Seven exemplary antimotion sickness drugs and three 'individually treated' placebos were investigated in ten men during twenty-four aerobatic maneuvers in an A1E 'Skyraider' aircraft and in performance of the Pensacola Slow Rotation Room Dial Test. The rank order of drug effectiveness and of subject susceptibility under each condition was determined and compared. Individual difference in drug effectiveness was significant at the .01 level or better and was similar under the two conditions. Susceptibility to motion sickness in the SRR was generally a good predictor of susceptibility in aerobatics in eight subjects, but in the remaining two it was grossly in error. A combination of scopolamine and d-amphetamine was by far the most effective of the drugs tested under both conditions. (Author).