Feasibility study to demonstrate the potential of smoke hoods in simulated aircraft fire atmospheres: Development of the fire model

Abstract The subject of this paper is the development of a fire model producing smoke similar to that which could be anticipated from a burning passenger aircraft in the period before flashover. The simulated aircraft fire smoke was used to test filter and oxygen‐donating smoke hoods as part of the Accident Investigation Branch research programme initiated after the Boeing 737 fire at Manchester in 1985. A relatively simple approach was adopted in which materials used in passenger aircrafts cabins were burned in an enclosed room. The smoke hood exposure tests were then carried out in the same room. The fire model permitted the smoke hoods to be tested for 5‐min periods with an atmosphere approximating to that required and for longer periods with atmospheres with reduced concentrations of the more polar gases. Analytical procedures enabled both challenge atmospheres and filter penetration to be assessed. The evaluation of smoke hoods by Rapra Technology and British Coal demonstrated that filter smoke hoods were capable of providing protection (providing there was sufficient oxygen to sustain life), that carbon dioxide did not cause debilitation and that the heat produced by the oxidation of carbon monoxide was dissipated. Oxygen‐donating systems were also capable of providing protection for the duration of their oxygen supply but it was necessary to prevent the build‐up of carbon dioxide. Other important factors, such as the effectiveness of smoke hood to head seals and the effect of hood donning on aircraft evacuation times, have not been examined in this paper.