Acceleration Stress Effects on Pilot Performance and Dynamic Response

Several brief studies were conducted to assess the effects of a wide range of acceleration environments, varying from zero gravity to high sustained accelerations, on pilot performance and dynamic response. The results indicated that the control performance decrements observed at high sustained accelerations were attributable to decreased pilot gains and corresponding reductions in open-loop system crossover frequency. Limited results for extreme vibratory accelerations suggested that performance deterioration was associated with a reduction in pilot lead equalization (and a corresponding reduction in open-loop crossover). Under short-term weightless conditions, performance in a simulated control task was appreciably poorer than under comparable 1 g conditions for one of two sets of simulated vehicle dynamics investigated. The reason was attributed primarily to increased pilot excitation of the vehicle´s lightly damped short-period mode. Soviet data, available from Voskhod flights, indicated that cosmonauts did not perform as well in a simulated control system as during ground training sessions.