[Prediction of G-load (Gz) tolerance based on various functional tests]

The purpose of the present study was to analyze and sum up the data on the methods of predicting g-tolerance (+Gz) utilizing various functional tests within the program of medical flight certification. The study involved 478 fighter pilots who were examined at the Central Military Scientific/Research Aviation Hospital. The age of examinates varied from 25 to 50 years (35 yr. on the average). Along with healthy subjects there were also pilots with the history of vascular-autonomous instability, anamnesis of syncope, myocardiodystrophy, myocardiac and atherosclerotic cardiosclerosis, and some other disorders. As a result, a correlation was established between the tolerance of lower body negative pressure at -50 mm Hg and standing tests. No link was noted between tolerance of the subjects to moderate hypoxia (H = 5,000 m for 30 minutes) and +Gz-loads at 3 and 5 units for 30 seconds. Neither was there evidence of correlation between tolerance of standing tests including their modifications and g-loads. Pearson association coefficient ra = 0.01. Comparison of the tolerance to +Gz at 3, 5, and 6 units without the anti-gravity suit and static loads at 120, 160, 200, and 240 kg/s during 30 seconds each gave an agreement of 67%. However, the statoergometry test revealed a poor tolerance of static loads only in 17.2% out of 29 pilots with low g-loads tolerance. Hence, the association coefficient appeared to be equal to 0.06 denying any predictive link. This absence of reliable predictive correlation between the tests in use was extenuated by different physiological mechanisms of adaptation.