This Month in Aerospace Medicine History: November

NOVEMBER 2000

Personality and aircrew stress (NASA-Ames Research Center, Moffett Field, CA; U.S. Army Recruiting Command, Command Psychological Operation, Fort Jackson, SC; University of Bergen, Bergen, Norway; University of California-Davis, Davis, CA): “This study was conducted … assessing the impact of captain’s personality on crew performance and perceived stress in 24 air transport crews … Three different personality types for captains were classified based on a previous cluster analysis … Crews were comprised of three crewmembers: captain, first officer, and second officer/flight engineer. A total of 72 pilots completed a 1.5-d full-mission simulation of airline operations including emergency situations … Crewmembers were tested for perceived stress… High performance crews (who committed the least errors in flight) reported experiencing less stress in simulated flight than either low or medium crews. When comparing crew positions for perceived stress over all the simulated flights no significant differences were found. However, the crews led by the ‘Right Stuff’ (e.g., active, warm, confident, competitive, and preferring excellence and challenges) personality type captains typically reported less stress than crewmembers led by other personality types.”¹

Maintainer human factors (Johns Hopkins University School of Hygiene and Public Health, Baltimore, MD): “Aeromedical studies of human factors have focused on the pilot and pilot error rather than on aircraft maintenance workers and maintenance error. This is a report of a survey on medication use in a group of U.S. Air Force aircraft mechanics. … A questionnaire was used to retrospectively examine aircraft mechanic medication use, side effects experienced, and return to work. … Of those surveyed, 67% (26/39) returned to work while taking medication that could potentially impair job performance. … For flying safety reasons, occupational medicine education for aircraft mechanics and their supervisors should address on-the-job use of prescribed medication and self-medication.”²

NOVEMBER 1975

Predicting motion sickness (Pacific Missile Test Center, Point Mugu, CA): “[A] motion sickness questionnaire can be used to predict susceptibility to motion sickness or flight training success … There is a discussion of the theory that motion sickness results from conflicting perceptual inputs. This theory is related to aircraft operating conditions. Scores on a personality test which appear to be related to similar perceptual phenomena are related to aviation success. One phenotype, field independence, seems to be promising in this regard. In addition to use of this finding in aviator selection, it is felt that studies of this trait, as it relates to an ability to reconcile conflict and to motion sickness insusceptibility, should be conducted.”³

How eyeballs work (San Jose State University, San Jose, and NASA-Ames Research Center, Moffett Field, CA): “Stimulation of the vestibular system by angular acceleration produces widespread sensory and motor effects. The present study was designed to study a motor effect which has not been reported in the literature, i.e., the influence of rotary acceleration of the body on ocular accommodation. The accommodation of 10 young men was recorded before and after a high-level deceleration to zero velocity following 30 s of rotation. Accommodation was recorded continuously on an infrared optometer for 110 s under two conditions: while the subjects observed a target set at the far point, and while they viewed the same target through a 0.3-mm pinhole. Stimulation by high-level rotary deceleration produced positive accommodation or a pseudomyopia under both conditions, but the positive accommodation was substantially greater and lasted much longer during fixation through the pinhole. It is hypothesized that this increase in accommodation is a result of a vestibular-ocular accommodation reflex.”⁴

NOVEMBER 1950

Coronary disease and flying (Northwestern University Medical School, Chicago, IL): “Since we are here concerned with flying, we must have some ideas of the hazards involved for a group of patients who should be at rest and avoid anoxia. During the war we were forced to move many patients with myocardial infarctions at all stages of the disease. With proper sedation, insured rest in a bed or cot en route and adequate oxygen we had no trouble. We did not feel in any instance that the patients were harmed by being moved even though there was no alternative.

“Flying personnel (operators) who have any symptoms or signs of coronary disease should be advised not to fly because we have no objective means of estimating coronary reserve. We cannot prognosticate what an emergency might do to the heart in which the demand gets ahead of the blood supply.

“Personally I have been very liberal with patients who have entirely recovered from myocardial infarction and have allowed them to fly commercially providing they were having no symptoms of coronary insufficiency. Since the pressurized cabins are in general use, I feel that the hazard of flying has been considerably diminished for the patient with a cardiac problem. Even those who have histories of mild insufficiency symptoms have been allowed to fly but warned to limit their activity while they are at high altitudes. Perhaps I have been over liberal or lucky in granting these privileges to some patients, but I have a deep conviction that the speed of air travel more than compensates for the fatigue encountered in long, tedious boat or train journeys.”⁵