Incidence of airsickness among military parachutists.

This study describes the incidence of airsickness among military parachutists and analyzes the factors involved in its occurrence. Each of 45 healthy male subjects (28 students and 17 advanced parachutists) was studied. Each student participated in five parachute-jump exercises (one daily) and each advanced parachutist participated in one exercise only (proficiency). A questionnaire used for the diagnostic evaluation of motion sickness symptoms was completed by the subjects after each training exercise. A positive diagnosis of airsickness was established for 64% of the students on their first jump and for 35% of the advanced paratroopers on their proficiency jump. By the fifth jump, only 25% of the students experienced airsickness. This suggests that some students developed tolerance to airsickness after five consecutive exposures to inflight vestibular stimulation. Airsickness among student and advanced paratroopers occurred during the transport flight. This can be attributed to vestibular stimulation resulting from the aircraft maneuvers and inflight air turbulence.