R.L. Alpert

The pressure modeling technique is used to study upward fire spread on fuel wall composed of char-forming or laminated mater'ials. Time-resolved measurements are obtained at one-atmosphere (full-scale) and at elevated air pressure (model scales) to characterize fire growth in terms of rate of total mass loss, flame height; upward flame spread rate, and maximum lateral flame dimensions during the spread process. The char-forming materials (pine-wood, particle-board and a rigid, polyurethane foam) are tested in a 90° wall-corner configuration while the laminated materials (PMMA in combination with PMMA or ceramic backings) are tested in a wall configuration. Thermally-thick PMMA is tested in both configurations for purposes of comparison. Results are generally consistent with the pressure modeling scheme and a series of one-dimensional, transient thermal conduction and pyrolysis calculations. The be Lhavior of the rigid polyurethane foam, however, is an exception. This material does not support self-sustained upward flame spread at one-atmosphere when exposed to flames from a 0.1 m high PMMA ignition source but does support rapid fire growth at elevated pressures. A possible reason for the anomalous polyurethane behavior is the intumescent structure of the hot char at one-atmosphere, but a better understanding of the mechanism of upward or wind-aided flame spread oQ chairing materials is needed to resolve the issue. It is concluded that additional measurements of upward flame spread rates on a variety of simplified, laminated materials will be necessary. It is also concluded that the pressure modeling technique may be valid for predicting fire growth on most charring fuels in corner configurations (with or without a ceiling) as long as a sufficiently large heat flux initiates self-sustained fire spread.

Thor I. Eklund

A perfect stirrer model was used to analyze the concentration decay of extinguisher agents in ventilated compartments. The exponential decay curves were integrated over time to yield dosages. In this way, extinguisher agent weights, compartment volumes, and ventilation rates were matched against allowable agent doses to yield selection nomographs for halon 1211, halon 1301, and carbon dioxide. The model predictions were compared with experimental data, and the concept of an effective air-change time was developed for practical application.

William R. Kirkham, S. Marlene Wicks, Donald Lee Lowrey

As the title implies, this is an illustrated commentary on crash survival in general aviation aircraft. Photographs, drawings, and discussion present some basic concepts of crash forces; mechanisms of injury to occupants; and the role of shoulder harnesses, lapbelts, and seats in attenuating crash forces. Findings in a number of accidents relate seats and restraints to the fate of the occupants.

This report is designed to inform the reader of the value of good restraints in crashes of general aviation aircraft. Also it will serve to orient Federal Aviation Administration (FAA) personnel and others to a set of projection slides that may be used wholly or in part in safety presentations to pilots and aviation. groups. The projection slides, duplicates of the photographs and. drawings in this report, are available from the Aeromedical Education Branch of the FAA Civil Aeromedical Institute.

W.J. Parker

The temperature, heat fluxes, air velocities, and times to flashover were compared between a number of previously reported full – and – reduced-scale room fire tests. The model tests were usually similar but somewhat less severe than their full-scale counterparts. A simplified analysis is presented to account for the lower temperatures observed in the models. Some recommendations are made with regard to physical modeling of the aircraft postcrash fires.

David R. Blake, Richard G. Hill

Eighteen tests were conducted in a 640-cubic foot simulated class D cargo compartment test article. Various ceiling lining materials, cargo loading configuration, air leakage rates, and fire sources were examined in a effort to determine the conditions in this project passed the requirements of FAR 25.853 and 25.855 (vertical and forty-five degree Bunsen burner lab tests); however, they did not always successfully contain the cargo fires. The major conclusion of this study is that FAR 25.853 and 25.855 do not insure adequate burn-through resistance of class D cargo liners subjected to realistic fires.