Constantine P. Sarkos, Richard G. Hill, Timothy R. Marker

This paper describes a series of full-scale fire test to evaluate and optimize an on-board aircraft cabin water spray mist for passenger protection against postcrash fires. The initial system consisted of an array of nozzles at the ceiling, which continuously discharged water throughout the cabin for 3 minutes. Several fire scenarios were examined in both narrow-body and wide-body test articles. An analysis of the hazard measurements using a fractional effective dose model indicted the water spray provided significant improvements in survival time for all but the most severe scenario tested. Additionally, a zoned water sprat system was conceptualized, designed and tested under full-scale conditions in an attempt to reduce the weight penalty of water. Test results indicated that an optimal zoned system gives more protection and improved visibility than a continuous spray system with approximately 10 percent of the water. Tests were also conducted in a commuter test article to determine the relative effectiveness of a water spray system and improved fire resistant materials.

J.T. Leonard

The Total Ship Survivability/Fleet Training (TSS/FT) Model is designed to be a shipboard damage control training tool for Fleet personnel. The latest update to this model includes the development of a smoke “module” that estimates the generation and movement of smoke, resulting from fires caused by a specific weapon impact.

The smoke spread module of the TSS/FT Model incorporates several assumptions and simplifications that allowed for the development of basic equations and guideline used in describing the generation and movement of smoke. The rate of smoke production and the speed at which smoke spreads throughout a ship are a function of the model’s estimated flame spread rate. The primary input for the smoke movement module are the compartment “on fire” times generated by the model’s flame spread module.

The TSS/FT Model for the DDG-51 Class is the first to incorporate the smoke spread module. Smoke spread data (model output) for the hip class have been developed and reviewed with respect to “believability”, with favorable results.

D.E. Cagliostro, J.A. Parker

A physiochemical model is presented which predicts the air temperature and gas concentration changes expected to occur in a compartment of an aerospace vehicle as a result of an unwanted fire. The change in compartment air temperature can be predicted from the heat release rates of the burning materials and the net heat loss from the compartment. The changes in gas concentration ration within the compartment are predicted from the temperature-dependent chemical kinetics of the material pyrolysis and the net mass loss from the compartment. Exposure to gases and elevated temperatures generated by the fire produces life-threatening ill effects in humans. Parameters used to measure thermal effects were the time to reach and the duration of an average skin temperature of 45° C and a body enthalphy of 100-252 kcal representing a pain and metabolic threshold. The parameters used to measure toxic gas effects were the time to reach and the duration of time exposed to harmful levels of gas concentration. Synergistic effects of gas mixtures or of exposure to combined thermal effects and toxic gas and smoke are not considered in the analysis. The analysis was applied to the case of a small fire in the electronics area of an aero space vehicle. In this case a polyvinyl chloride electrical insulation decomposes generating HCl gas which is released into the compartment. A parametric study is made of skin temperature and body enthalpy as a function of heat release, ventilation rates, and physical stress levels. The results of the analysis showed that ventilation at relatively low rates could effectively reduce thermal and toxic gas effects while. stress could increase and prolong.

Constantine Sarkos, Richard Hill

Materials are available for preventing or retarding aircraft cabin fires involving urethane foam seat cushions. Realistic fire tests performed in a wide-body test article demonstrate that some in-flight and ramp fires can be prevented, and that the allowable time for safe evacuation can be significantly extended during a survivable post crash fuel fire, when the urethane foam seat cushion is covered by a "blocking layer" material.

Thomas L. Reynolds

The purpose of this paper is to discuss some of the research and development activities being conducted in the Boeing Commercial Airplane Group (BCAG) that re related to safety improvements in the passenger cabin of commercial jet aircraft.