As air traffic is expanding rapidly, more and more people are exposed to the possibility of accident. Although safety per passenger-seat mile continues to improve; because of the increasing capacity of aircraft this does not necessarily mean that the accident rate per trip follows the same pattern. The majority of accidents happen during take-off and landing but they are not necessarily associated with loss of life. The application of crash survival factors to structure and improvement in the restraint equipment for crew and passengers; the provision of rapid exit facilities and the reduction of the chances of conflagration have all played their part in improving the chances of survival.

Accidents involving collision with high ground on the other hand are almost always catastrophic and usually fatal to all the occupants. The statistics issued by I.A.T.A. show that some 40 per cent of all passenger deaths, in the airlines contributing figures, are due to this cause. Because of this it is imperative to consider every aspect of them that might lead to their reduction.