SHOULD BE FITTEST OF ALL MEN

Dominion, Volume 28, Issue 283, 27 August 1935, Page 8

SHOULD BE FITTEST OF ALL MEN

Rigid Tests For Air Pilots

EXAMINERS DEMAND 100 PER CENT. EFFICIENCY

M ho are the fittest, class of men—wrestlers or cross-conntry runners? After being informed by the Director of Medical Services, Colonel F. T. Bowerbank, of the medical requirements insisted on under the air navigation regulations, one must conclude that, unknown to most people, commercial air pilots are the fittest of all from the point of view of all-round efficiency of physical and mental faculties. Because commercial pilots have lives in their charge, because aircraft will not fly by themselves, only men of 100 per cent, physical and mental efficiency are granted licenses. - That is not all, however. Commercial pilots must pass medical tests every six months, after any accident in which they may be involved, and ar any time upon having flown 125 hours within 30 days. Moreover,' such examinations must be passed at the expense of the pilots. The medical test for A licensed pilots is strict, but it is not as searching or uncompromising as the test for B pilots. The former class are concerned with their own lives; the latter with the lives of other people as well. To gain a B commercial license, a pilot must satisfy two medical men—one a general medical practitioner, and the other an eye, ear, nose and throat specialist. Certificates for B licenses are acceptd from certain nominated medical men in the various centres who have or should have both the experience and the proper equipment for tests. The standard of fitness and efficiency required by the Royal Air Force is' as high as any standard in the world anil some say it is the highest of any. The authorities in New Zealand are desirous that the standard in New Zealand shall be maintained at the same level. Aim for Future. “There is no doubt that the ideal to be aimed at,” said Dr. Bowerbank, “is to establish one central board, or proper boards in the four centres. It is certain that that will be done for the protection of the public as commercial aviation develops.” Cardiac efficiency and nervous stability of candidates are considered specially important. Flying at heights from 10,000 to 20,000 feet and over may affect the cardiac efficiency of most men. It must be ascertained that the candidate shall not be affected adversely. One whose cardiac efficiency is not 100 per cent- may faint at great heights. The most efficient pilots in other respects have recorded such embarrassment, finding that they have dropped 2000 feet before recovering from faintness. The vital capacity test is one of the very important ones on the cardiac and respiratory side. The instrument used is the spirometer, or breath measurer. Candidates must be able to displace 5000 cubic centimetres at least by blowing with one breath into the recording apparatus.

Another test is to blow into a tube and force upward a column of mercury to 120 millimetres or over. Still another test is to hold that column with the breath for 50 seconds while the pulse rate is watched every five seconds. If the pulse rate beings to increase and run to over 140 to 150 a minute, a drop in cardiac efficiency is shown. That is probably due to what is called the abdominal venous pool. Holding the breath must be achieved for at least 65 to 70 seconds. The vital capacity of a. man who cannot do that comfortably is not up to full grade. Those are parts of the special tests for the general examination. Specialists then test candidates for nervous stability and in relation to eye, ear, nose and throat conditions. Eyes—and Hazards. First of all the sight must be normal. Colour vision must be equal to the very high standard required by the Marine Department. A definite percentage of people are colour blind. Men absolutely normal in other respects have been turned down for colour blindness Eyesight is very important and is tested in new ways for colour vision. The Ishihara system is used, and often cannot be passed by candidates who have no difficulty in passing the old test of selecting certain coloured wools.

The Ishihara system is one of cards with mottled colours of all shades from primary colours to pastel tints embody, ing figures and certain patterns to be detected and traced. The cards run in a series with the background and the figures merged more and more. Occular muscle balance must be perfect in commercial pilots for it has been established definitely that lack of true muscle balance is a common cause of accidents in landing. People suffering from squint and other lack of muscle balance may land too steeply. What is known as the “convergence” test is applied to test judgment of distances with varying foci. One-eyed men never would bo passed for entry to the commercial flying class, although some good pilots who have lost the sight of one eye remain efficient. Muscle Sense.. Reaction of the semi-circular canals and the sensibility of the vestibular apparatus aLso are tested. Height and atmospheric changes affect people in different ways. For instance, deaf people are not challenged merely because they cannot bear, but are challenged because of the effect on the muscular and stability sense. The middle ear equalises the pressures on the outside and the inside and has an important bearing on muscle sensation. In addition, good hearing enables a pilot to detect changes In the sound of the functioning of engines. Airmen should be able to adjust their semicircular canals to various atmospheric conditions and that has a bearing on prevention of giddiness and sickness. Sensibility of the muscles generally is important. The tilting chair test is applied. Candidates are blindfolded and placed in a chair that is tilted at various angles, and they are required to judge the position they are in from time to time. That is possible through efficiency of what is called the deep muscle sensations.

High blood pressure is a condition avoided. It indicates a state of inefficiency and may increase at greater heights. War experiences showed that those who had early breakdowns generally were those who had higher blood pressure and fast pulses. Slow pulse in subjects always is liked because such subjects are more stable.

Nervous reactions should not be abnormal and the “temperamental’’ person is not. liked. Good general physical and mental balance is the keynote.