The high level of the long lasting acceleration with both an extensive gradient of the acceleration onset and vector alterations belong to the flight specificity in a cockpit of agile aircraft with high manoeuvring capabilities. In these cases the so-called push-pull (PP) effect has its particular significance. This means the tolerance decrease to the plus gravitational acceleration turns up after an exposure to the microgravity on the acceleration level between zero and +0.8 Gz or after previous action of negative acceleration values. The resulting activation of the sympathicus during plus gravitational acceleration process is up to several seconds behind time and pilot's performance is reduced. At the same time both an impairment of the threshold of the vision failure and G-LOC occur. The gravitational acceleration fatigue effect escalates, too.

Department of Flying Safety Institute of Aviation Medicine 160 60 Prague 6 Gen Piky 1 Czech Republic