Trimble E J
Air Accidents Investigation Branch, Department of Transport, Defence Research Agency, Farnborough, Hampshire, UK.
Toxicology. 1996 Dec 31;115(1-3):41-61. doi: 10.1016/s0300-483x(96)03494-4.
The prime factors influencing survivability from 10 major fire-related public transport aircraft accidents were assessed. Regulatory requirements were assessed against derived criteria and alternate concepts evaluated to identify a preferred strategy for enhanced survival; the provision of passenger protective breathing equipment (PPBE) was part of the twin strategy selected. PPBE tests conducted by the UK Air Accidents Investigation Branch using lung simulators and semi-controlled complex challenge combustion atmospheres generated from defined mixtures of cabin interior materials indicated that Hopcalite filters could provide satisfactory protection against carbon monoxide, hydrogen cyanide, hydrogen fluoride, hydrogen chloride, nitrogen oxides, sulphur dioxide, ammonia, acrolein, and other hydrocarbon compounds, for periods up to 30 min. Filtered levels of carbon dioxide (CO2) could be maintained within a 5% limit (inhaled atmosphere + dead space) against such atmospheres containing up to 4% CO2. Concentrations of oxygen downstream from the filters were up to some 1.0% above that present in the challenge atmospheres. Separate lung simulator tests on breathable gas (oxygen) hoods indicated that satisfactory respiratory protection could be provided for periods of up to 31 min. A possible filter modification of the passenger oxygen mask concept is discussed. It is recommended that research should be emphasized on the development of a means (e.g. PPBE) for providing in-flight smoke protection for passengers.