RESEARCH STUDIES ON INVESTIGATION OF THE EFFECTS OF SLOW AND RAPID DECOMPRESSION UPON HUMANS AT 45,000 FEET

Tests were conducted to determine the effects of decompression from 8,000 to 45,000 feet at rates from 5 to 30 seconds on four pilot and four passenger subjects. Masks of several types currently in use in transport and business aircraft were worn or donned at varying intervals of exposure. Physiological measurements and cellular enzyme determinations were recorded in all tests, and performance and communication studies were conducted on the pilots. Results of the tests revealed inability of most subjects to complete all pretest instructions. Severe reactions or incapacitation of varying degree occurred in the three subjects exposed to the five-second decompressions. Convulsive movements occurred in two of the subjects who did not apply their masks for periods of about five to six seconds after reaching maximum altitude. Encephalographic changes, indicative of severe hypoxia, occurred in these cases between 17 to 40 seconds after the start of decompression. Performance and communications were adversely affected in all pilots undergoing decompression without wearing the mask; however, enzyme changes were nonsignificant in all except one passenger.