorities of a number of European states3 that have agreed to cooperate
    in developing and implementing common safety regulatory standards and
    procedures. JAA uses staff of these authorities to carry out its
    responsibilities for making, standardizing, and harmonizing aviation
    rules, including those for aviation safety, and for consolidating common
    standards among member counties. In addition, JAA is to cooperate with
    other regional organizations or national European state authorities to
    reach at least JAA's safety level and to foster the worldwide
    implementation of harmonized safety standards and requirements through the
    conclusion of international arrangements.

    Membership in JAA is open to members of the European Civil Aviation
    Conference, which currently consists of 41 member countries. Currently, 37
    countries are members or candidate members of JAA. JAA is funded by
    national contributions; income from the sale of publications and training;
    and income from other sources, such as user charges and European Union
    grants. National contributions are based on indexes related to the size of
    each country's aviation industry. The "largest" countries (France,
    Germany, and the United Kingdom) each pay around 16 percent and the
    smallest around 0.6 percent of the total contribution income. For 2003,
    JAA's total budget was about 6.6 million euros.

    In early 1998, JAA launched the Safety Strategy Initiative to develop a
    focused safety agenda to support the "continuous improvement of its
    effective safety system" and further reduce the annual number of accidents
    and fatalities regardless of the growth of air traffic. Two approaches are
    being used to develop the agenda:

    2The European Union, previously known as the European Community, is an
    institutional framework for the construction of a united Europe. The
    European Commission is a governing body that proposes policies and
    legislation.

    3JAA currently has 26 full members and 11 candidate members.

    Appendix II
    Canada and Europe Cabin Occupant Safety
    and Health Responsibilities

    o 	The "historic approach" is based on analyses of past accidents and has
    led to the identification of seven initial focus areas-controlled flight
    into terrain, approach and landing, loss of control, design related,
    weather, occupant safety and survivability, and runway safety.

    o 	The "predictive approach" or "future hazards approach" is based on an
    identification of changes in the aviation system.

    JAA is cooperating in this effort with FAA and other regulatory bodies to
    develop a worldwide safety agenda and avoid duplication of effort. FAA has
    taken the lead in the historic approach, and JAA has taken the lead in the
    future hazards approach.

    JAA officials told us that they use a consensus-based process to develop
    rules for aviation safety, including cabin occupant safety and
    health-related issues. Reaching consensus among member states is time
    consuming, but the officials said the time invested was worthwhile.
    Besides making aviation-related decisions, JAA identifies and resolves
    differences in word meanings and subtleties across languages-an effort
    that is critical to reaching consensus. JAA does not have regulatory
    rule-making authority. Once the member states are in agreement, each
    member state's legislative authority must adopt the new requirements.
    Harmonizing new requirements with U.S. and other international aviation
    authorities further adds to the time required to implement new
    requirements.

    According to JAA officials, they use expert judgment to identify and
    prioritize research and development efforts for aviation safety, including
    airliner cabin occupant safety and health issues, but JAA plans to move
    toward a more data-driven approach.4 While JAA has no funding of its own
    for research and development, it recommends research priorities to its
    member states. However, JAA officials told us that member states' research
    and development efforts are often driven by recent airliner accidents in
    the member states, rather than by JAA's priorities. The planned shift from
    expert judgment to a more data-driven approach will require more
    coordination of aviation research and development across Europe. For
    example, in January 2001, a stakeholder group formed by the European
    Commissioner for Research issued a planning document entitled European

    4According to officials from the United Kingdom's Civil Aviation
    Authority, a JAA member, a limited benefit analysis has been developed to
    provide guidance, but this document has not yet been published.

    Appendix II
    Canada and Europe Cabin Occupant Safety
    and Health Responsibilities

    Aeronautics: A Vision for 2020, which, among other things, characterized
    European aeronautics as a cross-border industry, whose research strategy
    is shaped within national borders, leading to fragmentation rather than
    coherence. The document called for better decision-making and more
    efficient and effective research by the European Union, its member states,
    and aeronautics stakeholders. JAA officials concurred with this
    characterization of European aviation research and development.

    Changes lie ahead for JAA and aviation safety in Europe. The European
    Union recently created a European Aviation Safety Agency, which will
    gradually assume responsibility for rule-making, certification, and
    standardization of the application of rules by the national aviation
    authorities. This organization will eventually absorb all of JAA's
    functions and activities. The full transition from JAA to the safety
    agency will take several years--per the regulation,5 the European Aviation
    Safety Agency must begin operations by September 28, 2003, and transition
    to full operations by March 2007.

    5On July 15, 2002, the European Parliament and the Council of the European
    Union (E.U.) adopted Regulation (EC) No 1592/2002 establishing common
    rules for the E.U. in the field of civil aviation and establishing a new
    European Aviation Safety Agency.

    Appendix III

    Summary of Key Actions FAA Has Taken to Improve Airliner Cabin Safety and
    Health Since 1984

    Key improvement areas Action taken Purpose Status

    Impact

    Stronger (16g) passenger FAA required that seats for newly developed To
    improve the This rule was published on May

    seats aircraft be subjected to more rigorous testing crashworthiness of
    17, 1988, and became effective than was previously required. The tests
    subject airplane seats and June 16, 1988. However, only the seats to the
    forward, downward, and other their ability to prevent newest generation of
    airplanes is directional movements that can occur in an or reduce the
    severity required to have fully tested and accident. Likely injuries under
    various of head, back, and certificated 16g seats. FAA conditions are
    estimated by using instrumented femur injuries. proposed a retrofit rule
    on October crash test dummies. 4, 2002, to phase in 16g seats fleetwide
    within 14 years after adoption of the final rule.

    Overhead FAA issued an airworthiness   To improve the   The airworthiness
         bins           directive requiring                       directive to
                      corrective action for crashworthiness of improve bin
                 overhead bin designs found                    connectors became
                 not to meet the existing    some bins after   effective November
                          rules.                                    20, 1992, and
                                              failures were    applied to Boeing
                                                               737 and 757
                                            observed in a 1989     aircraft.
                                            crash in Kegworth,
                                                 England.

    Fire

    More stringent flammability In 1986, FAA upgraded the fire safety
    standards To give airliner cabin FAA required that all commercial
    standards for interior for cabin interior materials in transport occupants
    more time aircraft produced after August 20, materials airplanes,
    establishing a new test method to to evacuate a burning 1988, have panels
    that exhibit determine the heat release from materials exposed to radiant
    heat and set allowable criteria for heat release rates. airplane by
    limiting heat releases and smoke emissions when cabin interior materials
    are exposed to fire. reduced heat releases and smoke emissions to delay
    the onset of flashover. Although there was no retrofit of the existing
    fleet, FAA is requiring that these improved materials be used whenever the
    cabin is substantially refurbished.

                             In 1984, FAA issued a To retard         This rule
    "Fire-blocking" seat        regulation that burning of        applies to
                                          enhanced                   transport
                            flammability           cabin materials       category
             cushions       requirements for seat        to        aircraft after
                            cushions.                                    November
                                                   increase          26, 1987.
                                                   evacuation
                                                        time.

    Halon fire extinguishers	In March 1985, FAA issued a rule requiring at To
    extinguish in-flight This rule became effective April least two Halon fire
    extinguishers on all fires. 29, 1985, and required commercial airliners,
    in addition to other compliance by April 29, 1986. required extinguishers

    Smoke detectors in In March 1985, FAA issued a rule requiring air To
    identify and This rule became effective on April

    lavatories	carriers to install smoke detectors in lavatories extinguish
    in-flight 29, 1985, and required within 18 months. fires. compliance by
    October 29, 1986.

    Fire extinguishers built in to In March 1985, FAA required air carriers to
    To identify and This rule became effective on April lavatory waste
    receptacles install automatic fire extinguishers in the waste extinguish
    prevent in-29, 1985. paper bins in all aircraft lavatories. flight fires.
    This rule required compliance by April 29, 1987.

                                      Appendix III
                        Summary of Key Actions FAA Has Taken to
                        Improve Airliner Cabin Safety and Health
                                       Since 1984

                             (Continued From Previous Page)

    Key improvement areas Action taken Purpose Status

          Cargo     In 1986, FAA upgraded the   To improve fire         This rule
    compartment  airworthiness               safety                   required
                                                                    compliance on
        protection    standards for ceiling and in the cargo and March 20, 1998.
                          sidewall liner panels
                    used in cargo compartments      baggage
                    of transport
                        category airplanes.      compartment of
                                                    certain
                                                   transport
                                                  aairplanes.

    Cargo compartment fire In 1998, FAA required air carriers to retrofit the
    To improve fire safety This rule became effective March

    detection and suppression	U.S. passenger airliner fleet with fire
    detection in the cargo and 19, 1998, requiring compliance on and
    suppression systems in certain cargo baggage March 20, 2001. compartments.
    This rule applied to over 3,400 compartment of airplanes in service and
    all newly manufactured certain transport

                                           a

    airplanes. airplanes.

    Evacuation

    Access to exits: Type III

      This rule requires improved access to the Type To help ensure that This rule
                                became effective June 3,

    exits III emergency exits (typically smaller, overwing exits) by providing
    an unobstructed passageway to the exit. Transport aircraft with 60 or more
    passenger seats were required to comply with the new standards passengers
    have an unobstructed passageway to exits during an emergency. 1992,
    requiring changes to be made by December 3, 1992. Public address system:
    This rule requires that the public address To eliminate reliance This rule
    became effective

    independent power source	system be independently powered for at least on
    engine or November 27, 1989, for air carrier 10 minutes and that at least
    5 minutes of that auxiliary-power-unit and air taxi airplanes time is
    during announcements. operation for manufactured on or after

    emergency November 27, 1990. announcements.

          Exit row     This rule requires that   To improve      This rule became
           seating     persons seated next to                  effective April 5,
                       emergency exits be                     1990, requiring
                       physically and mentally    passenger   compliance by
                       capable of operating the evacuation in  October 5, 1990.
                       exit and assisting other      an
                       passengers in emergency   emergency.
                             evacuations.
         Location of   Rule issued to limit the                  This rule became
          passenger        distance between      To improve    effective July 24,
    emergency exits adjacent emergency exits               1989, imposing
                             on transport         passenger   requirements on
                        airplanes to 60 feet.   evacuation in airplanes
                                                     an       manufactured after
                                                 emergency.    October 16, 1987.

    Floor proximity emergency Airplane emergency lighting systems must To
    improve This rule became effective escape path marking visually identify
    the emergency escape path passenger November 26, 1984, requiring

    and identify each exit from the escape path. 	evacuation when
    implementation for large transport smoke obscures airplanes by November
    26, 1986. overhead lighting.

    Fire-resistant Emergency evacuation slides  To improve      This technical
         evacuation   manufactured                                standard became
           slides     after December 3, 1984, must              effective for all
                      be fire resistant             passenger   evacuation slides
                      and comply with new radiant  evacuation. manufactured after
                              heat testing                            December 3,
                             procedures. b                           1984.

                               General safety and health

    Preparation for  In 1986, FAA issued a   To improve air   This rule became
          in-flight         rule requiring                       effective August
                         commercial airlines to carriers'       1, 1986,
         emergencies    carry emergency medical preparation     requiring
                                                                compliance as
                                kits.            for in-flight    of that date.
                                                 emergencies.

                                      Appendix III
                        Summary of Key Actions FAA Has Taken to
                        Improve Airliner Cabin Safety and Health
                                       Since 1984

                             (Continued From Previous Page)

    Key improvement areas Action taken Purpose Status

    Ban on smoking for In 1988 and 1989, the Congress passed To limit the
    impact of These laws became effective in majority of domestic legislation
    banning smoking on domestic flights poor cabin air quality 1988, and 1990,
    respectively. commercial flights of varying durations. on occupants'
    health

    Prevention of in-flight In June 1995, following two serious events To
    prevent passenger Information is currently posted on

    injuries	involving turbulence, FAA issued a public injuries from FAA's Web
    site. advisory to airlines urging the use of seat belts turbulence by at
    all times when passengers are seated but increasing public concluded that
    existing rules did not require awareness of the strengthening. importance
    of

    wearing seatbelts. In May 2000, FAA instituted the Turbulence Happens
    public awareness campaign.

    Source: GAO presentation of FAA information.

    aTechnical Class C category cargo compartments are required to have
    built-in extinguishing systems to control fire in lieu of crewmember
    accessibility. Class D category cargo compartments are required to
    completely contain a fire without endangering the safety of the airplane
    occupants.

    bStandard Order (TSO)-C69B (``Emergency Evacuation Slides, Ramps,
    Ramp/Slides, and Slide/Rafts'') prescribes minimum performance standards
    for emergency evacuation slides, ramps, ramp/slides, and slide/rafts,
    including standards for resistance to radiant heat sources.

    Appendix IV

    Summaries of Potential Impact Safety Advancements

    This appendix presents information on the background and status of
    potential advancements in impact safety that we identified, including the
    following:

    o  retrofitting all commercial aircraft with more advanced seats,

    o  improving the ability of airplane floors to hold seats in an accident,

    o  preventing overhead luggage bins from becoming detached or opening,

    o  requiring child safety restraints for children under 40 pounds, and

    o  installing lap belts with self-contained inflatable air bags.1

    Retrofitting All Commercial Aircraft with More Advanced Seats

    Background	In commercial transport airplanes, the ability of a seat to
    protect a passenger from the forces of impact in an accident depends on
    reducing the forces of impact to levels that a person can withstand,
    either by spreading the impact over a larger part of the person's body or
    by decreasing the duration of the impact through the use of
    energy-absorbing seats, an energy-absorbing fuselage and floors, or
    restraints such as seat belts or inflatable seat belt air bags adapted
    from automobile technology. In a 1996 study by R.G.W Cherry & Associates,
    enhancing occupant restraint was ranked as the second most important of 33
    potential ways to improve air crash survivability.2 Boeing officials noted
    that the industry generally

    1Officials with the United Kingdom's Civil Aviation Authority commented
    that inflatable airbags are but one solution for providing upper torso
    restraint. These officials cited a European Union funded "Going Safe"
    seat, which through an energy-absorbing device enables a lap and diagonal
    belt system to be fitted to an unmodified seat rail.

    2R.G.W. Cherry & Associates, Analysis of Structural Factors Influencing
    the Survivability of Occupants in Aeroplane Accidents, Civil Aviation
    Authority, Paper 96011 (London: December 1996).

    Appendix IV
    Summaries of Potential Impact Safety
    Advancements

    agrees with this view but that FAA and the industry are at odds over the
    means of implementing these changes.

    According to an aviation safety expert, seats and restraints should be
    considered as a system that involves

    o  the seats themselves,

    o  seat restraints such as seat belts,

    o  seat connections to the floor,

    o  the spacing between seats, and

    o  furnishings in the cabin area that occupants could strike in an
    accident.

    To protect the occupant, a seat must not only absorb energy well but also
    stay attached to the floor of the aircraft. In other words, the "tie-down"
    chain must remain intact. Although aircraft seat systems are designed to
    withstand about 9 to 16 times the force of gravity, the limits of human
    tolerance to impact substantially exceed the aircraft and seat design
    limits. A number of seat and restraint devices have been shown in testing
    to improve survivability in aviation accidents. Several options are to
    retrofit the entire current fleet with fully tested 16g seats, use
    rearward-facing seats, require three-point auto-style seat belts with
    shoulder harnesses, and install auto-style air bags.

    FAA regulations require seats for newly certified airplane designs to pass
    more extensive tests than were previously required to protect occupants
    from impact forces of up to 16 times the force of normal gravity in the
    forward direction; seat certification standards include specific
    requirements to protect against head, spine, and leg injuries (see fig.
    5).3 FAA first required 16g seats and tests for newly designed,
    certificated

    3The 1988 seat dynamic performance standards changed seat standards and
    testing. The new standards expanded seat testing to include potential
    injuries caused by head strikes on the back of seats and on stationary
    bulkheads, as well as criteria limiting lumbar and femur loads. These
    limits, if exceeded, could cause injuries that could prevent evacuation.
    Seats must be tested for forces in several directions to account for
    forward, downward, and other directional movements such as may occur in an
    accident. Previous FAA regulations required seats to be tested in only one
    primary direction at 9gs of force. The 16g level was adopted rather than a
    higher standard because the floor tracks of many of the airplanes in use
    in 1988 would break away upon an impact of more than 16gs.

    Appendix IV
    Summaries of Potential Impact Safety
    Advancements

    airplanes in 1988; new versions of existing designs were not required to
    carry 16g seats.4 Since 1988, however, in anticipation of a fleetwide
    retrofit rule, manufacturers have increasingly equipped new airplanes with
    "16g-compatible" seats that have some of the characteristics of fully
    certified 16g seats.5 Certifying a narrow-body airplane type to full 16g
    seat certification standards can cost $250,000.6,7

    Figure 5: Coach Seating and Impact Position in Coach Seating

    4The initial proposed rule, Retrofit of Improved Seats in Air Carrier
    Transport-Category Airplanes, 53 Fed. Reg. 17650 (1988) proposed requiring
    compliance with improved crashworthiness standards for all seats of
    transport-category airplanes used under part 121 and part 135 and
    prohibiting the operation of these airplanes unless all seats met the
    crashworthiness performance standards required by Improved Seat Safety
    Standards, 53 Fed. Reg. 17640 (1988).

    5In general, most 16g-compatible seats meet the structural requirements of
    the 16g seat rule but do not need to meet the head injury criteria.

    6Each aircraft type typically has 8 to 10 different types of seats, each
    of which must be certified; a typical economy class seat costs about
    $1,800. For marketing reasons, airlines usually choose their own
    distinctive seats, which must be certified for each type of airplane they
    fly.

    7According to a Boeing Official, one cost estimate compiled by ATA and the
    Aerospace Industries Association in response to NPRM 88-8 presented in
    December 1988 showed the recurring per program cost [was listed] at
    $440,000.

