Physiologic Testing of the T-43 Passenger Oxygen Mask

The passenger oxygen mask planned for use in the T-43 aircraft was tested for 3 hours at 25,000 ft equivalent altitude (282 mm Hg) in an altitude chamber. Ambient temperature was maintained at 65F. Six volunteer subjects were used. Inspired P(O2) averaged 195 mm Hg with a minimum of 122 mm Hg for any subject averaged over a 10-minute period. End-expired P(O2) averaged 143 mm Hg with a minimum of 103 mm Hg for any 10-minute period. End-expired P(CO2) averaged 34.2 mm Hg and respiration rate 14.6 breaths/min. The mean inspired and expired pressures in the mask averaged -0.54 inches of H2O and +0.18 inches of H2O respectively. No deterioration of performance could be detected with psychomotor testing. The mask was well accepted with no reports of discomfort. All runs were completed successfully with no evidence of hypoxia. It was concluded that the mask performed adequately under the test conditions over the 3-hour test period. (Author)