Constantine P. Sarkos

A 2-foot square stainless steel panel was constructed with the same dimensions between the fuselage skin and cabin wall as those of a titanium fuselage previously exposed to an external fuel fire. The panel was subjected to a 2 gallon per hour kerosene burner which simulated the heat flux and temperature from a large JP-4 fuel fire, as existed during the titanium fuselage test. The purpose of the panel tests were to determine if the phenomena observed during the titanium fuselage test could be duplicated on a small scale, and also to test various sealant/insulation combinations superior to those used in the titanium in order to ascertain the degree of improvement in environmental conditions which would result. Testing of the panel utilizing the same materials found in the titanium fuselage caused phenomena and temperature distribution very similar to those observed during the full scale test, thus giving credence to this test method as being representative of what would occur to a titanium or stainless steel aircraft during a post crash fire. The titanium insulation tested without any cabin pressure sealant caused a flash-fire. However, two commercially available high temperature insulations also tested without any sealant maintained survivable conditions for at least 15 minutes. Viton, a hydroflourocarbon elastomer, was found not to flame or cause a flash fire under conditions which silicone did (the titanium fuselage had a silicone cabin pressure sealant). The propensity of the formation of a flash fire was strongly influenced by the compactness of the insulation and the presence of any voids or passageways between the fuselage skin and cabin wall interface.

James Teng and James M. Lucas

A carbohydrate derivative was designed as a gelling agent for turbine fuel. The gelling agent is effective in reducing the fire hazard of the fuel. The free flowing gelling fuel could be adapted readily to existing fuel systems. The rheologicial profile of this gelled fuel was established over a range of conditions, by means of a rotating viscometer, Rotovisco Viscometer, equipped with special heads. Among the rheological parameters which were measured, the viscoelasticity of the gelled fuel appears likely to be a major factor in contributing to the crash safe character of the fuel.

Pertinent physical properties and microbiological data were also complied to demonstrate that the fuel gelled with the carbohydrate based gelling agent is compatible with present aircraft fuel systems.

George E. Rowland, Carl T. Reichwein

The concept of a pilot warning instrument (PWI) is that of a relatively simple and inexpensive device which could be used to aid aviators in the visual detection and evaluation of other aircraft in their vicinity, giving the aviator ample time to select and then make an appropriate colIision avoidance maneuver if necessary. Until the present study research on collision avoidance through the use of a PWI has focused primarily on hardware development.

The functional analysis of PWI systems that is presented in this report, is intended to disclose the role of the pilot in such systems and to describe the intricate relationships between the pilot, the PWI, and the operational aeronautical environment. Thirteen general functions are define and illustrated; five performed by the PWI and eight by the pilot. The PWI functions are exemplified by references to hardware systems in use; the pilot functions are described through the use of mathematical models and empirical data.

The general functions of PWI systems are structured into three categories of Pilot-PWI systems. The major independent characteristics of these systems are then used to form system generation matrices. It is shown that over 70,000 different systems can be formed from these matrices. Recognizing the impossibility of dealing with such a number of potent i a I PW I sys terns, an optimization technique and computer simulation layout are described that could be used in the selection of a limited set of optimal PWI characteristics.

Ralph A. Russell, Jr.

A variety of regular and modified hydrocarbon-turbine fuels, one nonhydrocarbon fuel, and reticulated polyurethane foam filled with neat fuel was subjected to small-scale impact tests to determine burning, misting and splatter characteristics of the fuels. The results of this study conclude that it is entirely feasible to retard the ignitibility, combustibility, and flow characteristics of current hydrocarbon fuels by increasing their apparent viscosity. The study showed that non-Newtonian gelled fuels performed better than other modified fuel candidates and better than the reticulated polyurethane foams filled with neat fuel.

This method of test covers a procedure for measuring the smoke generation characteristics of solid materials and assemblies in thickness up to and including 1 in. (25.4 mm). Measurement is made of the attenuation of a light beam by smoke (suspended solid or liquid particles) accumulating within a closed chamber due to non flaming pyrolytic decomposition and flaming combustion. Results are expressed in terms of specific optical density, which is derived from a geometrical factor and the measured optical density (absorbance), the single measurement most characteristic of the "concentration of smoke." The photometric scale used to measure smoke by this test method is similar to the optical density scale for human vision.