                                      Appendix IV
                          Summaries of Potential Impact Safety
                                      Advancements

    In 1998 FAA estimated that 16g seats would avoid between about 210 to 410
    fatalities and 220 to 240 serious injuries over the 20-year period from
    1999 through 2018. A 2000 study funded by FAA and the British Civil
    Aviation Authority estimated that if 16g seats had been installed in all
    airplanes that crashed from 1984 through 1998, between 23 to 51 fewer U.S.
    fatalities and 18 to 54 fewer U.S. serious injuries would have occurred
    over the period. A number of accidents analyzed in that study showed no
    benefit from 16g seats because it was assumed that 16g seats would have
    detached from the floor, offering no additional benefits compared with
    older seats.8 Worldwide, the study estimated, about 333 fewer fatalities
    and 354 fewer serious injuries would have occurred during the period had
    the improved seats been installed. Moreover, if fire risks had been
    reduced, the estimated benefits of 16g seats might have increased
    dramatically, as more occupants who were assumed to survive the impact but
    die in the ensuing fire would then have survived both the impact and
    fire.9

    Status	Seats that meet the 16g certification requirements are currently
    available and have been required on newly certificated aircraft designs
    since 1988. However, newly manufactured airplanes of older certification,
    such as Boeing 737s, 757s, or 767s, were not required to be equipped with
    16g certified seats. Recently, FAA has negotiated with manufacturers to
    install full 16g seats on new versions of older designs, such as all newly
    produced 737s.10 In October 2002, FAA published a new proposal to create a
    timetable for all airplanes to carry fully certified 16g seats within 14
    years.11 The comment period for the currently proposed rule ended in March
    2003.

    8R.G.W. Cherry & Associates, Benefit Analysis for Aircraft 16-g Dynamic
    Seats, DOT/FAA/AR-00/13 (Washington, D.C.: April 2000). This study
    examined 25 large commercial airplane accidents that occurred from 1984
    and through 1998 and possibly involved seat-related fatalities or
    injuries.

    9In commenting on the proposed 16g seat retrofit rule, Boeing noted that
    there were fundamental, fatal flaws in both the analysis of benefits and
    the analysis of costs of implementing this rule.

    10Until recently, FAA generally did not require a manufacturer to meet
    new, higher safety standards that are put in place after the date the
    manufacturer applies for a type certificate unless FAA can demonstrate
    that an unsafe condition exists. FAA's changed product rule requires
    manufacturers to comply with the latest airworthiness standards when
    significant design changes are proposed for a derivative aircraft that
    will be certificated under an amended or supplemental type certificate. 65
    Fed. Reg. 36244 (2002).

    11Improved Seats in Air Carrier Transport Category Airplanes, 67 Fed. Reg.
    62294 (2002).

    Appendix IV
    Summaries of Potential Impact Safety
    Advancements

    Under this proposal, airframe manufacturers would have 4 years to begin
    installing 16g seats in newly manufactured aircraft only, and all
    airplanes would have to be equipped with full 16g seats within 14 years or
    when scheduled for normal seat replacement. FAA estimated that upgrading
    passenger and flight attendant seats to meet full 16g requirements would
    avert approximately 114 fatalities and 133 serious injuries over 20 years
    following the effective date of the rule. This includes 36 deaths that
    would be prevented by improvements to flight attendant seats that would
    permit attendants to survive the impact and to assist more passengers in
    an evacuation.

    FAA estimated the costs to avert 114 fatalities and 133 serious injuries
    at $245 million in present-value terms, or $519 million in overall costs,
    which, according to FAA's analysis, would approximate the monetary
    benefits from the seats.12 FAA estimated that about 7.5 percent of
    airplane seats would have to be replaced before they would ordinarily be
    scheduled for replacement. FAA's October 2002 proposal divides seats into
    three classes according to their approximate performance level. Although
    FAA does not know how many seats of each type seat are in service, it
    estimates that about 44 percent of commercial-service aircraft are
    equipped with full 16g seats, 55 percent have 16g-compatible seats, and
    about 1 percent have 9g seats. The 16g-compatible or partial 16g seats
    span a wide range of capabilities; some are nearly identical to full 16g
    seats but have been labeled as 16g-compatible to avoid more costly
    certification, and other partial 16g seats offer only minor improvements
    over the older generation of 9g seats. To determine whether these seats
    have the same performance characteristics as full 16g seats, it may be
    sufficient, in some cases, to review the company's certification
    paperwork; in other cases, however, full crash testing of actual 16g seats
    may be necessary to determine the level of protection provided.

    FAA is currently considering the comments it received on its October 2002
    proposal. Industry comments raised concerns about general costs, the costs
    of retrofitting flight attendant seats, and the possibility that older
    airplanes designed for 9g seats might require structural changes to
    accommodate full 16g seats. One comment expressed the desire to give some
    credit for and "grandfather" in at least some partial 16g seats.

    12FAA assumed benefits of $3 million for an averted fatality and $0.5
    million for an averted serious injury.

                                      Appendix IV
                          Summaries of Potential Impact Safety
                                      Advancements

    Improving the Ability of Airplane Floors to Hold Seats in an Accident

    Background	In an accident, a passenger's chances of survival depend on how
    well the passenger cabin maintains "living space" and the passenger is
    "tied down" within that space. Many experts and reports have noted floor
    retention- the ability of the aircraft cabin floor to remain intact and
    hold the passenger's seat and restraint system during a crash-as critical
    to increasing the passenger's chances of survival. Floor design concepts
    developed during the late 1940s and 1950s form the basis for the cabin
    floors found in today's modern airplanes.

    Accident investigations have documented failures of the floor system in
    crashes.13 New 16g seat requirements were developed in the 1980s. 16g
    seats were intended to be retrofitted on aircraft with traditional 9g
    floors and were designed to maximize the capabilities of existing floor
    strength. While 16g seats might be strong, they could also be inflexible
    and thus fail if the floor deformed in a crash. Under the current 16g
    requirement, the seats must remain attached to a deformed seat track and
    floor structure representative of that used in the airplane.14 To meet
    these requirements, the seat was expected to permanently deform to absorb
    and limit impact forces even if the 16g test conditions were exceeded
    during a crash.

    A major accident related to floor deformation occurred at Kegworth,
    England, in 1989. A Boeing 737-400 airplane flew into an embankment on
    approach to landing. In total, only 21 of the 52 triple seats-all
    "16g-compatible" -remained fully attached to the cabin floor; 14 of those
    that remained attached were in the area where the wing passes through the

    13A study of survivable accidents that took place from 1970 through 1978
    indicated that floor deformation during a crash was a primary cause of
    seat failure in 60 percent of the accidents. (Chandler, et al.,
    DOT/FAA/CT-82-118)

    14In the dynamic 16g seat test with a deformed floor, one floor track must
    be pitched 10 degrees (up or down) relative to the other floor track,
    which must in turn be rolled 10 degrees.

                                      Appendix IV
                          Summaries of Potential Impact Safety
                                      Advancements

    cabin and the area is stronger than other areas to support the wing.15 In
    this section of the airplane, the occupants generally survived, even
    though they were exposed to an estimated peak level of 26gs. The front
    part of the airplane was destroyed, including the floor; most of these
    seats separated from the airplane, killing or seriously injuring the
    occupants. An FAA expert noted that the impact was too severe for the
    airplane to maintain its structural integrity and that 16g seats were not
    designed for an accident of that severity. The British Air Accidents
    Investigation Branch noted that fewer injuries occurred in the accident
    than would probably have been the case with earlier-generation seats.
    However, the Branch also noted that "relatively minor engineering changes
    could significantly improve the resilience and toughness of cabin floors .
    . . and take fuller advantage of the improved passenger seats." The Branch
    reported that where failures occurred, it was generally the seat track
    along the floor that failed, and not the seat, and that the rear
    attachments generally remained engaged with the floor, "at least partially
    due to the articulated joint built into the rear attachment, an innovation
    largely stemming from the FAA dynamic test requirements." The Branch
    concluded that "seats designed to these dynamic requirements will
    certainly increase survivability" but "do not necessarily represent an
    optimum for the long term . . . if matched with cabin floors of improved
    strength and toughness."16

    Status	Several reports have recommended structural improvements to floors.
    A case study of 11 major accidents for which detailed information was
    available found floor issues to be a major cause of injury or fatalities
    in 4 accidents and a minor cause in 1 accident. Another study estimated
    the past benefits of 16g seats in U.S. accidents between 1984 and 1998 and
    found no hypothetical benefit from 16g seats in a number of accidents
    because the floor was extensively disrupted during impact.17 In other

    15Some 16g-compatible seats were manufactured to meet 16g dynamic testing
    standards but did not complete FAA's certification process for floor
    deformation on representative floors and seat tracks and technically met
    only the 9g seat certification requirements.

    16Report on the accident to Boeing 737-400 G-OBME near Kegworth,
    Leicestershire, on 8 January 1989, Aircraft Accident Report 4/90, AAIB,
    DOT, London, HMSO; "Recommendations for Injury Prevention in Transport
    Aviation Accidents," prepared for NASA, Langley Research Center, by Simula
    Technologies, Inc., February 2, 2000, TR-99112, S97324.

    17 "Benefit Analysis for Aircraft 16-g Dynamic Seats," Final Report, U.S.
    Department of Transportation (DOT/FAA/AR-00/13) and U.K Civil Aviation
    Authority (CAA Paper 99003).

                                      Appendix IV
                          Summaries of Potential Impact Safety
                                      Advancements

    words, unless the accidents had been less severe or the floor and seat
    tracks had been improved beyond the 9g standard on both new and old jets,
    newer 16g seats would not have offered additional benefits compared with
    the older seats that were actually on the airplane during the accidents
    under study.

    A research program on seat and floor strength was recently conducted by
    the French civil aviation authority, the Direction Generale de l'Aviation
    Civile. Initial findings of the research program on seat-floor attachments
    have not shown dramatic results and showed no rupture or plastic
    deformation of any cabin floor parts during a 16g test. However, French
    officials noted that they plan to perform additional tests with more rigid
    seats. Because many factors are involved it is difficult to identify the
    interrelated issues and interactions between seats and floors. A possible
    area for future research, according to French officials, is to examine
    dynamic floor warping during a crash to improve impact performance.

    FAA officials said they have no plans to change floor strength
    requirements. FAA regulations require floors to meet impact forces likely
    to occur in "emergency landing conditions," or generally about 9gs of
    longitudinal static force. According to several experts, stronger floors
    could improve the performance of 16g seats. In addition, further
    improvement in seats beyond the 16g standard would likely require improved
    floors.

    Preventing Overhead Storage Bin Detachment to Protect Passengers in an
    Accident

    Background	In an airplane crash, overhead luggage bins in the cabin
    sometimes detach from their mountings along the ceiling and sidewalls and
    can fall completely or allow pieces of luggage to fall on passengers'
    heads (See fig. 6.). While only a few cases have been reported in which
    the impact from dislodged overhead bins was the direct cause of a crash
    fatality or injury, a study for the British Civil Aviation Authority that
    attempted to identify the

    Appendix IV
    Summaries of Potential Impact Safety
    Advancements

    specific characteristics of each fatality in 42 fatal accidents estimated
    that the integrity of overhead bin stowage was the 17th most important of
    32 factors used to predict passenger survivability.18 Maintaining the
    integrity of bins may also help speed evacuation after a crash.

    Safer bins have been designed since bin problems were observed in a Boeing
    737 accident in Kegworth, England, in 1989, when nearly all the bins
    failed and fell on passengers. FAA tested bins in response to that
    accident. The Kegworth bins were certified to the current FAA 9g
    longitudinal static loading standards, among others. When FAA subsequently
    conducted longitudinal dynamic loading tests on the types of Boeing bins
    involved, the bins failed. Several FAA experts said that the overhead bins
    on 737s had a design flaw. FAA then issued an airworthiness directive that
    called for modifying all bins on Boeing 737 and 757 aircraft. The
    connectors for the bins were strengthened in accordance with the
    airworthiness directive, and the new bins passed FAA's tests.

    The British Air Accidents Investigation Branch recommended in 1990 that
    the performance of both bins and latches be tested more rigorously,
    including the performance of bins "when subjected to dynamic crash pulses
    substantially beyond the static load factors currently required." NTSB has
    made similar recommendations.

    Turbulence reportedly injures at least 15 U.S. cabin occupants a year, and
    possibly over 100. Most of these injuries are to flight attendants who are
    unrestrained. Some injuries are caused by luggage falling from bins that
    open in severe turbulence. Estimates of total U.S. airline injuries from
    bin-related falling luggage range from 1,200 to 4,500 annually, most of
    which occur during cruising rather than during boarding or disembarking.19

    The study for the British Civil Aviation Authority noted above found that
    as many as 70 percent of impact-related accidents involve overhead bins
    that become detached. However, according to the report, bin detachment
    does not appear to be a major factor in occupants' survival and data are
    insufficient to support a specific determination about the mechanism of

    18R.G.W. Cherry & Associates, Analysis of Structural Factors Influencing
    the Survivability of Occupants in Aeroplane Accidents, Civil Aviation
    Authority, Paper 96011 (London: December 1996).

    19Flight Safety Foundation, "Increased Amount and Types of Carry-On
    Baggage Bring New Industry Responses," November-December 1997, Vol. 32,
    No. 6, p. 6.

                                      Appendix IV
                          Summaries of Potential Impact Safety
                                      Advancements

    failure. FAA has conducted several longitudinal and drop tests since the
    Kegworth accident, including drops of airplane fuselage sections with
    overhead storage bins installed. A 1993 dynamic vertical drop test showed
    some varying bin performance problems at about 36gs of downward force. An
    FAA longitudinal test in 1999 tested two types of bins at 6g, at the 9g
    FAA certification requirement, and at the 16g level; in the 16g
    longitudinal test, one of the two bins broke free from its support
    mountings.

    Status	In addition to the requirement that they withstand forward
    (longitudinal) loads of slightly more than 9gs, luggage bins must meet
    other directional loading requirements.20 Bin standards are part of the
    general certification requirements for all onboard objects of mass. FAA
    officials said that overhead bins no longer present a problem, appear to
    function as designed, and meet standards. An FAA official told us that
    problems such as those identified at Kegworth have not appeared in later
    crashes. Another FAA official said that while Boeing has had some record
    of bin problems, the problems are occasional and quickly rectified through
    design changes. Boeing officials told us that the evidence that bins
    currently have latch problems is anecdotal.

    Suggestions for making bins safer in an accident include adding features
    to absorb impact forces and keep bins attached and closed during
    structural deformation; using dynamic 16g longitudinal impact testing
    standards similar to those for seats; and storing baggage in alternative
    compartments in the main cabin, elsewhere in the aircraft, or under seats
    raised for that purpose.

                                   Child Safety Seats

    Background	Using a correctly-designed child safety seat that is strapped
    in an airplane seat offers protection to a child in an accident or
    turbulence (see fig. 6). By contrast, according to many experts, holding a
    child under two years old on an adult's lap, which is permitted, is unsafe
    for both the child and for other

    20Bins are required to withstand 9g forward (longitudinal), 3g upward, 6g
    downward, and other load requirements.

    Appendix IV
    Summaries of Potential Impact Safety
    Advancements

    occupants who could be struck by the child in an accident. Requiring child
    safety seats for infants and small children on airplanes is one of NTSB's
    "most wanted" transportation safety improvements. The British Air
    Accidents Investigation Branch made similar recommendations, as did a 1997
    White House Commission report on aviation.

                        Figure 6: Examples of Child Safety Seats

    Appendix IV
    Summaries of Potential Impact Safety
    Advancements

    An FAA analysis of survivable accidents from 1978 through 1994 found that
    9 deaths, 4 major injuries, and 8 minor injuries to children occurred. The
    analysis also found that the use of child safety seats would have
    prevented 5 deaths, all the major injuries, and 4 to 6 of the minor
    injuries. Child safety advocates have pointed to several survivable
    accidents in which children died-a 1994 Charlotte, North Carolina, crash;
    a 1990 Cove Neck, New York, accident; and a 1987 Denver, Colorado,
    accident-as evidence of the need for regulation.

    A 1992 FAA rule required airlines to allow child restraint systems, but
    FAA has opposed mandatory child safety seats on the basis of studies
    showing that requiring adults to pay for children's seats would induce
    more car travel, which the study said was more dangerous for children than
    airplane travel. One study published in 1995 by DOT estimated that if
    families were charged full fares for children's seats, 20 percent would
    choose other modes of transportation, resulting in a net increase of 82
    deaths among children and adults over 10 years.

    If child safety seats are required, airlines may require adults wishing to
    use child safety seats to purchase an extra seat for the child's safety
    seat. FAA officials told us that they could not require that the seat next
    to a parent be kept open for a nonpaying child. However, NTSB has
    testified that the scenarios for passengers taking other modes of
    transportation are flawed because FAA assumed that airlines would charge
    full fares for infants currently traveling free. NTSB noted in 1996 that
    airlines would offer various discounts and free seats for infants in order
    to retain $6 billion in revenue that would otherwise be lost to auto
    travel. Airlines have already responded to parents who choose to use child
    restraint systems with scheduling flexibility, and many major airlines
    offer a 50 percent discount off any fare for a child under 2 to travel in
    an approved child safety seat. The 1995 DOT study, however, estimated that
    even if a child's seat on an airplane were discounted 75 percent, some
    families would still choose car travel and that the choice by those
    families to drive instead of fly would result in a net increase of 17
    child and adult deaths over 10 years.

    In FAA tests, some but not all commercially available automobile child
    restraint systems have provided adequate protection in tests simulating
    airplane accidents. Prices range from less than $100 for a child safety
    seat marketed for use in both automobiles and airplanes to as much as
    $1,300 for a child safety seat developed specifically for use in
    airplanes.

                                      Appendix IV
                          Summaries of Potential Impact Safety
                                      Advancements

    A drawback to having parents, rather than airlines, provide child safety
    seats for air travel is that some models may be more difficult to fit into
    airplane seat belts, making a proper fit more challenging. While the
    performance of standardized airline-provided seats may be better than that
    of varied FAA-certified auto-airplane seats, one airline said that
    providing seats could present logistical problems for them. However,
    Virgin Atlantic Airlines supplies its own specially developed seats and
    prohibits parents from using their own child seats. Because turbulence can
    be a more frequent danger to unrestrained children than accidents, one
    expert told us that a compromise solution might include allowing some type
    of alternative in-flight restraint.

