Richard E. Lyon

The goal of the Federal Aviation Administration's Fire Research Program is to eliminate fire as a cause of death in aircraft accidents. The Fire Research Program is a long-range research effort which includes advanced materials in a systems approach to improved aircraft cabin fire safety along with fire prevention, detection, and control. The objective of the Advanced Fire-Safe Materials portion of the program is to discover the fundamental relationships between the composition and structure of materials and their behavior in fires to enable the design of a totally fire-resistant cabin for future commercial aircraft. Research will be basic in nature and will focus on synthesis, characterization, modeling, and processing of new materials and materials combinations to improve the fire performance, increase the functionality, and reduce the cost of next-generation cabin materials.

Richard Lyon

The fire response of a potassium aluminosilicate matrix (geopolymer) carbon fiber composite was measured and the results compared to organic matrix composites being used for infrastructure and transportation applications. At irradiance levels of 50 kW/m2, typical of the heat flux in a well developed fire, glass- or carbon-reinforced polyester, vinylester, epoxy, bismaleimde, cyanate ester, polyimide, phenolic, and engineering thermoplastic laminates ignited readily and released appreciable heat and smoke, while carbon-fiber reinforced geopolymer composites did not ignite, burn, or release any smoke even after extended heat flux exposure. The geopolymer matrix carbon fiber composite retains sixty-three percent of its original 245 MFa flexural strength after a simulated large fire exposure.

Louise C. Speitel

The development of a survival model for post-crash aircraft cabin fire is described in this paper. Its development is based on an extensive review of the literature on the toxicity of combustion gases and on thermal hazards. This model is to be used as a predictive tool to gauge human survivability in full scale aircraft cabin fire tests. The extensive literature search was conducted for carbon monoxide (CO), carbon dioxide (CO2), hydrogen cyanide (HCN), low oxygen, hydrogen fluoride (HF), hydrogen chloride (HCI), hydrogen bromide (HBr), nitrogen dioxide (NO2), sulfur dioxide (SO2), acrolein (CH2-CHCHO), and heat exposures. Those studies by various investigators of exposures to single and mixed gases on humans, primates rats and mice at different physical activity levels were compared. Regression equations were derived from those studies to give the best fit to gas exposure concentration and duration data. The equation judges to best model the human escaping from an aircraft cabin was selected for each gas. The survival model uses incapacitation data to obtain a fractional effective dose (FED) for incapacitation (FED1) and lethality data, inclusive of post exposure deaths, to obtain a FED for lethality (FED1). The exposure time required for either FED1 or FEDL to reach unity, using a projected set of gas concentrations, represent the exposure time available to escape from the specified fire environment or to survive post exposure, respectively. The effect of CO2 in increasing the uptake of other gases was factored into the concentration term in the FED equation for all gases with the exception of CO2 and oxygen. Higher respiratory minute volumes due to CO2 exposure were found to be important factor in predicting the time available to escape. This FED-based model can be applied to the evaluation of the toxicity of smoke in computer modeling of aircraft fire situations.

R. Tapscott, J.A. Brown, L.E. Dvorak, A. Gupta, J.W. Mossel, E. Jacobson, J. Gibson, K. Metchis, T. Simpson, L. Speitel, R.A. Tetla

This report contains summary of available fire suppression agents, their properties and applicability in the various aircraft applications. Classes of agents, with presently available agents listed, are recommended for use in the development of test protocols. The test protocol developed for a class of agents can be used, with minor modifications, to test all agents belonging to that class.

Vanessa J. Breechling, Floyd Spencer

This report details the validation analysis of PRI's Magneto-Optic/Eddy-Current Imager (MOl). The analysis includes both a reliability analysis of the system and an economic analysis of the potential benefits and costs related to its use.

The reliability analysis consisted of blind inspections of well characterized panels simulating a fuselage lap splice. The panels contained cracks of known sizes emanating from under rivet heads on the upper row of rivets. The MOl inspection times were less, on average, than were inspection times using a sliding probe. Twenty percent reduction in inspection times is consistent with the data obtained and is used as a baseline for the economic analysis.

The economic analysis considers the effects of individual factors that contribute to the cost effectiveness of the MOL The possible returns on the investment for a representative maintenance facility lare calculated using the net present value methodology. Specific characteristics are defined for the representative facility; and then they are varied to account for the differences in the. maintenance community.

For a facility which can take full advantage of the potential time and labor savings associated with implementation of the MOl, the investment in MOl would generate a positive return in less than one year. In this fully competitive scenario the cumulative net present value at the end of the tenth year would be over $160,000. Under a semi-competitive scenario, the not present value is negative throughout the life cycle of the investment.