Abstract

A study of over 700 Enroute and Terminal Air Traffic Control Specialist trainees revealed that different kinds of pre-employment, job-related experience had differential value for the prediction of training performance. In general, experience most directly related to air traffic control work was a positive predictor; experience related to communications and piloting was negative. It was also shown that for Enroute trainees only, a composite variable ( AT) representing the sum of Tower, GCA, RAPCON/RATCC, and Center experience had a statistically significant, but small, relationship with ratings of job performance. In contrast, aptitude tests were superior to the experience variables for the predictions of all training course performance measures of both types of trainees, with the exception of Laboratory performance of Terminal trainees.

In the latter instance, 2 AT was superior to the tests. For job performance, it was found that only ratings of Enroute trainees could be predicted by the tests and that although the tests were superior to experience as predictors the relationships were small. As determined in other studies, it was again shown that age at entry into training was negatively related to training and job performance and that the negative relationships were greatest with grades in simulated air traffic control work in the training school laboratories. The findings of the study led to the recommendation that selection of individuals for Air Traffic Control Specialist training be based upon an aptitude test battery And pre-employment, job related experience in tower, GCA, RAPON/RATCC, and Center work.

Abstract

Decompression sickness was studied by use of a special technic for the production and recognition of the disorder in a laboratory animal. Objective evidence is presented for substantiating the use of compression therapy in the treatment of both caisson and altitude types of decompression sickness.

There is suggestive evidence that even very small overpressures may be of benefit in treating or transporting some cases of severe altitude decompression sickness.

The importance of rapid recognition and treatment is emphasized, as well as careful scrutiny of all patients who appear to be “hyperventilating” after decompression, especially those patients with other signs or symptoms of decompression sickness.

Abstract

This investigation was concerned with the effects of breathing 100 per cent oxygen (by mask) at 1 atmosphere ambient pressure for 4 hours on sympathoadrenal, adrenocortical, and metabolic functions in healthy human subjects. Control determinations were made on the same subjects on a separate occasion, the subjects then breathing room air (by mask). Sympathoadrenal activity was appraised by means of urinary epinephrine and norepinephrine determinations; adrenocortical activity was appraised by means of plasma Cortisol and urinary 17-hydroxycorticosteroid determinations; and metabolic appraisal was made by means of urinary creatinine, urea, uric acid, phosphate, potassium, and sodium. Evidence of hyperoxia-induced adrenocortical and sympathoadrenal depression was found—plasma Cortisol concentration, as well as catecholamine excretion, falling below the control levels. Urine volume also was relatively low, as were urinary sodium and phosphate values. Mask discomfort was shown to be an obscuring factor, since it acted oppositely to hyperoxia in many respects.

Abstract

A review of the electroencephalogram in aircrew selection is presented. Attempts to correlate flying aptitude with the electroencephalogram have so far been unsuccessful. Although difficulties have arisen in establishing criteria for rejection of apparently normal individuals, the EEG has been shown to have a definite if limited value in screening aircrewmen for epilepsy. Those with specific paroxysmal patterns should not be accepted for flying duties whether or not a history of previous episodes of loss of consciousness or seizures can be obtained. Hyperventilation and photic stimulation are useful activating procedures but convulsive agents such as metrazol have not proved helpful in identifying epileptics. It is not justifiable to reject a candidate whose neurological history and examination are normal on the basis of nonspecific EEG abnormalities. In-flight EEG recordings are as yet experimental and their interpretation requires simultaneous recording of other physiological variables including alveolar C_o2 and blood pressure.

Abstract

Male Swiss albino mice exposed to 700r whole body X-irradiation while breathing either air or 100 per cent oxygen were explosively decompressed from sea level to a terminal altitiude of 30,000 feet. A second group of mice exposed to X-irradiation only while in an air or oxygen rich environment were maintained for a thirty-day observation period.

On the basis of pooled survival data it is concluded that the use of either an air or oxygen rich environment during exposure to X-irradiation has no effect on the tolerance of mice to explosive decompression as evidenced by immediate survival or thirty-day survival. The expected thirty-day survival proportion of mice exposed to whole body X-irradiation only while breathing oxygen is significantly reduced when compared to the survival proportion of mice breathing air.

Abstract

This paper deals with the study of 158 general aviation fatal accidents in which routine toxicological examinations were performed on the pilots. This represents one-third of the total number of general aviation fatal accidents for the year 1963. It was found that 56 of the 158 cases were positive for blood and/or tissue alcohol, representing 35.4 per cent of the total general aviation fatal accidents study.

All classes of airmen and all pilot ratings were found in the positive alcohol group. The incidence of student pilot involvement in this group was found to be almost twice that in the over all fatal accident population. An interesting finding was that almost one-half of the alcohol positive group crashed within eighteen minutes or less of takeoff. An analysis of total pilot flight time in the positive alcohol group reveals a high incidence of fatal accidents in the low total pilot time range around 300 hours. The positive alcohol group was found to have a night accident rate twice that of the over all fatal accident group.

The paper reveals a much higher incidence of proven alcohol in pilots in fatal general aviation accidents than were previously known. The study adds support to Aksnes finding that relatively low levels of alcohol adversely affect flying performance. The study is an example of the great need for medical and human factors studies in civil aircraft accident investigations. Although the positive alcohol group contributed to over one-third of the general aviation fatal accidents, it is to be noted that this group comprised less than 0.6 per cent of the total general aviation population.