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Statement of Need: There have been a number of fires in the cargo or baggage compartments of transport category airplanes in recent years. Some of which have resulted in accidents and loss of life. Although the FAA has already taken action to improve the safety of these compartments by improving the fire-resistance of liners, the continuing occurrence of fires and the seriousness of the consequences of an uncontrolled fire have resulted in a review of the entire cargo compartment classification system.

Summary of the Legal Basis: 49 USC 106(g) empowers the Administrator to prescribe regulations and minimum standards in the interest of safety for aircraft and equipment.

Alternatives: The FAA considered the possibility of requiring only the installation of detection systems. Having a detection system would enable the flight crew to abort a takeoff if an ignition occurred during the brief period before the airplane became airborne. If, on the other hand, the fire occurred after the airplane became airborne, which is more likely, the fire could burn out of control before a safe landing could be made. Since the installation of detection systems alone would provide only a small incremental increase in safety, it is essential that both detection and suppression systems be provided for these compartments. ^POther alternatives include use of suppression agents other than halogenated hydrocarbon (halon) and use of a waterspray system. The FAA has participated in an extensive program to develop criteria on which to evaluate possible alternatives. Objectives of this international program, with active participation by the aviation industry and other regulatory authorities, include research and development of alternative agents and systems. The FAA has accelerated development of criteria for certification of alternatives and is committed to expeditious review and certification of alternatives as they are developed.

Anticipated Costs and Benefits: The rule would allow three years for compliance. Therefore, airplanes that are expected to be permanently retired from service on or before December 31, 2001, are omitted from the analysis (assuming the rule would become effective on January 1, 1998). The FAA estimates that total life-cycle costs for the retrofitted fleet in nominal terms are approximately $296 million or $194 million at present value. The expected reduction in the proportion of occupants fatally injured in an accident resulting from a fire occurring in a Class D compartment is estimated as the ratio of fatalities to total occupants. Of the 1,411 individuals involved in accidents discussed in the regulatory evaluation, 523 were fatally injured, representing approximately 37 percent of occupants. Applying a risk reduction estimate to airplane-specific departure, capacity, and load factor information, the FAA estimates that the rule would yield benefits of approximately $458 million over the life of the affected in-service fleet (or approximately $228 million at present value.)

Risks: At least 19 fires have occurred in Class D compartments over the past two decades. The consequences of those fires ranged from no airplane damage and no occupant injury to complete destruction of an airplane. The exception, insofar as injuries are concerned, was the fire that occurred in May of 1996 in the Class D compartment of a McDonnell Douglas DC-9 operated by ValueJet Airlines, which resulted in the destruction of the airplane with a loss of 110 lives. ^PAn additional potential hazard in the cargo or baggage compartments of passenger-carrying airplanes has resulted from passengers transporting aerosol cans in checked baggage. Tests show that these cans can burst if they are in a burning suitcase for more than two minutes. These tests further show that if the burst occurs in a non-inert atmosphere, such as that of a Class D compartment, there is an immediate auto-ignition of the propellant. If, on the other hand, the burst occurs in an inert atmosphere, such as that of a Class C compartment in which an extinguishing agent has been discharged, the propellant does not ignite and poses no further hazard. ^PImproved standards are needed to increase protection from possible in-flight fires.