Application of the compartmentalization/airlock concept to aircraft and tolerance of lung to rapid decompression.

The incidence of pulmonary hemorrhage of different laboratory animals undergoing rapid decompression was found to be markedly decreased by applying the compartmentalization/airlock concept to simulated pressurized aircraft. It was observed that, in protected rabbit, mouse, and rat lungs, 6 of 24 (25%), 7 of 24 (29%), and 6 of 24 (25%), respectively, exhibited a few petechial hemorrhages following rapid decompression. In unprotected animals, however, all 72 lungs showed slight-to-very-severe degrees of decompression-induced hemorrhages. The percent of mortality of the unprotected animals undergoing rapid decompression was 47%, while there were no deaths in protected animals. The incidence of such pulmonary hemorrhages and the mortality of experimental animals indicate that compartmentalization, combined with an adequate airlock, would be of great value in protection against accidental decompression of pressurized aircraft.