    Status	Child safety seats are currently available for use on aircraft. The
    technical issues involved in designing and manufacturing safe seats for
    children to use in both cars and airplanes have largely been solved,
    according to FAA policy officials and FAA researchers. Federal regulations
    establish requirements for child safety seats designed for use in both
    highway vehicles and aircraft by children weighing up to 50 pounds. FAA
    officials explained that regulations requiring child safety seats have
    been delayed, in part, because of public policy concerns that parents
    would drive rather than fly if they were required to buy seats for their
    children. On February 18, 1998, FAA asked for comments on an advanced
    notice of proposed rule-making to require the use of child safety seats
    for children under the age of

    2. FAA sponsored a conference in December 1999 to examine child restraint
    systems. At that conference, the FAA Administrator said the agency would
    mandate child safety seats in aircraft and provide children with the same
    level of safety as adults. FAA officials told us that they are still
    considering requiring the use of child safety seats but have not made a
    final decision to do so. If FAA does decide to provide "one level of
    safety" for adults and children, as NTSB advocates, parents may opt to
    drive to their destinations to avoid higher travel costs, thereby
    statistically exposing themselves and their children to more danger. In
    addition, FAA will have to decide whether the parents or airlines will
    provide the seats.

    If FAA decides to require child safety seats, it will need to harmonize
    its requirements with those of other countries where requirements differ,
    as the regulations on child restraint systems vary. In Canada, as in the
    United States, child safety seats are not mandatory on registered
    aircraft. In Europe, the regulations vary from country to country, but no
    country requires their use. Australia's policy permits belly belts but
    discourages their use. An Australian official said in 1999 that Australia
    was waiting for

                                      Appendix IV
                          Summaries of Potential Impact Safety
                                      Advancements

    the United States to develop a policy in this area and would probably
    follow that policy.

    Inflatable Lap Belt Air Bags

    Background	Lap belts with inflatable air bags are designed to reduce the
    injuries or death that may result when a passenger's head strikes the
    airplane interior. These inflatable seat belts adapt advanced automobile
    air bag technology to airplane seats in the form of seat belts with
    embedded air bags. If a passenger loses consciousness because of a head
    injury in an accident, even a minor, nonfatal concussion can cause death
    if the airplane is burning and the passenger cannot evacuate quickly.
    Slowing the duration of the impact with an air bag lessens its lethality.
    According to a manufacturer's tests using airplane seats on crash sleds,
    lap belts with air bags can likely reduce some impact injuries to
    survivable levels.21

    FAA does not require seats to be tested in sled tests for head impact
    protection when there would be "no impact" with another seat row or
    bulkhead wall, such as when spacing is increased to 42 inches from the
    more typical 35 inches. While more closely spaced economy class seat rows
    can provide head impact protection through energy-absorbing seat backs,
    seats in no impact positions have tested poorly in head injury
    experiments, resulting in severe head strikes against the occupants' legs
    or the floor, according to the manufacturer. This no impact exemption from
    FAA's head injury criteria can include exit rows, business class seats,
    and seats behind bulkhead walls and could permit as many as 30 percent of
    seats in some airplanes to be exempt from the head impact safety criteria
    that row-to-row seats must meet.

    Status	According to the manufacturer, 13 airlines have installed about
    1,000 of the devices in commercial airliners, mainly at bulkhead seats;
    about 200 of

    21One manufacturer's testing shows that the inflatable lap belts can
    reduce head injury criteria scores from about 2,000 to 200-300 in a 16g
    impact. A score of 1,000 implies a skull fracture, possible loss of
    consciousness, and a 16 percent risk of life-threatening brain injury.

    Appendix IV
    Summaries of Potential Impact Safety
    Advancements

    these are installed in the U.S. fleet. All of the orders and installations
    so far have been done to meet FAA's seat safety regulations rather than
    for marketing reasons, according to the manufacturer.

    The airlines would appear to benefit from using the devices in bulkhead
    seats if that would allow them to install additional rows of seats. While
    the amount of additional revenue would depend on the airplane design and
    class of seating, two additional seats may produce more net revenue per
    year than the cost for the devices to be installed throughout an
    aircraft.22 Economic constraints are acquisition costs, maintenance costs,
    and increased fuel costs due to weight. The units currently weigh about 3
    pounds per seat, or 2 pounds more than current seat belts. According to
    the manufacturer, the air bag lap belts currently cost $950 to $1,100,
    including maintenance. The manufacturer estimated that if 5 percent of all
    U.S. seat positions were equipped with the devices (about 50,000 seats per
    year), the cost would drop to about $300 to $600 per seat, including
    installation.23

    Lap belt air bags have been commercially available for only a few years.
    FAA's Civil Aerospace Medical Institute assisted the developers of the
    devices; manufacturers for both passenger and military use (primarily
    helicopter) are conducting ongoing research. FAA and other regulatory
    bodies have no plans to require their installation, but airlines are
    allowed to use them. The extent to which these devices are installed will
    depend on each airline's analysis of the cost and benefits.

    22At an annual life-cycle cost of approximately $12,000 to outfit an
    average airliner with lap belt air bags on all seats of the U.S. fleet,
    assuming an installation cost of $450 per seat position not including
    maintenance and replacement costs. A GAO analysis of the 2002 Annual
    Report of Southwest Airlines, which has relatively low passenger revenue
    per available seat mile compared with other airlines, found that each seat
    produced an annual net revenue of about $10,000. See appendix VIII for our
    analysis of the costs associated with lap belts.

    23According to the manufacturer, the installation of the most common
    design requires maintenance of one minute per seat position for a
    diagnostic test every 1,900 flight hours, and the devices must be
    refurbished about once every 7 years at about a third of the initial
    price.

    Appendix V

    Summaries of Potential Fire Safety Advancements

    This appendix presents information on the background and status of
    potential advancements in fire safety that we identified, including the
    following:

    o  preventing fuel tank explosions with fuel tank inerting;

    o  preventing in-flight fires with arc fault circuit breakers;

    o  identifying in-flight fires with multisensor fire and smoke detectors;

    o 	suppressing in-flight and postcrash fires by using water mist fire
    suppression systems;

    o  mitigating postcrash damage and injury by using less flammable fuels;

    o 	mitigating in-flight and postcrash fires by using fire-resistant
    thermal acoustic insulation;

    o 	mitigating fire-related deaths and injuries by using
    ultra-fire-resistant polymers; and

    o 	mitigating fire deaths and injuries with sufficient airport rescue and
    fire fighting.

                                   Fuel Tank Inerting

    Background	Fuel tank inerting involves pumping nitrogen-enriched air into
    an airliner's fuel tanks to reduce the concentration of oxygen to a level
    that will not support combustion. Nitrogen gas makes a fuel tank safer by
    serving as a fire suppressant. The process can be performed with both
    ground-based and onboard systems, and it significantly reduces the
    flammability of the center wing tanks, thereby lowering the likelihood of
    a fuel tank explosion.

    Following the crash of TWA Flight 800 in 1996, in which 230 people died,
    NTSB determined that the probable cause of the accident was an explosion
    in the center wing fuel tank. The explosion resulted from the ignition of
    flammable fuel vapors in this tank, which is located in the fuselage in
    the space between the wing junctions. NTSB subsequently placed the
    improvement of fuel tank design on its list of "Most Wanted Safety

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    Improvements" and recommended that fuel tank inerting be considered an
    option to eliminate the likelihood of fuel tank explosions.

    FAA issued Special Federal Aviation Regulation 881 to eliminate or
    minimize the likelihood of ignition sources by revisiting the fuel tank's
    design. Issued in 2001, the regulation consists of a series of FAA
    regulatory actions aimed at preventing the failure of fuel pumps and pump
    motors, fuel gauges, and electrical power wires inside these fuel tanks.
    In late 2002, FAA amended the regulation to allow for an "equivalent level
    of safety" and the use of inerting as part of an alternate means of
    compliance.

    In a 2001 report, an Aviation Rule-making Advisory Committee tasked with
    evaluating the benefits of inerting the center wing fuel tank estimated
    these benefits in terms of lives saved. After projecting possible
    in-flight and ground fuel tank explosions and postcrash fires from 2005
    through 2020, the committee estimated that 132 lives might be saved from a
    ground-based system and 253 lives might be saved from an onboard system.2

    Status	Neither of the two major types of fuel tank inerting-ground-based
    and onboard-is currently available for use on commercial airliners because
    additional development is needed.3 Both types offer benefits and
    drawbacks.

    o 	A ground-based system sends a small amount of nitrogen into the center
    wing tank before departure. Its benefits include that (1) it requires no
    new technology development for installation, (2) the tank can be inerted
    in 20 minutes, and (3) it carries a lesser weight penalty. Its drawbacks
    include that it is unable to inert for descent, landing, and taxiing to
    the

    1ATA noted that more than 80 fuel tank Airworthiness Directives have been
    adopted since the crash of TWA Flight 800 and that a similar number of
    directives are currently under development.

    2The committee also estimated, on the basis of data on nitrogen exposure
    from the Occupational Safety and Health Administration and the National
    Institute of Occupational Safety and Health, that from 24 to 81 lives
    could be lost over the same period, depending on the degree of oxygen
    depletion. The report did not specifically indicate whether this forecast
    was for a ground-based, onboard, hybrid, or any other inerting system.

    3By using more general terminology, this terminology excludes hybrid and
    liquid nitrogen inerting systems, also considered by the Aviation
    Rule-making Advisory Committees for their 1998 and 2001 reports.

    Appendix V
    Summaries of Potential Fire Safety
    Advancements

    destination gate, and nitrogen supply systems are needed at each terminal
    gate and remote parking area at every airport.

    o 	An onboard system generates nitrogen by transferring some of the engine
    bleed air - air extracted from the jet engines to supply the cabin
    pressurization system in normal flight-through a module that separates air
    into oxygen and nitrogen and discharges the nitrogen enriched air into the
    fuel tank. Its benefits include that (1) it is self-reliant and (2) it
    significantly reduces an airplane's vulnerability to lightning, static
    electricity, and incendiary projectiles throughout the flight's duration.4
    Its drawbacks include that it (1) weighs more, (2) increases the
    aircraft's operating costs, and (3) may decrease the aircraft's
    reliability.5

    According to FAA, its fire safety experts' efforts to develop a
    lighter-weight system for center wing tank inerting have significantly
    increased the industry's involvement. Boeing and Airbus are working on
    programs to test inerting systems in flight. For example, Boeing has
    recently completed a flight test program with a prototype system on a 747.

    None of the U.S. commercial fleet is equipped with either ground-based or
    onboard inerting systems, though onboard systems are in use in U.S. and
    European military aircraft. Companies working in this field are focused on
    developing new inerting technologies or modifying existing ones. A
    European consortium is developing a system that combines onboard center
    wing fuel tank inerting with sensors and a water-mist-plus-nitrogen fire
    suppression system for commercial airplanes.

    In late 2002, FAA researchers successfully ground-tested a prototype
    onboard inerting system using current technology on a Boeing 747SP. New
    research also enabled the agency to ease a design requirement, making the
    inerting technology more cost-effective. This new research showed that

    4According to an FAA safety expert, FAA is addressing only the center wing
    tank because of its significantly higher flammability exposure and the low
    risk of an explosion in the wing tanks.

    5A current controversial issue is whether inerting technology will be
    considered flight-critical hardware-and therefore will be required to
    function properly for the aircraft to fly. If it is deemed flight
    critical, its reliability may affect the dispatch rate of the aircraft.
    For example, if the technology experiences operational problems, the
    aircraft may be allowed to fly only 25 times a week, even if it is
    scheduled to fly 30 times a week. This problem reduces revenue to the
    airline and is a greater concern for civilian than for military aviation,
    because there are usually replacements for military aircraft.

    Appendix V
    Summaries of Potential Fire Safety
    Advancements

    reducing the oxygen level in the fuel tank to 12 percent-rather than 9
    percent, as was previously thought-is sufficient to prevent fuel tank
    explosions in civilian aircraft.6 FAA also developed a system that did not
    need the compressors that some had considered necessary. Together, these
    findings allowed for reductions in the size and power demands of the
    system.

    FAA plans to focus further development on the more practical and
    cost-effective onboard fuel tank inerting systems. For example, to further
    improve their cost-effectiveness, the systems could be designed both to
    suppress in-flight cargo fires, thereby allowing them to replace Halon
    extinguishing agents, and to generate oxygen for emergency
    depressurizations, thereby allowing them to replace stored oxygen or
    chemical oxygen generators.

    NASA is also conducting longer-term research on advanced technology
    onboard inert gas-generating systems and onboard oxygen-generating
    systems. Its research is intended (1) to develop the technology to improve
    its efficiency, weight, and reliability and (2) to make the technology
    practical for commercial air transport. NASA will fund the development of
    emerging technologies for ground-based technology demonstration in fiscal
    year 2004. NASA is also considering the extension of civilian transport
    inerting technology to all fuel tanks to help protect airplanes against
    terrorist acts during approaches and departures.

    The cost of the system, its corresponding weight, and its unknown
    reliability are the most significant factors affecting the potential use
    of center wing fuel tank inerting. New cost and weight estimates are
    anticipated in 2003.

    6FAA fuel tank safety experts conducted tests under high temperatures and
    found that a tank with an oxygen level of 12 percent was inert against
    internal threats, such as sparks and hot surfaces. According to one FAA
    expert, the system provides a "below 12 percent" inert tank under all
    conditions except for a brief time during descent when local pockets in
    the tank may approach 16 percent oxygen. The expert said that at this
    time, the tank is generally cool enough to be nonflammable even with
    normal air (21 percent oxygen) in the tank. If the tank is cool enough,
    internal threats will not ignite the fuel air mixture. He said the
    probability of explosions is very low in the wing tanks because they are
    not heated by other airplane systems.

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    o 	In 2001, FAA estimated total costs to equip the worldwide fleet at $9.9
    billion for ground-based, and $20.8 billion for onboard, inerting
    systems.7

    o 	In 2002, FAA officials developed an onboard system for B-747
    flight-testing. The estimated cost was $460,000. The officials estimated
    that each system after that would cost about $200,000. The weight of the
    FAA prototype system is 160 pounds.8 A year earlier, NASA estimated the
    weight for a B-777 system with technology in use in military aircraft at
    about 550 pounds.9

    Arc Fault Circuit Breaker

    Background	Arcing faults in wiring may provide an ignition source that can
    start fires. Electrical wiring that is sufficiently damaged might cause
    arcing or direct shorting resulting in smoking, overheating, or ignition
    of neighboring materials. A review of data produced by FAA, the Airline
    Pilots Association, and Boeing showed that electrical systems have been a
    factor in approximately 50 percent of all aircraft occurrences involving
    smoke or fire and that wiring has been implicated in about 10 percent of
    those occurrences. In addition, faulty or malfunctioning wiring has been a
    factor in at least 15 accidents or incidents investigated by NTSB since
    1983. Properly selecting, routing, clamping, tying, replacing, marking,
    separating, and cleaning around wiring areas and proper maintenance all
    help mitigate the potential for wire system failures, such as arcing, that
    could lead to smoke, fire and loss of function. Chemical degradation, age
    induced cracking, and damage due to maintenance may all create a scenario
    which

    7These estimates included the costs for modifying aircraft that are
    currently in service, in production, and being designed, and they assumed
    a predicted reduction in the accident rate of 75 percent.

    8This system does not have the capability to inert the cargo compartment,
    bay, and wheel well, and it dumps oxygen as effluent rather than using it
    for an emergency passenger oxygen system.

    9A 2001 NASA study indicated that two liquid nitrogen systems were the
    only ones that appeared capable of inerting all fuel tanks of a commercial
    aircraft full time.

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    could lead to arcing. Arcing can occur between a wire and structure or
    between different wire types. Wire chafing is a sign of degradation;
    chafing happens when the insulation around one wire rubs against a
    component tougher than itself (such as structure or control cable)
    exposing the wire conductor. This condition can lead to arcing. When
    arcing wires are too close to flammable materials or are flammable
    themselves, fires can occur.

    In general, wiring and wiring insulation degrade for a variety of reasons,
    including age, inadequate maintenance, chemical contamination, improper
    installation or repair, and mechanical damage. Vibration, moisture, and
    heat can contribute to and accelerate degradation. Consequences of wire
    systems failures include loss of function, smoke, and fire. Since most
    wiring is bundled and located in hidden or inaccessible areas, it is
    difficult to monitor the health of an aircraft's wiring system during
    scheduled maintenance using existing equipment and procedures. Failure
    occurrences have been documented in wiring running to the fuel tank, in
    the electronics equipment compartment, in the cockpit, in the ceiling of
    the cabin, and in other locations.

    To address the concerns with arcing, arc fault circuit breakers for
    aircraft use are being developed. The arc fault circuit breaker cuts power
    off as it senses a wire beginning to arc. It is intended to prevent
    significant damage before a failure develops into a full-blown arc, which
    can produce extremely localized heat, char insulation, and generally
    create problems in the wire bundles. Arc fault circuit protection devices
    would mitigate arcing events, but will not identify the wire breaches and
    degradation that typically lead up to these events.

    Status	FAA, the Navy, and the Air Force are jointly developing arc fault
    circuit breaker technology. Boeing is also developing a monitoring system
    to detect the status of and changes in wiring; and power shuts down when
    arcing is detected. This system may be able to protect wiring against both
    electrical overheating and arcing and is considered more advanced than the
    government's circuit breaker technology.

    FAA developed a plan called the Enhanced Airworthiness Program for
    Airplane Systems to address wiring problems, which includes development of
    arc fault circuit breaker technology and installation guidance along with
    proposals of new regulations. The plan provides means for enhancing safety
    in the areas of wire system design, certification, maintenance, research
    and development, reporting, and information sharing and

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    outreach. FAA also tasked an Aging Transport Systems Rule-making Advisory
    Committee to provide data, recommendations, and evaluation specifically on
    aging wiring systems. The new regulations being considered are entitled
    the Enhanced Airworthiness Program for Airplane Systems Rule and are
    expected by late-2005. Under this rule-making package, inspections would
    evaluate the health of wiring and all of its components for operation,
    such as connectors and clamps. Part of the system includes visual
    inspections of all wiring within arm's reach, enhanced by the use of
    hand-held mirrors. This improvement is expected to catch more wiring flaws
    than current visual inspection practices. Where visual inspections can not
    be assumed to detect damage, detailed inspections will be required. The
    logic process to establish proper inspections is called the Enhanced Zonal
    Analysis Procedure, which will be issued as an Advisory Circular. This
    procedure is specifically directed towards enhancing the maintenance
    programs for aircraft whose current program does not include tasks derived
    from a process that specifically considers wiring in all zones as the
    potential source of ignition of a fire.

