HUMAN PROBLEMS IN MILITARY AVIATION 



By Detlev W. Bkonk 



Professor of Biophysics and Director of the Johnson Research Foundation, 

 University of Pennsylvania ; Coordinator of Research, Office of the Air Surgeon, 

 Headquarters Army Air Forces 



One of the memorable experiences of this war is to stand at eve- 

 ning in the great court of Trinity College, Cambridge, outside Isaac 

 Newton's rooms, and watch the flying forts return. Against the soft 

 English sky they move in stately formation, seeming to proceed 

 slowly because of their great height. Their silhouettes, floating by 

 the hundreds through the wisps of clouds, move one with admiration 

 for man's mechanical genius that has driven his machines into the 

 skies, against the force of gravity. 



A little later, in the gathering dusk the fortresses roar down the 

 runways of their scattered fields, and the machines are revealed as 

 mere instruments of human crews. Waist gunners sit casually in their 

 openings, waving as they pass; bombardiers are in their transparent 

 cages ; pilots taxi their ships to rest. They are men returning from 

 a mission made doubly hazardous by enemy action and the dangers of 

 an environment unnatural to man. These are the crews who make the 

 majestic armadas of the air a symbol of man's new freedom from 

 natural limitations, gained by courage and by science. 



The history of aviation is a long record of man's restless urge to 

 exceed the physiological restrictions of his body. It first appears 

 in mythology and ancient literature as a desire for the birds' freedom 

 from the gravitational tie to earth. Yet, when in 1783 man was at 

 last freed from his earth-bound life, he was but started on the con- 

 quest of his limitations. Each new power provided by the physical 

 sciences has placed new stresses on the human body and has carried 

 man into environments to which he has not been adapted by the slow 

 process of evolution. 



The first of these limiting conditions appeared soon after the pioneer 

 balloon ascent. For by 1803 the science of aeronautics had so far pro- 



1 Read April 20, 1944, in the Symposium on Wartime Advances in Medicine. Reprinted 

 by permission from Proceedings of the American Philosophical Society, vol. 88, No. 3, 

 September 1944. 



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