The Effects of Multiple Aerospace Environmental Stressors on Human Performance

An extended Fitts' law paradigm reaction time (RT) task was used to evaluate the effects of acceleration stressors on human performance in the Dynamic Environment Simulator (DES) at Armstrong Laboratory, Wright-Patterson AFB, OH. The DES is a 19 foot radius man-rated centrifuge. This effort was combined with an evaluation of the standard CSU-13 P anti-G suit versus three configurations of a "retrograde inflation anti-G suit" (RIAGS) manufactured by the David Clark Company. Seven subjects participated in four (4) "blend" runs and four (4) data runs on the centrifuge. The 4 blend and data runs corresponded to the number of anti-G suits evaluated (i standard and 3 RIAGS). A blend run consisted of the initial combining of the RT task with G z acceleration for each suit configuration. A data run was identical to a blend run, but it was assumed subjects were now familiar with the experimental set-up. Each run consisted of the following acceleration profiles: 1) a 4 Gz warm-up for 15s, 2) a 1 minute rest at baseline (1.4 Gz), and 3) a modified simulated aerial combat maneuver (SACM) consisting of +4 G z to +7 G z alternating plateaus, each 15 seconds in length. The SACM was performed until peripheral light loss (PLL) ; physiological discomfort occurred (usually due to anti-g suit configuration), or fatigue. Results indicated that RT and error rates increased 17% and 14% respectively from baseline to the end of the SACM and that the most common error was pressing too few buttons.