    Additional development and testing will be required before advanced arc
    fault circuit breakers will be available for use on aircraft. The FAA
    currently is in the midst of a prototype program where arc fault circuit
    breakers are installed in an anticollision light system on a major air
    carrier's Boeing 737. The FAA and the Navy are currently analyzing tests
    of the circuit breakers to assess their reliability. The Society of
    Automotive Engineers is in the final stages of developing a Minimum
    Operating Performance Specification for the arc fault circuit breaker.

                                 Multisensor Detectors

    Background	Multisensor detectors, or "electronic noses," could combine one
    or more standard smoke detector technologies; a variety of sensors for
    detecting such gases as carbon monoxide, carbon dioxide, or hydrocarbon;
    and a thermal sensor to more accurately detect and locate overheated or
    burning materials. The sensors could improve existing fire detection by
    discovering and locating potential or actual fires sooner and reducing the
    incidence of false alarms. These "smart" sensors would ignore the
    "nuisance sources"

    Appendix V
    Summaries of Potential Fire Safety
    Advancements

    such as dirt, dust, and condensation that are often responsible for
    triggering false alarms in existing systems.10

    According to studies by FAA and the National Institute of Standards and
    Technology, many current smoke and fire detection systems are not
    reliable. A 2000 FAA study indicated that cargo compartment detection
    systems, for example, resulted in at least one false alarm per week from
    1988 through 1990 and a 200:1 ratio of false alarms to actual fires in the
    cargo compartment from 1995 through 1999. 11 FAA has since estimated a
    100:1 cargo compartment false alarm ratio, partly because reported actual
    incidents have increased According to FAA's Service Difficulty Report
    database,12 about 990 actual smoke and fire events were reported for
    2001.13

    Multisensor detectors could be wired or wireless and linked to a
    suppression system. One or several sensor signals or indicators could
    cause the crew to activate fire extinguishers in a small area or zone, a
    larger area, or an entire compartment, resulting in a more appropriate and
    accurate use of the fire suppressant. For example, in areas such as the
    avionics compartment, materials that can burn are relatively well-defined.
    Multisensor detectors the size of a postage stamp could be designed to
    detect smoldering fires in cables or insulation or in overheated equipment
    in that area. Placing the detectors elsewhere in the airplane could
    improve the crew's ability to respond to smoke or fire, including
    occurrences in hidden or inaccessible areas.

    Improved sensor detection technologies would both enhance safety by
    increasing crews' confidence in the reliability of alarms and reduce costs
    by avoiding the need to divert aircraft in response to false alarms. One

    10One type of smart sensor would analyze the light-scattering properties
    of the particles in the air to differentiate between smoke particles and
    nuisance sources.

    11Aircraft Cargo Compartment Smoke Detector Alarm Incidents on
    U.S.-Registered Aircraft, 1974-1999, DOT/FAA/AR-TN00/29 (Washington, D.C.:
    June 2000). The study indicated a generally increasing number of false
    alarms as the size of the fleet grew.

    12Operating requirements for all aircraft have been amended by a 2000
    final rule, whose deadline was recently extended for the third time, to
    report the occurrence or detection of failures, malfunctions, or defects
    concerning fire warning systems and false warnings of fire or smoke in the
    entire U.S. fleet.

    13According to FAA fire safety experts, most of these are contaminated air
    or smoke events in the cabin, detected by people, not by detectors.

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    study estimated the average cost of a diversion at $50,000 for a wide-body
    airplane and $30,000 for a narrow-body airplane. A diversion can also
    present safety concerns because of the possible increased risk of an
    accident and injuries to passengers and crew if there is (1) an emergency
    evacuation, (2) a landing at an unfamiliar airport, (3) a change to air
    traffic patterns, (4) a shorter runway, (5) inferior fire-fighting
    capability, (6) a loss of cargo load, or (7) inferior navigation aids. In
    2002, 258 unscheduled landings due to smoke, fire, or fumes occurred. In
    addition, 342 flights were interrupted; some of these flights had to
    return to the gate or abort a takeoff.

    FAA established basic detector performance requirements in 1965 and 1980.
    Detectors were to be made and installed in a manner that ensured their
    ability to resist, without failure, all vibration, inertia, and other
    loads to which they might normally be subjected; they also had to be
    unaffected by exposure to fumes, oil, water, or other fluids. Regulations
    in 1986 and 1998 further defined basic location and performance
    requirements for detectors in different areas of the cargo compartment. In
    1998, FAA issued a requirement for detection and extinguishment systems
    for one class of cargo compartments, which relied on oxygen starvation to
    control fires. This requirement significantly increased the number of
    detectors in use.

    Status	Multisenor detectors are not currently available because additional
    research is needed. Although they have been demonstrated in the laboratory
    and on the ground, they have not been flight-tested. FAA and NASA have
    multisensor detector research and development efforts under way and are
    working to develop "smart" sensors and criteria for their approval. FAA
    will also finish revising an Advisory Circular that establishes test
    criteria for detection systems, designed to ensure that they respond to
    fires, but not to nonfire sources. In addition, several companies
    currently market "smart" detectors, mostly for nonaviation applications.
    For example, thermal detection systems sense and count certain particles
    that initially boil off the surface of smoldering or burning material.

    A European consortium has been developing a system, FIREDETEX, that
    combines the use of multisensor detectors, onboard fuel tank inerting, and
    water-mist-plus-nitrogen fire suppression systems for commercial
    airplanes. This program and associated studies are still ongoing and
    flight testing is planned for the last quarter of calendar year 2003. The
    results of tests on this system are expected to be made public in early
    2004, and will

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    help to clarify the possible costs, benefits, and drawbacks of the
    combined system.

    Additional research, development, and testing will be required before
    multisensor technology is ready for use in commercial aviation. NASA, FAA,
    and private companies are pursuing various approaches. Some experts
    believe that some forms of multisensor technology could be in use in 5
    years. When these units become available, questions may arise about where
    their use will be required. For example, the Canadian Transportation
    Safety Board has recommended that some areas in addition to those
    currently designated as fire zones may need to be equipped with
    detectors.14 These include the electronics and equipment bay (typically
    below the floor beneath the cockpit and in front of the passenger cabin),
    areas behind interior wall panels in the cockpit and cabin areas, and
    areas behind circuit breaker and other electronic panels.

    Water Mist Fire Suppression

    Background	For over two decades, the aviation industry has evaluated the
    use of systems that spray water mist to suppress fires in airliner cabins,
    cargo compartments, and engine casings (see fig. 7). This effort was
    prompted, in part, by a need to identify an alternative to Halon, the
    primary chemical used to extinguish fires aboard airliners. With few
    exceptions, Halon is the sole fire suppressant installed in today's
    aircraft fire suppression systems. However, the production of Halon was
    banned under the 1987 Montreal Protocol on Substances that Deplete the
    Ozone Layer, and its use in many noncritical sectors has been phased out.
    Significant reserves of Halon remain, and its use is still allowed in
    certain "critical use" applications, such as aerospace,15 because no
    immediate viable replacement agent

    14This recommendation was one of several resulting from the Canadian
    Transportation Safety Board's investigation of the Swissair Flight 111
    crash.

    15A use is considered "critical" when a need exists to protect against
    fire or explosion risks in areas that would result in a serious threat to
    essential services or pose an unacceptable threat to life, the
    environment, or national security. Typical critical users are aerospace,
    certain petrochemical production processors, certain marine applications,
    and national defense.

    Appendix V
    Summaries of Potential Fire Safety
    Advancements

    exists. To enable the testing and further development of suitable
    alternatives to and substitutes for Halon, FAA has drafted detailed
    standards for replacements in the cargo and engine compartments. These
    standards typically require replacement systems to provide the same level
    of safety as the currently used Halon extinguishing system.

    Figure 7: Water Mist Nozzle and Possible Placement

    According to FAA and others in the aviation industry, successful water
    mist systems could provide benefits against an in-flight or postcrash
    fire, including

    o 	cooling the passengers, cabin surfaces, furnishings and overall cabin
    temperatures;

    o  decreasing toxic smoke and irritant gases; and

    Appendix V
    Summaries of Potential Fire Safety
    Advancements

    o  delaying or preventing "flashover" fires from occurring. 16

    In addition, a 1996 study prepared for the British Civil Aviation
    Authority examined 42 accidents and 32 survivability factors and found
    that cabin water spray was the factor that showed the greatest potential
    for reducing fatality and injury rates.17 In the early 1990s, a joint FAA
    and Civil Aviation Authority study found that cabin water mist systems
    would be highly effective in improving survivability during a postcrash
    fire.18 However, the cost of using these systems outweighed the benefits,
    largely because of the weight of the water that airliners would be
    required to carry to operate them. In the mid- and late-1990s, FAA and
    others began examining water mist systems in airliner cargo compartments
    to help offset the cost of a cabin water mist system because the water
    could be used or shared by both the cargo compartment and the cabin.
    European and U.S. researchers also designed systems that required much
    less water because they targeted specific zones within an aircraft to
    suppress fires rather than spraying water throughout the cabin or the
    cargo compartment.

    In 2000, Navy researchers found a twin-fluid system to be highly reliable
    and maintenance-free.19 Moreover, this system's delivery nozzles could be
    installed without otherwise changing cabin interiors. The Navy
    researchers' report recommended that FAA and NTSB perform follow-up
    testing leading to the final design and certification of an interior water
    mist fire suppression system for all passenger and cargo transport
    aircraft. Also in 2000, a European consortium began a collaborative
    research project

    16Flashover can occur in an airplane cabin fire when all exposed
    combustible surfaces reach ignition temperature more or less
    simultaneously. It is characterized by rapid increases in temperature,
    with smoke, toxic gases, and oxygen depletion creating a largely
    nonsurvivable environment.

    17R.G.W. Cherry & Associates, Analysis of Structural Factors Influencing
    the Survivability of Occupants in Aeroplane Accidents, Civil Aviation
    Authority, Paper 96011 (London: December 1996).

    18Increasing the Survival Rate in Aircraft Accidents: Impact Protection,
    Fire Survivability, and Evacuation, European Transport Safety Council
    (December 1996).

    19Twin-fluid systems use air, nitrogen, or another gas in combination with
    water. They require lower water supply pressure and bigger nozzle
    orifices.

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    called FIREDETEX, which combines multisensor fire detectors, water mist,
    and onboard fuel tank inerting into one fire detection and suppression
    system.20

    In 2001 and 2002, FAA tested experimental mist systems to determine what
    could meet its preliminary minimum performance standards for cargo
    compartment suppression systems. A system that combines water mist with
    nitrogen met these minimum standards. In this system, water and nitrogen
    "knock down" the initial fire, and nitrogen suppresses any deep-seated
    residual fire by inerting the entire compartment.21 In cargo compartment
    testing, this system maintained cooler temperatures than had either a
    plain water mist system or a Halon-based system.

    Status	Additional research and testing are needed before water mist
    technology can be considered for commercial aircraft. For example, the
    weight and relative effectiveness of any water mist system would need to
    be considered and evaluated. In addition, before it could be used in
    aircraft, the consequences of using water will need to be further
    evaluated. For example, Boeing officials noted that using a water mist
    fire suppression system in the cabin in a post crash fire might actually
    reduce passenger safety if the mist or fog creates confusion among the
    passengers, leading to longer evacuation times. Further, of concern is the
    possible shorting of electrical wiring and equipment and damage to
    aircraft interiors (e.g., seats, entertainment equipment, and insulation).
    Water cleanup could also be difficult and require special drying
    equipment.

    20Inerting involves reducing flammability in fuel tanks, which is
    discussed separately in this report.

    21Boeing commented that this more recent system would not pass the
    original cargo minimum performance standard, and Boeing disagrees with
    FAA's relaxing of the original standard.

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

                                    Fire-Safe Fuels

    Background	Burning fuel typically dominates and often overwhelms postcrash
    fire scenarios and causes even the most fire-resistant materials to
    burn.22 Fuel spilled from tanks ruptured upon crash impact often forms an
    easily ignitable fuel-air mixture. A more frequent fuel-related problem is
    the fuel tank explosion, in which a volatile fuel-air mixture inside the
    fuel tank is ignited, often by an unknown source. For example, it is
    believed that fuel tank explosions destroyed a Philippines Air 737 in
    1990, TWA Flight 800 in 1996, and a Thai Air 737 in 2001. Therefore,
    reducing the flammability of fuel could improve survivability in postcrash
    fires as well as reduce the occurrence of fuel tank explosions.

    Reducing fuel flammability involves limiting the volatility23 of fuel and
    the rate at which it vaporizes.24 Liquid fuel can burn only when enough
    fuel vapor is mixed with air. If the fuel cannot vaporize, a fire cannot
    occur. This principle is behind the development of higher-flashpoint fuel,
    whose use can decrease the likelihood of a fuel tank explosion. The flash
    point is the lowest temperature at which a liquid fuel produces enough
    vapor to ignite in the presence of a source of ignition-the lower the
    flash point, the greater the risk of fire. If the fuel is volatile enough,
    however, and air is sucked into the fuel tank area upon crash impact,
    limiting the fuel's vaporization can prevent a burnable mixture from
    forming. This principle supports the use of additives that modify the
    viscosity of fuel to limit postcrash fires; for example, antimisting
    kerosene contains such additives.

    22An average widebody aircraft carries 50,000 gallons of aviation fuel at
    takeoff.

    23Fuels function by releasing combustible gases. Indicators of volatility
    include a fuel's boiling point (the higher the boiling point, the less
    volatile the fuel) and vapor pressure (the higher the vapor pressure, the
    more volatile the fuel). Therefore, raising the temperature can increase
    volatility. A highly volatile fuel is more likely to form a flammable or
    explosive mixture with air than a nonvolatile fuel. By definition, gases
    are volatile. Liquid fuels either are sufficiently volatile at room
    temperature to produce combustible vapor (ethanol, petrol) or they produce
    sufficient combustible vapors when heated (kerosene).

    24The fuel vaporization rate is the minimum temperature to which the pure
    liquid fuel must be heated so that the vapor pressure is high enough for
    an explosive mixture to be formed with air--then the liquid is allowed to
    evaporate and is brought into contact with a flame, spark, or hot
    filament. Flash points are lower than ignition temperatures.

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    According to FAA and NASA, however, these additives do nothing to prevent
    fuel tank explosions.

    From the early 1960s to the mid-1980s, FAA conducted research on fuel
    safety. The Aviation Safety Act of 1988 required that FAA undertake
    research on low-flammability aircraft fuels, and, in 1993, FAA developed
    plans for fuel safety research. In 1996, a National Research Council
    experts' workshop on aviation fuel summarized existing fuel safety
    research efforts. The participants concluded that although postcrash
    fuel-fed aircraft fires had been researched, limited progress had been
    achieved and little work had been published.

    As part of FAA's research, fuels have been modified with thickening
    polymer additives to slow down vaporization in crashes. Participants in
    the 1996 National Research Council workshop identified several long-term
    research goals for consideration in developing modified fuels and fuel
    additives to improve fire safety. They also agreed that a combination of
    effective fire-safe fuel additives could probably be either selected or
    designed, provided that fuel performance requirements were identified in
    advance. In addition, they agreed that existing aircraft designs that
    reduce the chance of fuel igniting do not present major barriers to the
    implementation of a fire-safe fuel.

    A 1996 European Transport Safety Council report suggested that antimisting
    kerosene be at least partially tested on regular military transport
    flights (e.g., in one tank, feeding one engine) to demonstrate its
    operational compatibility. The report also recommended the consideration
    of a study comparing the costs of the current principal commercial fuel
    and the special, higher-flashpoint fuel used by the Navy. According to
    NASA and FAA fire-safe fuels experts, military fuel is much harder to burn
    in storage or to ignite in a pan because of its lower volatility; however,
    it is just as flammable as aviation fuel when it is sprayed into an engine
    combustor.

    Status	Fire-safe fuels are not currently available and are in the early
    stages of research and development. In January 2002, NASA opened a
    fire-safe fuels research branch at its Glenn Research Center in Ohio.
    NASA-Glenn is conducting aviation fuel research that evaluates fuel vapor
    flammability in conjunction with FAA's fuel tank inerting program,
    including the measurement of fuel "flash points." NASA is examining the
    effects of

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    surfactants, gelling agents, and chemical composition changes on the
    vaporization and pressure characteristics of jet fuel.25

    In addition to FAA's and NASA's research, some university and industry
    researchers have made progress in developing fire-safe fuels. Many use
    advanced analytical, computational modeling technologies to inform their
    research. A council of producers and users of fuels is also coordinating
    research on ways to use such fuels. NASA fuel experts remain optimistic
    that small changes in fuel technologies can have a big impact on fuel
    safety.

    Developing fire-safe fuels will require much more research and testing.
    There are significant technical difficulties associated with creating a
    fuel that meets aviation requirements while meaningfully decreasing the
    flammability of the fuel.

    Thermal Acoustic Insulation Materials

    Background 	To keep an airplane quieter and warmer, a layer of thermal
    acoustic insulation material is connected to paneling and walls throughout
    the aircraft. This insulation, if properly designed, can also prevent or
    limit the spread of an in-flight fire. In addition, thermal acoustic
    insulation provides a barrier against a fire burning through the cabin
    from outside the airplane's fuselage (See fig. 8.). Such a fire, often
    called a postcrash fire, may occur when fuel is spilled on the ground
    after a crash or an impact.

    25A surfactant, or surface-active agent, is a soluble compound that
    reduces the surface tension of liquids, or reduces interfacial tension
    between two liquids or a liquid and a solid. A gelling agent is a fuel
    "thickener."

