AIR SERVICE

Gisborne Herald, Volume LXVIII, Issue 20628, 2 December 1941, Page 8

AIR SERVICE

MEDICAL PROBLEMS

OVERSEAS DEVELOPMENTS

NEW ZEALANDER'S TOUR

(Special to die Herald.)

WELLINGTON, this day. in order that the Dominion mjght benefit from Knowledge gained by the medical' profession in Britain oC the effects of war operations on (lying personnel, it. was decided by the Government to send to England and Canada Lien tenant-Colonel \F. R Chisholm, Assistant Director of Medical Services (Air). He has returned to New Zealand and submitted his report to the Minister of Defence, the Hon. F. Jones, who states that it was realised that personal contact with medical men associated with the Royal Air Force would enable information to be secured which ordinarily would not be procurable by correspondence or through technical publications. It also gave the advantage of seeing special equipment and apparatus in practical use; and of studying the various methods followed in testing flying personnel. ‘‘Thanks to the marvellous progress in the construction of aircraft, safety in flying,” said the Minister, “is to-day almost totally dependent on the health and physical condition of tlie pilots, and it is therefore essential that certain minimum standards should be adhered to by medical men in their examinations and testing, not only of air force candidates, but those who are serving actively. Many helpful and useful proposals and suggestions have been submitted by Lieutenant-Colonel Chisholm. and some of these certainly will be adopted in the Dominion.” Tests for Air Service A survey of his impressions of the latest developments was given to the Herald’s correspondent by LieutenantColonel Chisholm, who said that, as in New Zealand, great care was taken by the Royal Air Force in the selection of its personnel. England and Canada had a central selection committee, and also centralised their medical examination, thus maintaining uniform standards. The candidate’s first interview with the medical selection board was not merely for testing physical qualifications. The examiners took a close interest in the man’s life history. They wanted to know if he played games, and whether they had been of the aggressive type. If lie had been fond of swimming, had he had enough "dash” lo indulge in high dives? Was lie subject lo headaches? These were apt to recur in high flying. Part of this examination is designed to test the stamina and staying power of the potential airman. So thorough is this preliminary examination that 30 or 40 per cent of the candidates fail to get into the flying personnel of the Royal Air Force, although other opportunities arc available to them in that service.

The first test successfully over, the candidate is subjected to specialist eye and ear examinations. His vision and hearing must be perfect, and colour-blindness constitutes a bar to flying. Various reaction tests are applied, and those who have seen the array of instruments in aircraft realise the importance of tests which indicate the degree of co-ordination between eyes, hands and feet.

Though the tests for the Royal New Zealand Air Force are more severe than those applied in the army, Lieutenant-Colonel Chisholm pointed out an important difference between them.

“We will," he said, “accept for the Royal New Zealand Air Force men with fiat feet, club foot, and various weaknesses of arms and legs which will keep them out of the army.” In High Altitudes

Flying at high altitudes is an important develbpment in this war, and as the airman at 18,000 ft. can normally breathe less than half the oxygen available at ground level, there has been a general adoption of oxygen apparatus in service aircraft. Flying at 15,000 to 18,000 ft without oxygen is difficult, and is impossible above 22,0fi0ft. At first, according to Colonel Chisholm, the Royal Air Force personnel regarded the use of oxygen apparatus as “cissy,” but practical experience showed its absolute necessity. One of the traps in high flying is that the lessening oxygen supply brings about changes in a man’s mental and physical condition of which he is not aware. He may feel “on top of the world,” but his perception has really become deadened. Without additional oxygen he comes back from altitude flying much more fatigued. To experience the effects of lessened oxygen at altitudes, airmen do not have to leave the ground. They are tested by the Royal Air Force medical staff in decompression chambers, and Colonel Chisholm saw the crews of the Fortress Bombers being put through the test, of the equivalent of 35,000 ft. in the decompression chamber before they were sent on the bombing rinds which brought disaster to two German battle cruisers sheltering in Brest. Night' Vision and “Black-outs”

Colonel Chisholm mentioned the well known phenomenon of the "black-out” which airmen experience when pulling out of a sleep dive or speedy turn. This is purely a physical effect due to the sudden withdrawal of the blood from the upper parts of the body. Airmen have found an easy way of minimising the trouble—they adopt a douching altitude, with the head as low as possible so that the blood supply is not forced away lo the lower extremities.

Night-vision has been the subject of research, and Colonel Chisholm was asked if the popular view regarding the value of currol diet for night flyers was correct. lie replied that carrots in die diet were valuable, but if the i ight diet was used the airman gets sufficient vitamin A without resource to this vegetable.

“The faculty of goad night vision, however,” added Colonel Chisholm, “is something in-born in the individual, It has been found by many experiments that the best men can see eight times as far as (lie worst'in starlight and moonlight. Airmen are all tested, and those without this quality are utilised for daylight flying. As in New Zealand, the medical officers concerned with the air force pay the closest day to day attention to flying personnel. They are concerned with tlie health of every individual, and in addition to the routine sick parades, medical officers are expected to spend several hours daily in the crew rooms and hangar..