The following prepns. were tested during simulated aircraft turbulence: placebo; N(alpha-methyl-beta-dimethylaminoethyl) -phenothiazine HC1 (Lergigan), 25 mg.; N(2[image]-dimethylamino-2[image] methyl)-ethylphenothiazine HC1 (Phenergan), 25 mg.; and prophenpyridamine (Trimeton), 25 mg. All 3 drugs reduced significantly the incidence of vomiting below that in the placebo group. Phenergan exhibited the greatest protection. Side effects with each drug were slight, an increase in drowsiness being the most apparent effect. The possibility that the effectiveness of Lergigan is due to an admixture with Phenergan is discussed.