    Appendix V
    Summaries of Potential Fire Safety
    Advancements

    Figure 8: Fire Insulation Blankets

    While this thermal acoustic insulation material could help prevent the
    spread of fire, some of the insulation materials that have been used in
    the past have contributed to fires. For example, FAA indicated that an
    insulation material, called metallized Mylar(R), contributed to at least
    six in-flight fires. Airlines have stopped using this material and are
    removing it from existing aircraft.

    FAA's two main efforts in this area are directed toward preventing fatal
    in-flight fire and improving postcrash fire survivability.

    o 	Since 1998, FAA has been developing test standards for preventing
    in-flight fires in response to findings that fire spread on some thermal
    acoustic insulation blanket materials. In 2000, FAA issued a notice of
    proposed rule-making that outlined new flammability test criteria for
    in-flight fires. FAA's in-flight test standards require thermal acoustic

    Appendix V
    Summaries of Potential Fire Safety
    Advancements

    insulation materials to protect passengers. According to the standards,
    insulation materials installed in airplanes will not propagate a fire if
    ignition occurs.

    o 	FAA is also developing more stringent burnthrough test standards for
    postcrash fires. FAA has been studying the penetration of the fuselage by
    an external fire-known as fuselage burnthrough-since the late 1980s and
    believes that improving the fire resistance of thermal acoustic insulation
    could delay fuselage burnthrough. In laboratory tests conducted from 1999
    through 2002, an FAA-led working group determined that insulation is the
    most potentially effective and practical means of delaying the spread of
    fire or creating a barrier to burnthrough. In 2002, FAA completed draft
    burnthrough standards outlining a proposed methodology for testing thermal
    acoustic insulation. The burnthrough standards would protect passengers
    and crews by extending by at least 4 minutes the time available for
    evacuation in a postcrash fire.

    Various studies have estimated the potential benefits from both test
    standards:

    o 	A 1999 study of worldwide aviation accidents from 1966 through 1993
    estimated that about 10 lives per year would have been saved if protection
    had provided an additional 4 minutes for occupants to exit the airplane.

    o 	A 2000 FAA study estimated that about 37 U.S. fatalities would be
    avoided between 2000 and 2019 through the implementation of both proposed
    standards.26

    o 	A 2002 study by the British Civil Aviation Authority of worldwide
    aviation accidents from 1991 through 2000 estimated that at least 34 lives
    per year would have been saved if insulation had met both proposed
    standards.

    26FAA's benefit estimate, based on $2.7 million per life saved, ranges
    from $37.7 million to $231.5 million, discounted to present value, based
    partially on 37.2 deaths avoided from its 2000 study. FAA could not
    quantify benefits from flame propagation requirements, but indicated that
    avoiding an accident with 169 passenger fatalities would avert a $231.5
    million loss (not including the cost of the plane).

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    Status	Insulation designed to replace metallized Mylar(R) is currently
    available. A 2000 FAA airworthiness directive gave the airlines 5 years to
    remove and replace metallized Mylar(R) insulation in 719 affected
    airplanes. Replacement insulation is required to meet the in-flight
    standard and will be installed in these airplanes by mid-2005. In that
    airworthiness directive, FAA indicated that it did not consider other
    currently installed insulation to constitute an unsafe condition.

    Thermal acoustic insulation is currently available for installation on
    commercial airliners. This insulation has been demonstrated to reduce the
    chance of fatal in-flight fires and to improve postcrash fire
    survivability. On July 31, 2003, FAA issued a final rule requiring that
    after September 2, 2005, all newly manufactured airplanes having a seating
    capacity of more than 20 passengers or over 6,000 pounds must use thermal
    acoustic insulation that meets more stringent standards for how quickly
    flames can spread.27 In addition, for aircraft of this size manufactured
    before September 2, 2003, replacement insulation in the fuselage must also
    meet the new, higher standard.

    Research is continuing to develop thermal acoustic insulation that
    provides better in-flight and burnthrough protection. Even when this
    material is available, the high cost of retrofitting airplanes may limit
    its use to newly manufactured aircraft. For example, FAA estimates that
    the metallized Mylar(R) retrofit alone will cost a total of $368.4
    million, discounted to present value terms, for the 719 affected
    airplanes. Because thermal acoustic insulation is installed throughout the
    pressurized section of the airplane for the life of its service,
    retrofitting the entire fleet would cost several billion dollars.

    Ultra-Fire-Resistant Polymers

    Background	Polymers are used in aircraft in the form of lightweight
    plastics and composites and are selected on the basis of their estimated
    installed cost,

    27Improved Flammability Standards for Thermal/Acoustic Insulation
    Materials Used in Transport Category Airplanes; Final Rule, FAA/DOT (14
    C.F.R. parts 25, 91, et al.).

    Appendix V
    Summaries of Potential Fire Safety
    Advancements

    weight, strength, and durability. Most of the aircraft cabin is made of
    polymeric material. In the event of an in-flight or a postcrash fire, the
    use of polymeric materials with reduced flammability could give passengers
    and crew more time to evacuate by delaying the rate at which the fire
    spreads through the cabin.

    FAA researchers are developing better techniques to measure the
    flammability of polymers and to make polymers that are ultra fire
    resistant. Developing these materials is the long-term goal of FAA's Fire
    Research Program, which, if successful, will "eliminate burning cabin
    materials as a cause of death in aircraft accidents." Materials being
    improved include composite and adhesive resins, textile fibers, rubber for
    seat cushions, and plastics for molded parts used in seats and passenger
    electronics. (See fig. 9.)

    Figure 9: Flammable Cabin Materials and Small-scale Material Test Device

    Adding flame-retardant substances to existing materials is one way to
    decrease their flammability. For example, some manufacturers add
    substances that release water when they reach a high temperature. When a
    material, such as wiring insulation, is heated or burns, the water acts to
    absorb the heat and cools down the fire. Other materials are designed to
    become surface-scorched on exposure to fire, causing a layer of char to
    protect the rest of the material from burning. Lastly, adding a type of
    clay can have a flame-retardant effect. In general, these fire-retardant
    polymers are formulated to pass an ignition test but do not meet FAA's
    criterion for ultra fire resistance, which is a 90 percent reduction in
    the rate at which the

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    untreated material would burn. To meet this strict requirement, FAA is
    developing new "smart" polymers that are typical plastics under normal
    conditions but convert to ultra-fire-resistant materials when exposed to
    an ignition source or fire.

    FAA has adopted a number of flammability standards over the last 30 years.
    In 1984, FAA passed a retrofit rule that replaced 650,000 seat cushions
    with flame-retardant seat cushions at a total cost of about $75 million.
    The replacement seat cushions were found to delay cabin flashover by 40 to
    60 seconds. Fire-retardant seat cushions can also prevent ramp and
    in-flight fires that originate at a seat and would otherwise burn out of
    control if left unattended. In 1986 and 1988, FAA set maximum allowable
    levels of heat and smoke from burning interior materials to decrease the
    amount of smoke that they would release in a postcrash fire. These
    standards affected paneling in all newly manufactured aircraft. Airlines
    and airframe manufacturers invested several hundred million dollars to
    develop these new panels.

    Status	Ultra-fireresistant polymers are not currently available for use on
    commercial airliners. These polymers are still in the early stages of
    research and development. To reduce the cost and simplify the testing of
    new materials, FAA is employing a new technique to characterize the
    flammability and thermal decomposition of new products; this technique
    requires only a milligram of sample material. The result has been the
    discovery of several new compositions of matter (including "smart"
    polymers). The test identifies key thermal and combustion properties that
    allow rapid screening of new materials.28 From these materials, FAA plans
    to select the most promising and work with industry to make enough of the
    new polymers to fabricate full-scale cabin components like sidewalls and
    stowage bins for fire testing.

    FAA's phased research program includes the selection in 2003 of a small
    number of resins, plastics, rubbers, and fibers on the basis of their
    functionality, cost, and potential to meet fire performance guidelines. In
    2005, FAA plans to fabricate decorative panels, molded parts, seat
    cushions, and textiles for testing from 2007 through 2010. Full-scale
    testing

    28These methods test the heat release rate, total heat of combustion of
    the volatiles, thermal stability, char yield, decomposition process, and
    rate of decomposition.

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    is scheduled for 2011 but is contingent upon the availability of program
    funds and commercial interest from the private sector.

    Research continues on ultra-fire-resistant polymers that will increase
    protection against in-flight fires and cabin burnthrough. According to an
    FAA fire research expert, issues facing this research include (1) the
    current high cost of ultra-fire-resistant polymers; (2) difficulties in
    producing ultra-fire-resistant polymers with low to moderate processing
    temperatures, good strength and toughness, and colorability and
    colorfastness; and (3) gaps in understanding the relationship between
    material properties and fire performance and between chemical composition
    and fire performance, scaling relationships, and fundamental
    fire-resistance mechanisms. In addition, once the materials are developed
    and tested, getting them produced economically and installed in aircraft
    will become an issue. It is expected that such new materials with ultra
    fire resistance would be more expensive to produce and that the market for
    such materials would be uncertain.

    Airport Rescue and Fire-Fighting Operations

    Background	Because of the fire danger following a commercial airplane
    crash, having airport rescue and fire-fighting operations available can
    improve the chances of survival for the people involved. Most airplane
    accidents occur during takeoff or landing at the airport or in the
    surrounding community. A fire outside the airplane, with its tremendous
    heat, may take only a few minutes to burn through the airplane's outside
    shell. According to FAA, firefighters are responsible for creating an
    escape path by spraying water and chemicals on the fire to allow the
    passengers and crew to evacuate the airplane. Firefighters use one or more
    trucks to extinguish external fires, often at great personal risk, and use
    hand-held attack lines when attempting to put out fires within the
    airplane fuselage. (See fig. 10). Fires within the fuselage are considered
    difficult to control with existing equipment and procedures because they
    involve complex conditions, such as smoke-laden toxic gases and high
    temperatures in the passenger cabin. FAA has taken actions to control both
    internal and external postcrash fires,

    Appendix V
    Summaries of Potential Fire Safety
    Advancements

    including requiring major airports to have airport rescue and
    fire-fighting operations.

    In 1972, FAA first proposed regulations to ensure that major airports have
    a minimal level of airport rescue and fire-fighting operations. Some
    changes to these regulations were made in 1988. The regulations establish,
    among other things, equipment standards, annual testing requirements for
    response times, and operating procedures. The requirements depend on both
    the size of the airport and the resources the locality has agreed to make
    available as needed.

    In 1997, FAA compared airport rescue and fire-fighting missions and
    standards for civilian airports with DOD's for defense installations and
    reported that DOD's requirements were not applicable to civilian airports.
    In 1988, and again in 1998, Transport Canada Civil Aviation also studied
    its rescue and fire-fighting operations and concluded that the expenditure
    of resources for such unlikely occurrences was difficult to justify from a
    benefit-cost perspective. This conclusion highlighted the conflict between
    safety and cost in attempting to define rescue and fire-fighting
    requirements.

    A coalition of union organizations and others concerned about aviation
    safety released a report critical of FAA's standards and operational
    regulations in 1999. According to the report, FAA's airport rescue and
    fire-fighting regulations were outdated and inadequate.

                                       Appendix V
                           Summaries of Potential Fire Safety
                                      Advancements

    Status	In 2002, FAA incorporated measures recommended by NTSB into FAA's
    Aeronautical Information Manual Official Guide to Basic Flight Information
    and Air Traffic Control Procedures.29 These measures (1) designate a radio
    frequency at most major airports to allow direct communication between
    airport rescue and fire-fighting personnel and flight crewmembers in the
    event of an emergency and (2) specify a universal set of hand signals for
    use when radio communication is lost.

    In March 2001, FAA responded to the reports criticizing its airport rescue
    and fire-fighting standards by tasking its Aviation Regulatory Advisory
    Committee to review the agency's rescue and fire-fighting requirements to
    identify measures that could be added, modified, or deleted. In 2003, the
    committee is expected to propose requirements for the number of trucks,
    the amount of fire extinguishing agent, vehicle response times, and
    staffing at airports and to publish its findings in a notice of proposed
    rule-making. Depending on the results of this FAA review, additional
    resources may be needed at some airports. The overall cost of improving
    airport rescue and fire-fighting response capabilities could be a
    significant barrier to the further development of regulations. For
    example, some in the aviation industry are concerned about the costs of
    extending requirements to smaller airports and of appropriately equipping
    all airports with resources. According to FAA, extending federal safety
    requirements to some smaller airports would cost at least $2 million at
    each airport initially and $1 million annually thereafter.

    29This manual is designed to provide the aviation community with basic
    flight information and air traffic control procedures for use in the
    National Airspace System of the United States.

    Appendix VI

    Summaries of Potential Improved Evacuation Safety Advancements

    This appendix presents information on the background and status of
    potential advancements in evacuation safety that we identified, including
    the following:

    o  improved passenger safety briefings;

    o  exit seat briefings;

    o  photo-luminescent floor track marking;

    o  crewmember safety and evacuation training;

    o  acoustic attraction signals;

    o  smoke hoods;

    o  exit slide testing;  o  overwing exit doors;

    o  evacuation procedures for very large transport aircraft; and

    o  personal flotation devices.

    Passenger Safety Briefings

    Background 	Federal regulations require that passengers receive an oral
    briefing prior to takeoff on safety aspects of the upcoming flight. FAA
    also requires that oral briefings be supplemented with printed safety
    briefing cards that pertain only to that make and model of airplane and
    are consistent with the air carrier's procedures. These two safety
    measures must include information on smoking, the location and operation
    of emergency exits, seat belts, compliance with signs, and the location
    and use of flotation devices. In addition, if the flight operates above
    25,000 feet mean sea level, the briefing and cards must include
    information on the emergency use of oxygen.

    FAA published an Advisory Circular in March 1991 to guide air carriers'
    development of oral safety briefings and cards. Primarily, the circular

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    defines the material that must be covered and suggests material that FAA
    believes should be covered. The circular also discusses the difficulty in
    motivating passengers to attend to the safety information and suggests
    making the oral briefing and safety cards as attractive and interesting as
    possible to increase passengers' attention. The Advisory Circular
    suggests, for example, that flight attendants be animated, speak clearly
    and slowly, and maintain eye contact with the passengers. Multicolored
    safety cards with pictures and drawings should be used over black and
    white cards. Finally, the circular suggests the use of a recorded
    videotape briefing because it ensures a complete briefing with good
    diction and allows for additional visual information to be presented to
    the passengers. (See fig. 11.)

    Status 	Despite efforts to improve passengers' attention to safety
    information, a large percentage of passengers continue to ignore preflight
    safety briefings and safety cards, according to a study NTSB conducted in
    1999. Of 457

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    passengers polled, 54 percent (247) reported that they had not watched the
    entire briefing because they had seen it before. An additional 70
    passengers indicated that the briefing provided common knowledge and
    therefore there was no need to watch it. Of 431 passengers who answered a
    question about whether they had read the safety card, 68 percent (293)
    indicated that they had not, many of them stating that they had read
    safety cards on previous flights.

    Safety briefings and cards serve an important safety purpose for both
    passengers and crew. They are intended to prepare passengers for an
    emergency by providing them with information about the location and
    operation of exits and emergency equipment that they may have to
    operate-and whose location and operation may differ from one airplane to
    the next. Well-briefed passengers will be better prepared in an emergency,
    thereby increasing their chances of surviving and lessening their
    dependence on the crew for assistance.

    In its emergency evacuation study, NTSB recommended that FAA instruct
    airlines to "conduct research and explore creative and effective methods
    that use state-of-the-art technology to convey safety information to
    passengers."1 NTSB further recommended "the presented information include
    a demonstration of all emergency evacuation procedures, such as how to
    open the emergency exits and exit the aircraft, including how to use the
    slides." That research found that passengers often view safety briefings
    and cards as uninteresting and the information as intuitive. FAA has
    requested that commercial carriers explore different ways to present the
    materials to their passengers, adding that more should be done to educate
    passengers about what to do after an accident has occurred.

                                   Exit Seat Briefing

    Background	Passengers seated in an exit row may be called on to assist in
    an evacuation. Upon a crewmember's command or a personal assessment of
    danger, these passengers must decide if their exit is safe to use and then
    open their exit hatch or door for use during an evacuation. In October
    1990,

    1NTSB, Safety Study: Emergency Evacuation of Commercial Airlines,
    [A-00-86] (Washington, D.C.: 2001).

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    FAA required airlines to actively screen passengers occupying exit seats
    for "suitability" and to administer one-on-one briefings on their
    responsibilities. This rule does not require specific training for exit
    seat occupants, but it does require that the occupants be duly informed of
    their distinct obligations.

    Status	According to NTSB, preflight briefings of passengers in exit rows
    could contribute positively to a passenger evacuation. In a 1999 study,
    NTSB found that the individual briefings given to passengers who occupy
    exit seats have a positive effect on the outcome of an aircraft
    evacuation. The studies also found that as a result of the individualized
    briefings, flight attendants were better able to assess the suitability of
    the passengers seated in the exit seats.

    According to FAA's Flight Standards Handbook Bulletin for Air
    Transportation, several U.S. airlines have identified specific cabin
    crewmembers to perform "structured personal conversations or briefings,"
    designed to equip and prepare passengers in exit seats beyond the general
    passenger briefing. Also, the majority of air carriers have procedures to
    assist crewmembers with screening passengers seated in exit rows.

    FAA's 1990 rule requires that passengers seated in exit rows be provided
    with information cards that detail the actions to be taken in the case of
    an emergency. However, individual exit row briefings, such as those
    recommended by NTSB, are not required. Also included on the information
    cards are provisions for a passenger who does not wish to be seated in the
    exit row to be reseated. Additionally, carriers are required to assess the
    exit row passenger's ability to carry out the required functions. The
    extent of discussion with exit row passengers depends on each airline's
    policy.

