D.E. Cagliostro

Recent safety considerations have sought to lower the electrical conductivity of carbon fibers. Carbon fibers produced from polycryonitrile at low carbonization temperatures (600 degree – 900C) possess low electrical conductivity but do not possess adequate strength. Low temperature processes are described which improve fiber strength but not increase electrical conductivity substantially. The processes result in a carbon fiber with nearly twice the tensile strength compared to the old process. Process development and its effect on fiber properties are reported.

The vast majority of comments endorse the proposals, although some suggest minor modifications to the requirements.

Extinguishing Agent - Method of Operation

Constantine P. Sarkos, Richard G. Hill

This paper discusses full-scale transport aircraft cabin fire tests conducted in the United States under postcrash fire conditions. The logic behind the development of fire test scenarios is described, including a comparison of fire involvement by external fuel fire penetration through an opening or by fuselage burnthrough. Early full-scale tests in the 1960's and 1970's that furnished data on the characteristics of cabin fires are briefly described. Past test activities addressing facets of the fuselage burnthrough problem are also discussed. The impact of environmental factors (such as wind, door opening configuration, and fuselage orientation) on fire penetration through openings and the resulting cabin hazards is discussed on the past test activities. The majority of the data presented in the paper are from a recent full-scale test to determine fire/hazard progression in a postcrash cabin fire environment with emphasis on post-flashover conditions, to examine factors affecting occupant survivability, and to evaluate the performance of a protective breathing equipment filter. The paper often discusses and cites past studies addressing important cabin fire characteristics and concepts, such as flashover, stratification and survivability.

I.I. Pinkel, P. Hacker

Detection of a combustible gas in the atmosphere of a spacelift is an essential part of a complete spacecraft fire protection system. Two similar but different techniques may be useful in this respect.