To help develop a specification for equipment providing personal respiratory protection in the event of aircraft fire a study was carried out to quantify ventilation and oxygen consumption during escape from a Trident aircraft. Data were gathered using the P. K. Morgan #x2018;Oxylog#x2019; apparatus after its response time to rapid changes in inspired to expired oxygen concentration difference was assessed using a bench test. The #x2018;Oxylog#x2019; had a lag time of 30-32 s and a 5-95 response typified by a half time of 20 s. The data gathered were corrected in the light of these findings. Fourteen male subjects aged 17-38 years were studied under two conditions. Four mass evacuations each involving 40 people; a total of nine subjects escaping from the front rank over eight seats being monitored. Six evacuations each involving only two people escaping from the rear of the cabin; a total of 11 subjects escaping over 14 seats being monitored. Escape was made over the seat backs, down an escape chute to a position 12 m from the base of the chute. Resting minute ventilation (mean 16#xB7;7 1 STPD) and oxygen consumption (mean 0#xB7;41 min#x2212;1STPD) were similar before both evacuations. There were no significant differences between the two conditions either during, or up to 180 s after escape. Ventilation and oxygen consumption were greatest in the recovery period. The highest oxygen consumption seen was 2#xB7;081 min#x2212;1and maximum minute ventilation was 641. Mean total oxygen consumption for the escape and a 150s recovery period was 2#xB7;411 (s.d. 0#xB7;64, max. 3#xB7;11) for the mass evacuation and 2#xB7;971 (s.d. 0#xB7;68, max. 4#xB7;09) for the two person evacuation. The mean total amount of gas inhaled during the same time period was 89#xB7;31 (s.d. 25#xB7;6, max. 121#xB7;3) for the mass evacuation and 99#xB7;01 (s.d. 26#xB7;2, max. 137#xB7;3) for the other. These was no correlation between ventilation or oxygen consumption and either escape time, body weight, height or age.
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