    Photo-luminescent Floor Track Marking

    Background	In June 1983, an Air Canada DC-9 flight from Dallas to Toronto
    was cruising at 33,000 feet when the crew reported a lavatory fire. An
    emergency was declared, and the aircraft made a successful emergency
    landing at the Cincinnati Northern Kentucky International Airport. The
    crew initiated an

    Appendix VI
    Summaries of Potential Improved Evacuation
    Safety Advancements

    evacuation, but only half of the 46 persons aboard were able to escape
    before becoming overcome by smoke and fire. In its investigation of this
    accident, NTSB learned that many of the 23 passengers who died might have
    benefited from floor tracking lighting. As a result, NTSB recommended that
    airlines be equipped with floor-level escape markings. FAA determined that
    floor lighting could improve the evacuation rate by 20 percent under
    certain conditions, and FAA now requires all airliners to have a row of
    lights along the floor to guide passengers to the exit should visibility
    be reduced by smoke.

    On transport category aircraft, these escape markings, called floor
    proximity marking systems, typically consist primarily of small electric
    lights spaced at intervals on the floor or mounted on the seat assemblies,
    along the aisle. The requirement for electricity to power these systems
    has made them vulnerable to a variety of problems, including battery and
    wiring failures, burned-out light bulbs, and physical disruption caused by
    vibration, passenger traffic, galley cart strikes, and hull breakage in
    accidents. Attempts to overcome these problems have led to the proposal
    that nonelectric, photo-luminescent (glow-in-the-dark) materials be used
    in the construction of floor proximity marking systems. The elements of
    these new systems are "charged" by the normal airplane passenger cabin
    lighting, including the sunlight that enters the cabin when the window
    shades are open during daylight hours. (See fig. 12.)

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    Status	Floor track marking using photo-luminescent materials is currently
    available but not required for U.S. commercial airliners. Performance
    demonstrations of photo-luminescent technology have found that strontium
    aluminate photo-luminescent marking systems can be effective in providing
    the guidance for egress that floor proximity marking systems are intended
    to achieve. According to industry and government officials, such
    photo-luminescent marking systems are also cheaper to install than
    electric light systems and require little to no maintenance. Moreover,
    photo-luminescent technology weighs about 15 to 20 pounds less than
    electric light systems and, unlike the electric systems, illuminates both
    sides of the aisle, creating a pathway to the exits.

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    Photo-luminescent floor track marking technology is mature and is
    currently being used by a small number of operators, mostly in Europe. In
    the United States, Southwest Airlines has equipped its entire fleet with
    the photo-luminescent system. However, the light emitted from
    photo-luminescent materials is not as bright as the light from
    electrically operated systems. Additionally, the photo-luminescent
    materials are not as effective when they have not been exposed to light
    for an extended period of time, as after a long overseas nighttime flight.
    The estimated retail price of an entire system, not including the
    installation costs, is $5,000 per airplane.

    Crewmember Safety and Evacuation Training

    Background	FAA requires crewmembers to attend annual training to
    demonstrate their competency in emergency procedures. They have to be
    knowledgeable and efficient while exercising good judgment. Crewmembers
    must know their own duties and responsibilities during an evacuation and
    be familiar with those of their fellow workers so that they can take over
    for others if necessary.

    The requirements for emergency evacuation training and demonstrations were
    first established in 1965. Operators were required to conduct full-scale
    evacuation demonstrations, include crewmembers in the demonstrations, and
    complete the demonstrations in 2 minutes using 50 percent of the exits.
    The purpose of the demonstrations was to test the crewmembers' ability to
    execute established emergency evacuation procedures and to ensure the
    realistic assignment of functions to the crew. A full-scale demonstration
    was required for each type and model of airplane when it first started
    passenger-carrying operations, increased its passenger seating capacity by
    5 percent or more, or underwent a major change in the cabin interior that
    would affect an emergency evacuation. Subsequently, the time allowed to
    evacuate the cabin during these tests was reduced to 90 seconds.

    The aviation community took steps in the 1990s to develop a program called
    Crew Resource Management that focuses on overall improvements in
    crewmembers' performance and flight safety strategies, including those

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    for evacuation. FAA officials told us that they plan to emphasize the
    importance of effective communication between crewmembers and are
    considering updating a related Advisory Circular. Effective communication
    between cockpit and cabin crew are particularly important with the added
    security precautions being taken after September 11, 2001, including the
    locking the cockpit door during flight.

    Status	The traditional training initiative now has an advanced curriculum,
    Advanced Crew Resource Management. According to FAA, this comprehensive
    implementation package includes crew resource management procedures,
    training for instructors and evaluators, training for crewmembers, a
    standardized assessment of the crew's performance, and an ongoing
    implementation process. This advanced training was designed and developed
    through a collaborative effort between the airline and research
    communities. FAA considers training to be an ongoing development process
    that provides airlines with unique crew resource management solutions
    tailored to their operational demands. The design of crew resource
    management procedures is based on principles that require an emphasis on
    the airline's specific operational environment. The procedures were
    developed to emphasize these crew resource management elements by
    incorporating them into standard operating procedures for normal as well
    as abnormal and emergency flight situations.

    Because commercial airliner accidents are rare, crewmembers must rely on
    their initial and recurrent training to guide their actions during an
    emergency. Even in light of advances and initiatives in evacuation
    technology, such as slides and slide life rafts, crewmembers must still
    assume a critical role in ensuring the safe evacuation of their
    passengers. Airline operators have indicated that it is very costly for
    them to pull large numbers of crewmembers off-line to participate in
    training sessions.

    FAA officials told us that improving flight and cabin crew communication
    holds promise for ensuring the evacuation of passengers during an
    emergency. To improve this communication and coordination between flight
    and cabin crew, FAA plans to update the related Advisory Circular, oversee
    training, and charge FAA inspectors with monitoring air carriers during
    flights to see that improvements are being implemented. In addition, FAA
    is enhancing its guidance to air carriers on preflight briefings for
    flight crews to sharpen their responses to emergency situations and
    mitigate passengers' confusion. FAA expects this guidance to bolster the
    use and quality of preflight briefings between pilots and flight
    attendants on

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    security, communication, and emergency procedures. According to FAA, these
    briefings have been shown to greatly improve the flight crew's safety
    mind-set and to enhance communication.

    Acoustic Attraction Signals

    Background	Acoustic attraction signals make sounds to help people locate
    the doors in smoke, darkness, or when lights and exit signs are obscured.
    When activated, the devices are intended to help people to determine the
    direction and approximate distance of the sound-and of the door. Examples
    of audio attraction signals include recorded speech sounds, broadband
    multifrequency sounds ("white noise"), or alarm bells.

    Research to determine if acoustic attraction signals can be useful in
    aircraft evacuation has included, for example, FAA's Civil Aeromedical
    Institute testing of recorded speech sounds in varying pitches, using
    phrases such as "This way out," "This way," and "Exit here." Researchers
    at the University of Leeds developed Localizer Directional Sound beacons,
    which combine broadband, multifrequency "white noise" of between 40Hz and
    20kHz with an alerting sound of at least one other frequency, according to
    the inventor (see fig. 13).

    Note: Acoustic signaling device is of the type used near building exits.

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    The FAA study noted above of acoustic attraction signals found that in the
    absence of recorded speech signals, the majority of participants
    evacuating a low-light-level, vision-obscured cabin will head for the
    front exit or will follow their neighbors. In contrast, participants
    exposed to recorded speech sounds will select additional exits, even those
    in the rear of the airplane. During aircraft trials conducted by Cranfield
    University and University of Greenwich researchers, tests of directional
    sound beacons found that under cabin smoke conditions, exits were used
    most efficiently when the cabin crew gave directions and the directional
    sound beacons were activated. With this combination, the distribution of
    passengers to the available exits was better than with cabin crew
    directions alone, sound beacons alone, no cabin crew directions, or no
    sound beacons. Researchers found that passengers were able to identify and
    move toward the closest sound source inside the airplane cabin and to
    distinguish between two closely spaced loudspeakers. However, in 2001,
    Airbus conducted several evacuation test trials of audio attraction
    signals using an A340 aircraft. According to Airbus, the acoustic
    attraction signals did not enhance passengers' orientation, and, overall,
    did not contribute to passengers' safety.

    Status 	While acoustic attraction signals are currently available, further
    research is needed to determine if their use is warranted on commercial
    airliners. FAA, Transport Canada Civil Aviation, and the British Civilian
    Aviation Authority do not currently mandate the use of acoustic attraction
    signals. The United Kingdom's Air Accidents Investigation Branch made a
    recommendation after the fatal Boeing 737 accident at Manchester
    International Airport in 1985 that research be undertaken to assess the
    viability of audio attraction signals and other evacuation techniques to
    assist passengers impaired by smoke and toxic or irritant gases. The
    Civilian Aviation Authority accepted the recommendation and sponsored
    research at Cranfield University; however, it concluded from the research
    results that the likely benefit of the technology would be so small that
    no further action should be taken, and the recommendation was closed in
    1992.

    The French Direction Generale de l'Aviation Civile funded aircraft
    evacuation trials using directional sound beacons in November 2002, with
    oversight by the European Joint Aviation Authorities. The trials were
    conducted at Cranfield University's evacuation simulator with British
    Airways cabin crew and examined eight trial evacuations by two groups of
    `passengers.' The study surveyed the participants' views on various
    aspects of their evacuation experience and measured the overall time to
    evacuate.

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    The speed of evacuation was found to be biased by the knowledge
    passengers' gained in the four successive trials, and by variations in the
    number of passengers participating on the 2 days (155 and 181). The four
    trials by each of the two groups of passengers also involved different
    combinations of crew and sound in each. The study concluded that the
    insufficient number of test sessions further contributed to bias in the
    results, and that further research would be needed to determine whether
    the devices help to speed overall evacuation.

    Further research and testing are needed before acoustic attraction signals
    can be considered for widespread airline use. The signals may have
    drawbacks that would need to be addressed. For example, the Civil Aviation
    Authority found that placing an audio signal in the bulkhead might
    disorient or confuse the first few passengers who have to pass and then
    move away from the sound source to reach the exit. Such hesitation slowed
    passengers' evacuation during testing. The researchers at Cranfield
    University trials in 1990 concluded that an acoustic sound signal did not
    improve evacuation times by a statistically significant amount, suggesting
    that the device might not be cost-effective.

                                      Smoke Hoods

    Background	Smoke hoods are designed to provide the user with breathable,
    filtered air in an environment of smoke and toxic gases that would
    otherwise be incapacitating. More people die from smoke and toxic gases
    than from fire after an air crash. Because only a few breaths of the
    dense, toxic smoke typically found in aircraft fires can render passengers
    unconscious and prevent their evacuation, the wider use of smoke hoods has
    been investigated as a means of preventing passengers from being overcome
    by smoke and of giving them enough breathable air to evacuate. However,
    some studies have found that smoke hoods are only effective in certain
    types of fires and in some cases may slow the evacuation of cabin
    occupants.

    As shown in figure 14, a filter smoke hood can be a transparent bag worn
    over the head that fits snugly at the neck and is coated with
    fire-retardant material; it has a filter but no independent oxygen source
    and can provide breathable air by removing some toxic contaminants from
    the air for a period ranging from several minutes to 15 minutes, depending
    on the

    Appendix VI
    Summaries of Potential Improved Evacuation
    Safety Advancements

    severity and type of air contamination. The hood has a filter to remove
    carbon monoxide-a main direct cause of death in fire-related commercial
    airplane accidents, as well as hydrogen cyanide-another common cause of
    death, sometimes from incapacitation that can prevent evacuation. Hoods
    also filter carbon dioxide, chlorine, ammonia, acid gases such as hydrogen
    chloride and hydrogen sulfide, and various hydrocarbons, alcohols, and
    other solvents. Some hoods also include a filter to block particulate
    matter. One challenge is where to place the hoods in a highly accessible
    location near each seat.

    Appendix VI
    Summaries of Potential Improved Evacuation
    Safety Advancements

    Certain smoke hoods have been shown to filter out many contaminants
    typically found in smoke from an airplane cabin fire and to provide some
    temporary head protection from the heat of fire. In a full-scale FAA test
    of cabin burnthrough, toxic gases became the driving factor determining
    survivability in the forward cabin, reaching lethal levels minutes before
    the smoke and temperature rose to unsurvivable levels.

    A collaborative effort to estimate the potential benefits of smoke hoods
    was undertaken in 1986 by the British Civil Aviation Authority (CAA), the

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    Federal Aviation Administration, the Direction Generale de l'Aviation
    Civile (France) and Transport Canada Civil Aviation. The resulting 1987
    study examined the 20 accidents where sufficient data was available out of
    74 fire-related accidents worldwide from 1966 to 1985. The results were
    sensitive to assumptions regarding extent of use and delays due to putting
    on smoke hoods. The study concluded that smoke hoods could significantly
    extend the time available to evacuate an aircraft and would have saved
    approximately 179 lives in the 20 accidents studied, assuming no delay in
    donning smoke hoods. Assuming a 10 percent reduction in the evacuation
    rate due to smoke hood use would have resulted in an estimated 145 lives
    saved in the 20 accidents with adequate data. A 15 second delay in donning
    the hoods would have saved an estimated 97 lives in the 20 accidents.2
    When the likelihood of use of smoke hoods was included in the analysis for
    each accident, the total net benefit was estimated at 134 lives saved in
    the 20 accidents. The study also estimated that an additional 228 lives
    would have been saved in the 54 accidents where less data was available,
    assuming no delay in evacuation.3

    The U.S. Air Force and a major manufacturer are developing a drop-down
    smoke hood with oxygen. Because current oxygen masks in airplanes are not
    airtight around the mouth, they provide little protection from toxic gases
    and smoke in an in-flight fire. To provide protection from these hazards,
    as well as from decompression and postcrash fire and smoke, the Air
    Force's drop-down smoke hood with oxygen uses the airplane's existing
    oxygen system and can fit into the overhead bin of a commercial airliner
    where the oxygen mask is normally stowed. This smoke hood is intended to
    replace current oxygen masks but also be potentially separated from the
    oxygen source in a crash to provide time to evacuate.

    Status	Smoke hoods are currently available and produced by several
    manufacturers; however, not all smoke hoods filter carbon monoxide. They
    are in use on many military and private aircraft, as well as in buildings.
    An

    2These estimates assume 100 percent smoke hood use. The net 97 lives saved
    with a 15 second delay assumes that smoke hoods would have saved lives in
    six accidents and cost lives in four; the net 145 lives saved with a 10
    percent reduction in the evacuation rate assumes that smoke hoods would
    have saved lives in six accidents and cost lives in two.

    3 "Smoke Hoods: Net Safety Benefit Analysis," a collaborative effort by
    the Civil Aviation Authority, Federal Aviation Administration, Direction
    Generale de l'Aviation Civile, and Transport Canada, London, November
    1987, CAA Paper 87017.

    Appendix VI
    Summaries of Potential Improved Evacuation
    Safety Advancements

    individually-purchased filter smoke hood costs about $70 or more, but
    according to one manufacturer bulk order costs have declined to about $40
    per hood. In addition, they estimated that hoods cost about $2 a year to
    install and $5 a year to maintain. They weigh about a pound or less and
    have to be replaced about every 5 years. Furthermore, airlines could incur
    additional replacement costs due to theft if smoke hoods were placed near
    passenger seats in commercial aircraft.

    Neither the British CAA, the FAA, the DGAC, nor Transport Canada Civil
    Aviation has chosen to require smoke hoods. The British Air Accident
    Investigations Branch recommended that smoke hoods be considered for
    aircraft after the 1985 Manchester accident, in which 48 of 55 passengers
    died on a runway from an engine fire before takeoff, mainly from smoke
    inhalation and the effects of hydrogen cyanide. Additionally, a U.K.
    parliamentary committee recommended research into smoke hoods in 1999, and
    the European Transport Safety Council, an international nongovernmental
    organization whose mission is to provide impartial advice on
    transportation safety to the European Commission and Parliaments,
    recommended in 1997 that smoke hoods be provided in all commercial
    aircraft. Canada's Transportation Safety Board has taken no official
    position on smoke hoods, but has noted a deficiency in cabin safety in
    this area and recommended further evaluation of voluntary passenger use.

    Although smoke hoods are currently available, they remain controversial.
    Passengers are allowed to bring filter type smoke hoods on an airplane,
    but FAA is not considering requiring airlines to provide smoke hoods for
    passengers. The debate over whether smoke hoods should be installed in
    aircraft revolves mainly around regulatory concerns that passengers will
    not be able to put smoke hoods on quickly in an emergency; that hoods
    might hinder visibility, and that any delay in putting on smoke hoods
    would slow down an evacuation. FAA's and CAA's evacuation experiments-to
    determine how long it takes for passengers to unpack and don smoke hoods
    and whether an evacuation would be slowed by their use-have reached
    opposite conclusions about the effects of smoke hoods on evacuation rates.
    The CAA has noted that delays in putting on smoke hoods by only one or two
    people could jeopardize the whole evacuation. An opposite view by some
    experts is that the gas and smoke-induced incapacitation of one or two
    passengers could also delay an evacuation.

    FAA believes that an evacuation might be hampered by passengers' inability
    to quickly and effectively access and don smoke hoods, by

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    competitive passenger behavior, and by a lack of passenger attentiveness
    during pre-flight safety briefings. FAA noted that smoke hoods can be
    difficult to access and use even by trained individuals. However, other
    experts have noted that smoke hoods might reduce panic and help make
    evacuations more orderly, that competitive behavior already occurs in
    seeking access to exits in a fire, and that passengers could learn smoke
    hood safety procedures in the pre-flight safety briefings in the same way
    they learn to use drop-down oxygen masks or flotation devices.

    The usefulness of smoke hoods varies across fire scenarios depending on
    assumptions about how fast hoods could be put on and how much time would
    be available to evacuate. One expert told us that the time needed to put
    on a smoke hood might not be important in several fire scenarios, such as
    an in-flight fire in which passengers are seeking temporary protection
    from smoke until the airplane lands and an evacuation can begin. In other
    scenarios-a ground evacuation or postcrash evacuation - some experts argue
    that passengers in back rows or far from an exit may have their exit path
    temporarily blocked as other passengers exit and, because of the delay in
    their evacuation, may have a greater need and more time available to don
    smoke hoods than passengers seated near usable exits.

                                   Exit Slide Testing

    Background	Exit slide systems are rarely used during their operational
    life span. However, when such a system is used, it may be under adverse
    crash conditions that make it important for the system to work as
    designed. To prevent injury to passengers and crew escaping through
    floor-level exits located more than 6 feet above the ground, assist
    devices (i.e., slides or slide-raft systems) are used. (See fig. 15.)

