Greyout, blackout e perda de consciência induzida pelas aceleraçöes na Força Aérea Brasileira: um estudo em 1991-92 / Greyout, blackout and loss of conciousness induced by acceleration in the Brazilian Air Force: a study in 1991-92

RESUMO

A national survey wiyh high and medium performance aircraft pilots on the incidence of symptoms duee to + Gz acceleration has been performed, in order to make up a human centrifuge physiological training profile directed to the needs of the Brazilian Air Force pilots. Anonymous questionnaires were sent to flight Squadrons of F-5, AMX, Mirage F-103, Xavante AT-26 and Tucano T-27. They consisted of inquiries about the ocurrence of visual symptoms and/or loss of consciouness during + Gz maneuvers, and post G-LOC symptoms, 23 pilots (11.92 per cent) reported greyout and/or loss of peripheral vision; 40 (20.72 per cent) blackout; 20 (10,36 per cent) G-LOC. Those who reported LOC also reported post G-LOC symptons (100 per cent), being 16 (80 per cent) gradual and 4 (20 per cent) instantaneous. Incidence of G-LOC was not found to depend upon the type pf aircraf flown (p>0.05). Considering the pilots who reported G-LOC, 80 per cent were preceded by blackout, which could allow them to relieve + Gz load before they would reach their endpoint for the ocurrence of G-LOC. For these reasons we recommend intensive human centrifuge training periodically, similar to the hypocia-recognition symptoms test in the low-pressure chamber, not only for high performance aircraft pilots but as well as for any pilot who can perform aerobatics (thus exposing himself to the adverse effects of "pulling G"), in order for each pilot to recognize his consciousness endpoint when undergoing + Gz maneuvers, in a controlled and safe environment.