F.A.A. Technical Center, Transport Canada Aviation and Joint Aviation Authorities

Cabin safety presents challenges common to all aviation authorities. Related issues and needed research must be accomplished through a totally integrated program.

To enhance their respective research capabilities, the U.S. Federal Aviation Administration (FAA) and the Transport Canada Aviation (TCA), the aviation authorities of North America, and the Joint Aviation Authorities (JAA), the aviation authority of Europe, have been doing in rulemaking, agreed to cooperate in research the transport category airplane cabin safety. The FAA/JAA/TCA Cabin Safety Research Program is the formalization of this agreement.

Specically, the goal of the Cabin Research Program is to provide a mechanism for the coordination of pertinent activities and, as appropriate, the conduct of cooperative joint, and complementry programs to the benefit of the three authorities.

For the purpose of this program, cabin safety is intended to address acute eventss/condition which can be dealt with by changes within (or closely associated with) the cabin. Although in-flight issues form an integral part of cabin safety, the primary focus is postcrash survivability the principal elements of which are structural crashworthiness, fire safety, evacuation and overwater survival.

The foremost decision-making tool to identify and access the potential of needed research (and of past improvements) are a probailistic risk analysis model and a cabin safety accident/incident information data bank/base.

William T. Westfield

A review of regulatory actions taken by the Federal Aviation Administration (FAA) over approximately the past thirty years was made to identify which of these actions were preceded by, or triggered by research and development (R&D) programs. The focus of this analysis was limited to those actions and R&D that pertained to aircraft safety. Research was frequently requested to be performed by the industry elements themselves, namely the engine and aircraft manufacturers, independent research organizations, or by academia. As the FAA experience with the operational fleets grew, some research was accomplished by the internal FAA and governmental organizations, such as the Civil Aeromedical Institute or the Technical Center, and the National Aeronautics and Space Administration.

The review revealed that the rulemaking actions were supported quite frequently by research. While it is true that major accidents brought the attention to technology unknowns, and the subsequent rulemaking to prevent the problem appeared to be moving too slowly to provide solutions to the need, the review showed many risks have been reduced, (cabin fires, inadvertent collision with terrain, faster evacuation, to name a few) through the performance of research.

Richard E. Lyon

This report is a compilation of papers presented at a special symposium on Fire Calorimetry held at NIST, Gaithersburg, MD, on July 27-28, 1995. It includes papers on the theory, instrumentation, and use of fire (or heat release) calorimetry in assessing the fire hazard of materials.

Louise C. Speitel

This report presents an extensive review of the literature on the toxic and thermal hazards relating to human survival in aircraft cabin fires. Studies by various authors of exposures to single and mixed gases on humans, primates, rats and mice are presented for different activity levels and a wide range of concentrations and temperatures. Regression equations giving the best fit were derived from these studies. The regression equation which was judged to best model the human escaping from an aircraft cabin fire was selected for each gas and utilized in the survival model. The effect of carbon dioxide increasing the uptake of other gases was included in the model.

This survival model uses incapacitation data to obtain a fractional effective dose for incapacitation (FEDI) and lethality data to obtain a fractional effective dose for lethality (FEDL). The time when either FED reaches 1 determines the exposure time available to escape from an aircraft cabin fire and to survive postexposure.

Constantine P. Sarkos

The Federal Aviation Administration (FAA) has conducted numerous full-scale fire tests for the purpose of characterizing the postcrash cabin fire environment and developing improved fire test criteria for cabin materials. The tests consistently demonstrated the importance of cabin flashover on occupant survivability. Flashover is basically a sudden, very rapid spread of fire, generating large quantities of heat, smoke and toxic gases that quickly fill the cabin. Before flashover the cabin environment is largely survivable; after flashover, occupant survival becomes highly unlikely. Thermal incapacitation is more important near the fire origin and at higher elevations; whereas, toxic gas incapacitation is predominant away from the fire origin and at lower elevations. The FAA has developed and adopted improved fire test methods for seat cushions (fire blocking layers0 and interior panels (low heat release). In both cases the fire test methods are consistent with full-scale test results and serve to improve occupant survivability by delaying the onset of flashover, which produces large quantities of toxic gases, providing substantially greater available time for occupant evacuation.