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    The rapid deployment, inflation, and stability of evacuation slides are
    important to the effectiveness of an aircraft's evacuation system, as was
    illustrated in the fatal ground collision of a Northwest Airlines DC-9 and
    a Northwest Airlines 727 in Romulus, Michigan, in December 1990. As a
    result of the collision, the DC-9 caught fire, but there were several
    slide problems that slowed the evacuation. For example, NTSB later found
    that the internal tailcone exit release handle was broken, thereby
    preventing the tailcone from releasing and the slide from deploying.

    Because of concerns about the operability of exit slides, NTSB recommended
    in 1974 that FAA improve its maintenance checks of exit slide operations.
    In 1983, FAA revised its exit slide requirements to specify criteria for
    resistance to water penetration and absorption, puncture strength, radiant
    heat resistance, and deployment as flotation platforms after ditching.

    Status	All U.S. air carriers have an FAA-approved maintenance program for
    each type of airplane that they operate. These programs require that the
    components of an airplane's emergency evacuation system, which includes
    the exit slides, be periodically inspected and serviced. An FAA principal
    maintenance inspector approves the air carrier's maintenance program.
    According to NTSB, although most air carriers' maintenance programs
    require that a percentage of emergency evacuation slides or slide rafts be
    tested for deployment, the percentage of required on-airplane deployments
    is generally very small. For example, NTSB found that American Airlines'
    FAA-approved maintenance program for the A300 requires an on-airplane

    Appendix VI
    Summaries of Potential Improved Evacuation
    Safety Advancements

    operational check of four slides or slide rafts per year. Delta Air Lines'
    FAA-approved maintenance program for the L-1011 requires that Delta
    activate a full set of emergency exits and evacuation slides or slide
    rafts every 24 months. Under an FAA-approved waiver for its maintenance
    program, United is not required to deploy any slide on its 737 airplanes.

    NTSB also found that FAA allows American Airlines to include inadvertent
    and emergency evacuation deployments toward the accomplishment of its
    maintenance program; therefore, it is possible that American would not
    purposely deploy any slides or slide rafts on an A300 to comply with the
    deployment requirement during any given year. In addition, NTSB found that
    FAA also allows Delta Air Lines to include inadvertent and emergency
    evacuation deployments toward the accomplishment of its maintenance
    program.

    NTSB holds that because inadvertent and emergency deployments do not occur
    in a controlled environment, problems with, or failures in, the system may
    be more difficult to identify and record, and personnel qualified to
    detect such failures may not be present. For example, in an inadvertent or
    emergency slide or slide raft deployment, observations on the amount of
    time it takes to inflate the slide or slide raft, and the pressure level
    of the slide or slide raft are not likely to be documented. For these
    reasons, a 1999 NTSB report said that FAA's allowing these practices could
    potentially leave out significant details about the interaction of the
    slide or slide raft with the door or how well the crew follows its
    training mock-up procedures. Accordingly, in 1999, NTSB recommended that
    FAA stop allowing air carriers to count inadvertent and emergency
    deployments toward meeting their maintenance program requirement because
    conditions are not controlled and important information (on, for example,
    the interface between the airplane and the evacuation slide system,
    timing, durability, and stability) is not collected. The recommendation
    continues to be open at the NTSB. NTSB officials said they would be
    meeting to discuss this recommendation with FAA in the near future.

    Additionally, NTSB recommended that FAA, for a 12-month period, require
    that all operators of transport-category aircraft demonstrate the
    on-airplane operation of all emergency evacuation systems (including the
    door-opening assist mechanisms and slide or slide raft deployment) on 10
    percent of each type of airplane (at least one airplane per type) in their
    fleets. NTSB said that these demonstrations should be conducted on an
    airplane in a controlled environment so that qualified personnel can
    properly evaluate the entire evacuation system. NTSB indicated that the

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    results of the demonstrations (including an explanation of the reasons for
    any failures) should be documented for each component of the system and
    should be reported to FAA.4

                                  Overwing Exit Doors

    Background	Prompted by a tragedy in which 57 of the 137 people on board a
    British Airtours B-737 were killed because passengers found exit doors
    difficult to access and operate, the British Civil Aviation Authority
    initiated a research program to explore changes to the design of the
    overwing exit (Type III) door.

    Trained crewmembers are expected to operate most of the emergency
    equipment on an airplane, including most floor-level exit doors. But
    overwing exit doors, termed "self-help exits," are expected to be and will
    primarily be opened by passengers without formal training.5 NTSB reported
    that even when flight attendants are responsible for opening the overwing
    exit doors, passengers are likely to make the first attempt to open the
    overwing exit hatches because the flight attendants are not physically
    located near the overwing exits.

    There are now two basic types of overwing exit doors-the "self-help" doors
    that are manually removed inward and then stowed and the newer "swing out"
    doors that open outward on a hinge.

    According to NTSB, passengers continue to have problems removing the
    inward-opening exit door and stowing it properly. The manner in which the
    overwing exit is opened and how and where the hatch should be stowed is
    not intuitively obvious to passengers, nor is it easily or consistently
    depicted graphically. NTSB recently recommended to FAA that Type III
    overwing exits on newly manufactured aircraft be easy and intuitive to

    4NTSB, Emergency Evacuation of Commercial Airplanes, 2001, [A-00-76]
    (Washington, D.C.:2000).

    5The overwing exit hatch can weigh as much as 65 pounds and be 20 inches
    wide and 36 inches high.

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    open and have automatic stowage out of the egress path.6 NTSB has
    indicated that the semiautomatic, fast-opening, Type III overwing exit
    hatch could give passengers additional evacuation time.

    Status	Over-wing exit doors that "swing out" on hinges rather than
    requiring manual removal are currently available. The European Joint
    Aviation Authorities (JAA) has approved the installation of these
    outward-opening hinged doors on new-production aircraft in Europe. In
    addition, Boeing has redesigned the overwing exit door for its
    next-generation 737 series. This redesigned, hinged door has pressurized
    springs so that it essentially pops up and outward, out of the way, once
    its lever is pulled. The exit door handle was also redesigned and tested
    to ensure that anyone could operate the door using either single or double
    handgrips. Approximately 200 people who were unfamiliar with the new
    design and had never operated an overwing exit tested the outward-opening
    exit door. These tests found that the average adult could operate the door
    in an emergency. The design eliminates the problem of where to stow the
    exit hatch because the door moves up and out of the egress route.

    While the new swing-out doors are available, it will take some time for
    them to be widely used. Because of structural difficulties and cost, the
    new doors are not being considered for the existing fleet. For
    new-production airplanes, their use is mixed because JAA requires them in
    Europe for some newer Boeing 737s, but FAA does not require them in the
    United States. However, FAA will allow their use. As a result, some
    airlines are including the new doors on their new aircraft, while others
    are not. For example, Southwest Airlines has the new doors on its Boeing
    737s. The extent to which other airlines and aircraft models will have the
    new doors installed remains to be seen and will likely depend on the cost
    of installation, the European market for the aircraft, and any additional
    costs to train flight attendants in its use.

    6NTSB, Emergency Evacuation of Commercial Airplanes, [A-00-76]
    (Washington, D.C., 2000).

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    Next Generation Evacuation Equipment and Procedures

    Background	Airbus, a leading aircraft manufacturer, has begun building a
    family of A380 aircraft, also called Large Transport Aircraft (see fig.
    16). Early versions of the A380, which is scheduled to begin flight tests
    in 2005 and enter commercial service in 2006, will have 482 to 524 seats.
    The A380-800 standard layout references 555 seats. Later larger
    configurations could accommodate up to 850 passengers. The A380 is
    designed to have 16 emergency doors and require 16 escape slides, compared
    with the 747, which requires 12. Later models of the A380 could have 18
    emergency exits and escape slides.

    Status	The advent of this type of Large Transport Aircraft is raising
    questions about how passengers will exit the aircraft in an emergency. The
    upper deck doorsill of the A380 will be approximately 30 feet above the
    ground, depending on the position (attitude) of the aircraft. According to
    an Airbus official responsible for exit slide design and operations,
    evacuation slides have to reach the ground at a safe angle even if the
    aircraft is tipped up; however, extra slide length is undesirable if the
    sill height is normal.

    Appendix VI
    Summaries of Potential Improved Evacuation
    Safety Advancements

    Previously, regulations would have required slides only to touch the
    ground in the tip-up case, even if that meant introduction of relatively
    steep sliding surfaces. However, because of the sill height, passengers
    may hesitate before jumping and their hesitation may extend the total
    evacuation time. Because some passengers may be reluctant to leap onto the
    slide when they can see how far it is to the ground, the design concept of
    the A380 evacuation slides includes blinder walls at the exit and a curve
    in the slide to mask the distance to the ground.

    A next-generation evacuation system developed by Airbus and Goodrich
    called the "intelligent slide" is a possible solution to the problem of
    the Large Transport Aircraft's slide length. The technology is not a part
    of the slide, but is connected to the slide through what is called a door
    management system composed of sensors. The "brains" of the technology will
    be located inside the forward exit door of the cabin, and the technology
    is designed to adjust the length of the slide according to the fuselage's
    tipping angle to the ground. The longest upper-deck slide for an A380
    could exceed 50 feet.

    The A380 slides are made of a nylon-based fabric that is coated with
    urethane or neoprene, and they are 10 percent lighter than most other
    slides on the market. They have to be packed tightly into small bundles at
    the foot of emergency exit doors and are required to be fully inflated in
    6 seconds. Officials at Airbus noted that the slides are designed to
    withstand the radiant heat of a postimpact fire for 180 seconds, compared
    with the 90 seconds required by regulators.

    According to a Goodrich official, FAA will require Goodrich to conduct
    between 2,000 and 2,500 tests on the A380 slides to make sure they can
    accommodate a large number of passengers quickly and withstand wind, rain,
    and other weather conditions. The upper-level slides, which are wide
    enough for two people, have to enable the evacuation of 140 people per
    minute, according to Airbus officials. An issue to be resolved is whether
    a full-scale demonstration test will be required or whether a partial test
    using a certain number of passengers, supplemented by a computer
    simulation of an evacuation of 555 passengers, can effectively demonstrate
    an evacuation from this type of aircraft. Airbus officials told us that a
    full-scale demonstration could result in undesirable injuries to the
    participants and is therefore not the preferred choice.

    Officials at the Association of Flight Attendants have expressed concern
    that there has not been a full-scale evacuation demonstration involving
    the

                                      Appendix VI
                       Summaries of Potential Improved Evacuation
                                  Safety Advancements

    A380. They are concerned that computer modeling might not really match the
    human experience of jumping onto a slide from that height. In addition,
    they are concerned that other systems involved in emergency exiting, such
    as the communication systems, need to be tested under controlled
    conditions. As a result, they believe a full-scale demonstration under the
    current 90-second standard is necessary.

    Personal Flotation Devices

    Background	All commercial aircraft that fly over water more than 50
    nautical miles from the nearest shore are required to be equipped with
    flotation devices for each occupant of the airplane. According to FAA, 44
    of the 50 busiest U.S. airports are located within 5 miles of a
    significant body of water. In addition, life vests, seat cushions, life
    rafts, and exit slides may be used as flotation devices for water
    emergencies.

    FAA policies dictate that if personal flotation devices are installed
    beneath the passenger seats of an aircraft, the devices must be easily
    retrievable. Determinations of compliance with this requirement are based
    on the judgment of FAA as the certifying authority.

    Status	FAA is conducting research and testing on the location and types of
    flotation devices used in aircraft. When it has completed this work, it is
    likely to provide additional guidance to ensure that the devices are
    easily retrievable and usable. FAA's research is designed to analyze human
    performance factors, such as how much time passengers need to retrieve
    their vests, whether and how the cabin environment physically interferes
    with their efforts, and how physically capable passengers are of reaching
    their vests while seated and belted. FAA is reviewing four different life
    vest installation methods and has conducted tests on 137 human subjects.
    According to an early analysis of the data, certain physical installation
    features significantly affect both the ability of a typical passenger to
    retrieve an underseat life vest and the ease of retrieval. This work may
    lead to additonal guidance on the location of personal flotation devices.

    Appendix VI
    Summaries of Potential Improved Evacuation
    Safety Advancements

    FAA's research may also indicate a need for additional guidance on the use
    of personal flotation devices. In a 1998 report on ditching aircraft and
    water survival, FAA found that airlines differed in their instructions to
    passengers on how to use personal flotation devices.7 For example, some
    airlines advise that passengers hold the cushions in front of their
    bodies, rest their chins on the cushions, wrap their arms around the
    cushions with their hands grasping the outside loops, and float vertically
    in the water. Other airlines suggest that passengers lie forward on the
    cushions, grasp and hold the loops beneath them, and float horizontally.
    FAA also reported that airlines' flight attendant training programs
    differed in their instructions on how to don life vests and when to
    inflate them.

    7LB & M Associates, Inc., and Garnet A. McLean, Analysis of Ditching and
    Water Survival Training Programs of Major Airframe Manufacturers and
    Airlines, CAMI [DOT/FAA/AM-98/19], (Washington, D.C.).

    Appendix VII

    Summaries of General Cabin Occupant Safety and Health Advancements

    This appendix presents information on the background and status of
    potential advancements in general cabin occupant safety and health that we
    identified, including the following:

    o  advanced warnings of turbulence;

    o  preparations for in-flight medical emergencies;

    o 	reductions in health risks to passengers with certain medical
    conditions, including deep vein thrombosis; and

    o  improved awareness of radiation exposure.

    This appendix also discusses occupational safety and health standards for
    the flight attendant workforce.

    Advanced Warnings of Turbulence

    Background 	According to FAA, the leading cause of in-flight injuries for
    cabin occupants is turbulence. In June 1995, following two serious events
    involving turbulence, FAA issued a public advisory to airlines urging the
    use of seat belts at all times when passengers are seated, but concluded
    that the existing rules did not require strengthening. In May 2000, FAA
    instituted a public awareness campaign, called Turbulence Happens, to
    stress the importance of wearing safety belts to the flying public.

    Because of the potential for injury from unexpected turbulence, ongoing
    research is attempting to find ways to better identify areas of turbulence
    so that pilots can take corrective action to avoid it. In addition, FAA's
    July 2003 draft strategic plan targets a 33 percent reduction in the
    number of turbulence injuries to cabin occupants by 2008-from an annual
    average of 15 injuries per year for fiscal years 2000 through 2002 to no
    more than 10 injuries per year.

    Status	FAA is currently evaluating new airborne weather radar and other
    technologies to improve the timeliness of warnings to passengers and
    flight

                                      Appendix VII
                       Summaries of General Cabin OccupantSafety
                                and Health Advancements

    attendants about impending turbulence. For example, the Turbulence Product
    Development Team, within FAA's Aviation Weather Research Program, has
    developed a system to measure turbulence and downlink the information in
    real time from commercial air carriers. The International Civil Aviation
    Organization has approved this system as an international standard.
    Ongoing research includes (1) detecting turbulence in flight and reporting
    its intensity to augment pilots' reports, (2) detecting turbulence
    remotely from the ground or in the air using radar, (3) detecting
    turbulence remotely using LIDAR1 or the Global Positioning System's
    constellation of satellites, and (4) forecasting the likelihood of
    turbulence over the continental United States during the next 12 hours.
    Prototypes of the in-flight detection system have been installed on 100
    737-300s operated by United Airlines, and two other domestic air carriers
    have expressed an interest in using the prototype. FAA also plans to
    improve (1) training on standard operating procedures to reduce injuries
    from turbulence, (2) the dissemination of pilots' reports of turbulence,
    and (3) the timeliness of weather forecasts to identify turbulent areas.
    Furthermore, FAA encourages and some airlines require passengers to keep
    their seatbelts fastened when seated to help avoid injuries from
    unexpected turbulence.

    Currently, pilots rely primarily on other pilots to report when and where
    (e.g., specific altitudes and routes) they have encountered turbulent
    conditions en route to their destinations; however, these reports do not
    accurately identify the location, time, and intensity of the turbulence.
    Further research and testing will be required to develop technology to
    accurately identify turbulence and to make the technology affordable to
    the airlines, which would ultimately bear the cost of upgrading their
    aircraft fleets.

    Preparations for In-flight Medical Emergencies

    1LIDAR (LIght Detection And Ranging) is a technology that can measure the
    distance, speed, rotation, and chemical composition and concentration of a
    remote target, such as turbulence.

                                      Appendix VII
                       Summaries of General Cabin OccupantSafety
                                and Health Advancements

    Background	The Aviation Medical Assistance Act of 1998 directed FAA to
    determine whether the current minimum requirements for air carriers'
    emergency medical equipment and crewmember emergency medical training
    should be modified. In accordance with the act, FAA collected data for a
    year on in-flight deaths and near deaths and concluded that enhancements
    to medical kits and a requirement for airlines to carry automatic external
    defibrillators were warranted. Specifically, the agency found that these
    improvements would allow cabin crewmembers to deal with a broader range of
    in-flight emergencies.

    Status	On April 12, 2001, FAA issued a final rule requiring air carriers
    to equip their aircraft with enhanced emergency medical kits and automatic
    external defibrillators by May 12, 2004. Most U.S. airlines have installed
    this equipment in advance of the deadline.

    In the future, new larger aircraft may require additional improvements to
    meet passengers' medical needs. For example, new large transport aircraft,
    such as the Airbus A-380, will have the capacity to carry about 555 people
    on long-distance flights. Some aviation safety experts are concerned that
    with the large number of passengers on these aircraft, the number of
    in-flight medical emergencies will increase and additional precautions for
    in-flight medical emergencies (e.g., dedicating an area for passengers who
    experience medical emergencies in flight) should be considered. Airbus has
    proposed a medical room in the cabin of its A-380 as an option for its
    customers.

