Physiologic and performance measurements in simulated airborne combined stress environments

The Naval Air Development Center's Human Centrifuge was used to assess the effects of repeated exposures to a simulated Air Combat Maneuvering (ACM) environment on various measures of physiological function and psychomotor performance. The environment consisted of a realistic ACM profile that included associated noise, high speed/stall buffet conditions, and increased intra-cockpit temperatures. The effects of varying the subject's seatback angle, as a function of the environment, was also measured. Analysis of the various physiological and performance data revealed the following: 1) heart rate was negatively correlated with tracking accuracy under the combined stress conditions of this study, 2) test conditions that included acceleration and buffet resulted in a significant decrement in tracking accuracy, 3) the addition of increased intra-cocpit temperatures, when combined with acceleration and/or buffet, produced a significant decrease in tracking accuracy, 4) increasing the seatback angle from the vertical partially ameliorated the effects of the other stressors. Details of these findings, as well as results of various biochemical analyses, are discussed.