    Reducing Health Risks to Passengers with Certain Medical Conditions

    Background	Passengers with certain medical conditions (e.g., heart and
    lung diseases) can be at higher risk of health-related complications from
    air travel than the general population. For example, passengers who have
    limited heart or lung function or have recently had surgery or a leg
    injury can be at greater risk of developing a condition known as deep vein
    thrombosis (DVT) or

                                      Appendix VII
                       Summaries of General Cabin OccupantSafety
                                and Health Advancements

    travelers' thrombosis, in which blood clots can develop in the deep veins
    of the legs from extended periods of inactivity. Air travel has not been
    linked definitively to the development of DVT, but remaining seated for
    extended periods of time, whether in one's home or on a long-distance
    flight, can cause blood to pool in the legs and increase the chances of
    developing DVT. In a small percentage of cases, the clots can break free
    and travel to the lungs, with fatal results.

    In addition, the reduced levels of oxygen available to passengers
    in-flight can have detrimental health effects on passengers with heart,
    circulatory, and respiratory disorders because lower levels of oxygen in
    the air produce lower levels of oxygen in the body-a condition known as
    hypoxia. Furthermore, changes in cabin pressure (primarily when the
    aircraft ascends and descends) can negatively affect ear, nose, and throat
    conditions and pose problems for those flying after certain types of
    surgery (e.g., abdominal, cardiac, and eye surgery).

    Status 	Information on the potential effects of air travel on passengers
    with certain medical conditions is available; however, additional
    research, such as on the potential relationship between DVT and air
    travel, is ongoing. The National Research Council, in a 2001 report on
    airliner cabin air quality, recommended, among other things, that FAA
    increase efforts to provide information on health issues related to air
    travel to crewmembers, passengers, and health professionals. According to
    FAA's Federal Air Surgeon, since this recommendation was received, the
    agency has redoubled its efforts to make information and recommendations
    on air travel and medical issues available through its Web site
    www.cami.jccbi.gov/aam-400/PassengerHandS.htm. This site also includes
    links to the Web sites of other organizations with safety and health
    information for air travelers, such as the Aerospace Medical Association,
    the American Family Physician (Medical Advice for Commercial Air
    Travelers), and the Sinus Care Center (Ears, Altitude, and Airplane
    Travel), and videos on safety and health issues for pilots and air
    travelers. The Aerospace Medical Association's Web site,
    http://www.asma.org/publication.html, includes guidance for physicians to
    use in advising passengers about the potential risks of flying based on
    their medical conditions, as well as information for passengers to use in
    determining whether air travel is advisable given their medical
    conditions. Furthermore, some airlines currently encourage passengers to
    do exercises while seated, to get up and walk around during long flights,
    or to do both to improve blood circulation; however, walking around the
    airplane can also

                                      Appendix VII
                       Summaries of General Cabin OccupantSafety
                                and Health Advancements

    put passengers at risk of injuries from unexpected turbulence. In
    addition, a prototype of a seat has been designed with imbedded sensors,
    which record the movement of a passenger and send this information to the
    cabin crew for monitoring. The crew would then be able to track passengers
    seated for a long time and could suggest that these passengers exercise in
    their seats or walk in the cabin aisles to enhance circulation.

    While FAA's Web site on passenger and pilot safety and health provides
    links to related Web sites and videos (e.g., cabin occupant safety and
    health issues), historically, the agency has not tracked who uses its Web
    site or how frequently it is used to monitor the traveling public's
    awareness and use of this site. Agency officials told us that they plan to
    install a counter capability on its Civil Aerospace Medical Institute Web
    site by the end of August 2003 to track the number of visits to its
    aircrew and passenger health and safety Web site. The World Health
    Organization has initiated a study to help determine if a linkage exists
    between DVT and air travel. Further, FAA developed a brochure on DVT that
    has been distributed to aviation medical examiners and cited in the
    Federal Air Surgeon's Bulletin. The brochure is aimed at passengers rather
    than airlines and suggests exercises that can be done to promote
    circulation.

    Improved Awareness of Radiation Exposure

    Background	Pilots, flight attendants, and passengers who fly frequently
    are exposed to cosmic radiation at higher levels (on a cumulative basis)
    than the average airline passenger and the general public living at or
    near sea level. This is because they routinely fly at high altitudes,
    which places them closer to outer space, which is the primary source of
    this radiation. High levels of radiation have been linked to an increased
    risk of cancer and potential harm to fetuses. The amount of radiation that
    flight attendants and frequent fliers are exposed to-referred to as the
    dose-depends on four primary factors: (1) the amount of time spent in
    flight; (2) the latitude of the flight- exposure increases at higher
    latitudes; for example, at the same altitude, radiation levels at the
    poles are about twice those at the equator; (3) the altitude of the
    flight-exposure is greater at high altitudes because the layer of
    protective atmosphere becomes thinner; and (4) solar activity- exposure is
    higher when solar activity increases, as it does every 11 years or so.
    Peak periods of solar activity, which can increase exposure to

                                      Appendix VII
                       Summaries of General Cabin OccupantSafety
                                and Health Advancements

    radiation by 10 to 20 times, are sometimes called solar storms or solar
    flares.

    Status	FAA's Web site currently makes available guidance on radiation
    exposure levels and risks for flight and cabin crewmembers, as well as a
    system for calculating radiation doses from flying specific routes and
    specific altitudes. To increase crewmembers' awareness of in-flight
    radiation exposure, FAA issued two Advisory Circulars for crewmembers. The
    first Advisory Circular, issued in 1990, provided information on (1)
    cosmic radiation and air shipments of radioactive material as sources of
    radiation exposure during air travel; (2) guidelines for exposure to
    radiation; (3) estimates of the amounts of radiation received on air
    carriers' flights on various routes to and from, or within, the contiguous
    United States; and (4) examples of calculations for estimating health
    risks from exposure to radiation. The second Advisory Circular, issued in
    1994, recommended training for crewmembers to inform them about in-flight
    radiation exposure and known associated health risks and to assist them in
    making informed decisions about their work on commercial air carriers. The
    circular provided a possible outline of courses, but left it to air
    carriers to gather the subject matter materials. To facilitate the
    monitoring of radiation exposure levels by airliner crewmembers and the
    public (e.g., frequent fliers), FAA has developed a computer model, which
    is publicly available via the agency's Web site. This Web site also
    provides guidance and recommendations on limiting radiation exposure.
    However, it is unclear to what extent flight attendants, flight crews, and
    frequent fliers are aware of and use FAA's Web site to track the radiation
    exposure levels they accrue from flying. Agency officials told us that
    they plan to install a counter capability its Civil Aerospace Medical
    Institute Web site by the end of August 2003, to track the number of
    visits to its aircrew and passenger health and safety Web site. FAA also
    plans to issue an Advisory Circular by early next year, which incorporates
    the findings of a just completed FAA report, "What Aircrews Should Know
    About Their Occupational Exposure to Ionizing Radiation." This Advisory
    Circular will include recommended actions for aircrew and information on
    solar flare event notification of aircrew. While FAA provides guidance and
    recommendations on limiting the levels of cosmic radiation that flight
    attendants and pilots are exposed to, it has not developed any
    regulations.

    In contrast, the European Union issued a directive for workers in May
    1996, including air carrier crewmembers (cabin and flight crews) and the
    general public, on basic safety and health protections against dangers
    arising from

                                      Appendix VII
                       Summaries of General Cabin OccupantSafety
                                and Health Advancements

    ionizing radiation. This directive set dose limits and required air
    carriers to (1) assess and monitor the exposure of all crewmembers to
    avoid exceeding exposure limits, (2) work with those individuals at risk
    of high exposure levels to adjust their work or flight schedules to reduce
    those levels, and (3) inform crewmembers of the health risks that their
    work involves from exposure to radiation. It also required airlines to
    work with female crewmembers, when they announce a pregnancy, to avoid
    exposing the fetus to harmful levels of radiation. This directive was
    binding for all European Union member states and became effective in May
    2000. According to European safety officials, pregnant crewmembers are
    often given the option of an alternative job with the airline on the
    ground to avoid radiation exposure to their fetuses. Furthermore, when
    flight attendants and pilots reach recommended exposure limits, European
    air carriers work with crewmembers to limits or change their subsequent
    flights and destinations to minimize exposure levels for the balance of
    the year. Some air carriers ground crewmembers when they reach annual
    exposure limits or change their subsequent flights and destinations to
    minimize exposure levels for the balance of the year.

    Occupational Safety and Health Standards for Flight Attendants

    Background	In 1975, FAA assumed responsibility from the Occupational
    Health and Safety Administration (OSHA) for establishing safety and health
    standards for flight attendants. However, FAA has only recently begun to
    take action to provide this workforce with OSHA-like protections. For
    example, in August 2000, FAA and OSHA entered into a memorandum of
    understanding and issued a joint report in December 2000, which identified
    safety and health concerns for the flight attendant workforce and the
    extent to which OSHA-type standards could be used without compromising
    aviation safety. On September 29, 2001, the DOT Office of the Inspector
    General (DOT IG) reported that FAA had made little progress toward
    providing flight attendants with workplace protections and urged FAA to
    address the recommendations in the December 2000 report and move forward
    with setting safety and health standards for the flight attendant
    workforce. In April 2002, the DOT IG reported that FAA and OSHA had made
    no progress since it issued its report in September 2001. According to FAA
    officials, the

                                      Appendix VII
                       Summaries of General Cabin OccupantSafety
                                and Health Advancements

    joint FAA and OSHA effort was put on hold because of other priorities that
    arose in response to the events of September 11, 2001.

    Status	FAA has not yet established occupational safety and health
    standards to protect the flight attendant workforce. FAA is conducting
    research and collecting data on flight attendants' injuries and illnesses.

    On March 4, 2003, FAA announced the creation of a voluntary program for
    air carriers, called the Aviation Safety and Health Partnership Program.
    Through this program, the agency intends to enter into partnership
    agreements with participating air carriers, which will, at a minimum, make
    data on their employees' injuries and illnesses available to FAA for
    collection and analysis. FAA will then establish an Aviation Safety and
    Health Program Aviation Rule-Making Committee to provide advice and
    recommendations to

    o 	develop the scope and core elements of the partnership program
    agreement;

    o  review and analyze the data on employees' injuries and illnesses;

    o 	identify the scope and extent of systematic trends in employees'
    injuries and illnesses;

    o 	recommend remedies to FAA that use all current FAA protocols, including
    rule-making activities if warranted, to abate hazards to employees; and

    o 	create any other advisory and oversight functions that FAA deems
    necessary.

    FAA plans to select members to provide a balance of viewpoints, interests,
    and expertise. The program preserves FAA's complete and exclusive
    responsibility for determining whether proposed abatements of safety and
    health hazards would compromise or negatively affect aviation safety.

    FAA is also funding research through the National Institute for
    Occupational Safety and Health (NIOSH) to, among other things, determine
    the effects of flying on the reproductive health of flight attendants,
    much of

    Appendix VII
    Summaries of General Cabin OccupantSafety
    and Health Advancements

    which has been completed.2 FAA plans to monitor cabin air quality on a
    selected number of flights, which will help it set standards for the
    flight attendant workforce.

    The Association of Flight Attendants has collected a large body of data on
    flight attendants' injuries and illnesses, which it considers sufficient
    for use in establishing safety and health standards for its workforce.
    Officials from the association do not believe that FAA needs to collect
    additional data before starting the standard-setting process.

    The European Union has occupational safety and health standards in place
    to protect flight attendants, including standards for monitoring their
    levels of radiation exposure. An official from an international
    association of flight attendants told us that while flight attendants in
    Europe have concerns similar to those of flight attendants in the United
    States (e.g., concerns about air quality in airliner cabins), the European
    Union places a heavier emphasis on worker safety and health, including
    safety and health protections for flight attendants.

    2NIOSH is also conducting research on airliner cabin environmental
    quality, respiratory symptoms of flight attendants, and disease
    transmission.

    Appendix VIII

    Application of a Cost Analysis Methodology to Inflatable Lap Belts

    The following illustrates how a cost analysis might be conducted on each
    of the potential advancements discussed in this report. Costs estimated
    through this analysis could then be weighed against the potential lives
    saved and injuries avoided from implementing the advancements. This
    methodology would allow advancements to be compared using comparable cost
    data that when combined with similar analyses of effectiveness to help
    decisionmakers determine which advancements would be most effective in
    saving lives and avoiding injuries, taking into account their costs. The
    methodology provides for developing a cost estimate despite significant
    uncertainties by making use of historical data (e.g, historical variations
    in fuel prices) and best engineering judgments (e.g., how much weight an
    advancement will add and how much it will cost to install, operate, and
    maintain). The methodology formally takes into account the major sources
    of uncertainty and from that information develops a range of cost
    estimates, including a most likely cost estimate. Through a common
    approach for analyzing costs, the methodology facilitates the development
    of comparable estimates. This methodology can be applied to advancements
    in various stages of development.

    Inflatable Lap Belts	Inflatable lap belts are designed to protect
    passengers from a fatal impact with the interior of the airplane, the most
    common cause of death in survivable accidents. Inflatable seat belts adapt
    advanced automobile technology to airplane seats in the form of seat belts
    with air bags embedded in them. Several hundred of these seatbelt airbags
    have been installed in commercial airliners in bulkhead rows.

    Summary of Results	We calculated that requiring these belts on an
    average-sized airplane in the U.S. passenger fleet would be likely to cost
    from $98,000 to $198,000 and to average about $140,000 over the life of
    the airplane. On an annual basis, the cost would be likely to range from
    $8,000 to $17,000 and to average $12,000.

    We considered several factors to explain this range of possible costs. The
    installation price of these belts is subject to uncertainty because of
    their limited production to date. In addition, these belts add weight to
    an aircraft, resulting in additional fuel costs. Fuel costs depend on the
    price of jet fuel and on how many hours the average airplane operates,
    both subject to uncertainty. Table 5 lists the results of our cost
    analysis for an average-sized airplane in the U.S. fleet.

                                     Appendix VIII
                       Application of a Cost Analysis Methodology
                                to Inflatable Lap Belts

        Table 4: Costs to Equip an Average-sized Airplane in the U.S. Fleet with
    Inflatable Lap Seat Belts, Estimated under Alternative Scenarios (In 2002
                           discounted dollars) Cost scenario

                        Cost        Low   Average          High    95 percentilea
                  Life-cycle  $98,000    $140,000      $198,000          $186,000
                  Annualized   $8,000     $12,000       $17,000           $16,000
                 Per ticketb      $0.08    $0.13          $0.19             $0.18

    Source: GAO analysis.

    aFor example, a 95 percentile estimate means that there is a 95 percent
    probability that the total life-cycle costs per airplane will be $186,000
    or less.

    bCost rounded to the nearest cent.

    According to our analysis, the life-cycle and annualized cost estimates in
    table 5 are influenced most by variations in jet fuel prices, followed by
    the average number of hours flown per year and the installation price of
    the belts. The cost per ticket is influenced most by variations in jet
    fuel prices, followed by the average number of hours flown per year, the
    number of aircraft in the U.S. fleet, and the number of passenger tickets
    issued.

    Methodology	To analyze the cost of inflatable lap belts, we collected data
    on key cost variables from a variety of sources. Information on the belts'
    installation price, annual maintenance and refurbishment costs, and added
    weight was obtained from belt manufacturers. Historical information on jet
    fuel prices, extra gallons of jet fuel consumed by a heavier airplane,
    average hours flown per year, average number of seats per airplane, number
    of airplanes in the U.S. fleet, and number of passenger tickets issued per
    year was obtained from FAA and DOT's Office of Aviation Statistics.

    To account for variation in the values of these cost variables, we
    performed a Monte Carlo simulation.1 In this simulation, values were
    randomly drawn 10,000 times from probability distributions characterizing
    possible values

    1"Monte Carlo simulation is a widely used computational method for
    generating probability distributions of variables that depend on other
    variables or parameters represented as probability distributions. Monte
    Carlo methods are to be contrasted with the deterministic methods used to
    generate specific single number or point estimates." Susan Poulter, "Monte
    Carlo Simulation in Environmental Risk Assessment - Science, Policy And
    Legal Issues," 9 Risk: Health, Safety & Environment 7 [Winter 1998].

                                     Appendix VIII
                       Application of a Cost Analysis Methodology
                                to Inflatable Lap Belts

    for the number of seat belts per airplane, seat belt installation price,
    jet fuel price, number of passenger tickets, number of airplanes, and
    hours flown.2 This simulation resulted in forecasts of the life-cycle cost
    per airplane, the annualized cost per airplane, and the cost per ticket.

    Major assumptions in the cost analysis are described by probability
    distributions selected for these cost variables. For jet fuel prices,
    average number of hours flown per year, and average number of seats per
    airplane, historical data were matched against possible probability
    distributions.3 Mathematical tests were performed to find the best fit
    between each probability distribution and the data set's distribution. For
    the installation price, number of passenger tickets, and number of
    airplanes, less information was available.4 For these variables, we
    selected probability distributions that are widely used by researchers.
    Table 6 lists the type of probability distribution and the relevant
    parameters of each distribution for the cost variables.

                                Table 5: Key Assumptions

                   Type of    Mean or Standard
        Cost     distribution average deviation Minimum Maximum Likeliest Mode  Scale
      variable
     Fuel price   lognormal     $0.93     $0.33
    Seats      lognormal       161         8
    Installation  triangular                       $300    $600   $450
    price
    Hours       extreme      2,353                                     2,643   539
                    value
     Airplanes      normal      4,438       399
      Tickets       normal        419        35

    Source: GAO analysis.

    2A probability distribution is a set of all possible events and their
    associated probabilities. Probability refers to the likelihood of an
    event.

    3Historical data from 1975 through 2001 were available for the number of
    seats per plane, and from 1977 through 2002 for jet fuel prices. Aircraft
    utilization data for 2001 were available for annual hours per aircraft.

    4Historical data from 1995 through 2001 were available for the number of
    planes and tickets.

    Appendix IX

                         GAO Contacts and Staff Acknowledgments

    GAO Contacts	Gerald L. Dillingham (202) 512-2834 Glen Trochelman (202)
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    Staff 	In addition to those named above, Chuck Bausell, Helen Chung,
    Elizabeth Eisenstadt, David Ehrlich, Bert Japikse, Sarah Lynch, Sara Ann

    Acknowledgments Moessbauer, and Anthony Patterson made key contributions
    to this report.

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