In 1938, Sir Frederick Banting, head of Medical Research at Toronto University, began a physiological research programme designed to protect aircrew “who were about to wage War in the tremendous air battles in the skies over Europe”. Besides starting research on a new oxygen ‘demand’ system (in use by late 1942) his team also studied new flying problems associated with fatigue, noise, vision, nutrition, coldness, high altitude and the effects of high ‘g’. Both Banting and RAE Farnborough knew that future fighter and bomber aircraft would make demands far exceeding the physical capabilities of those who were about to fly them. Something also had to be done to catch up with the Germans who had learned so much from their experience in the Spanish Civil War.
In spite of the lack of funds for military purposes in Canada and in Britain which followed from the pacifist governments of the early thirties, Banting was able to use his prestige, as the discoverer of insulin, to extract sufficient funds for his military research at Toronto University at a time when such research was not allowed in Britain. One of his staff at Toronto was Dr. Wilbur Franks. Although Franks had never flown, he understood the effects on animals and humans of high ‘g’ in tight turns. During a cancer research problem, he had invented a ‘g’ suit for some mice so that they could withstand the high ‘g’ of a centrifuge. This he did by kitting out each mouse with a condom, immersing the condom-coated mouse in water up to its neck in a test tube — also immersed in water for protection — and by placing the test tube in his centrifuge. Both tube and mouse withstood the strain of 150 ‘g’. In spite of this huge centripetal force, its heart and all its bodily functions continued to work perfectly, and the mouse walked away unharmed. Without such protection, it, and the test tube, would have been crushed to a pulp.
Franks perceived that by surrounding the human body with a similar rigid water jacket, the water in the jacket would then apply a pressure to the outside of the body exactly equal and opposite to that of the blood inside the body as ‘g’ was applied, and so prevent blood from collecting in the lower parts of the body. Blood starvation to the upper parts of the body could not then occur. The retina, the brain, the lungs and the heart could continue to function normally. The advantage of being able to see and to remain fully conscious in very steep, high speed turns of six to eight ‘g’ would give British and her allies’ pilots a huge advantage over the Germans and allow them to turn inside them in a dogfight.
How does ‘g’ — or centripetal force — occur? The ‘g’ in an aircraft increases as its TAS squared divided by its radius of turn. It follows therefore, that provided the aircraft can cope, for a given rate of turn, the ‘g’ suffered by the aircraft and pilot depends very much on its speed. The first limitation on the ‘g’ a pilot can pull in an aircraft obviously depends upon the aircraft’s ability to give the extra lift required without it reaching stalling incidence. If there is sufficient speed, the next limitation is upon the ability of the pilot himself to withstand the extra ‘g’. Finally, there is the strength of the aircraft itself. Aircrew ‘grey out’ between four to six ‘g’ — depending on their fitness and sitting posture. They ‘blackout’ from five to seven ‘g’. If ‘g’ between five to seven is prolonged — perhaps more than a few seconds — aircrew become unconscious. They quickly become unconscious — perhaps in a couple of seconds — if the ‘g’ is imposed suddenly and is more than seven ‘g’.
Most fighter aircraft in WW II had sufficiently low wing-loadings for them to be able to deliver about seven to eight ‘g’ maximum without stalling at an IAS of 300 knots and above. Stall warning in the turn was given by ‘judder’ on the stick, caused by a wing-root breakaway in the airflow hitting the tail surfaces. The pilot then relaxed back pressure on the stick. In a prolonged turning fight where the enemy aircraft maintained a fairly constant height in the turn, the engine powers of WW II fighters were insufficient to maintain speeds much above 240 knots IAS — usually they were far less — particularly at high altitude. The maximum ‘g’ a Spitfire could pull at this IAS at any altitude without stalling would be about five ‘g’. With the extra thrust (to overcome the increased drag of a high ‘g’ turn) not available from the engine, the Spitfire lost speed still further in the turn. There was therefore no need for a ‘g’ suit unless diving turns were made in a prolonged turning combat. Pilots would always pull the steepest (ie, the smallest radius) turn possible without the ‘judder’, to draw a bead on the enemy. The target, if he had kept his eyes open and had spotted his attacker, would hope that he could turn tighter still and prevent a deflection shot on him, and gradually turn inside his attacker so that he finished up astern of him within a few gyrations. During such prolonged fights, the only recourse open to an aircraft about to be fired at was a quick roll into the turning direction, a dive and a quick pullout at the bottom of the dive. It was here that the ‘g’ suit was a life-saver. The dive away and pull-out would not blind the ‘g’ suited pilot, but would black out the enemy on his tail for a sufficient time for him to lose his bearings and lose sight of his quarry. The pilot with a ‘g’ suit could turn his aircraft with up to 7½ ‘g’ applied for longish periods.
However, the commonest set of circumstances where the ‘g’ suit was very useful was in the positioning phase of a fighter v fighter or fighter v bomber combat. The approaching attacker might need to have a 50-75 knot excess speed during this phase and so be much more vulnerable to ‘g’ effects. If the target was to see his enemy diving down on him, say, from his port quarter, he would immediately turn left towards his attacker as steeply as possible at the moment just before he came into firing range, to prevent a deflection shot. If he did not choose exactly the right moment to do this, the attacker with a ‘g’ suit might still be able to turn inside his quarry and get on his tail. Without a suit, it would not be worthwhile to do this.
The suit was made ‘top secret’ by 1940, for, if discovered early by the enemy, it would obviously lose all advantage. Nevertheless, Wing Commander D’Arcy Greig, of Schneider Trophy fame, could not resist carrying out the brief trials on the second prototype suit in a Spitfire, in full view of his relatives and friends. The brief tests showed that this early version of the suit could protect the pilot up to eight ‘g’ — for the short periods that such a high ‘g’ could be applied and maintained.
In February 1941, Doctors Franks and Banting determined to come to Britain to continue their work, where the prospects for aircraft tests were far better. Tragically, Banting — and his aircraft crew — died in their Lockheed Hudson Atlantic ferry plane. It failed to maintain height on one engine out of Gander and crashed at night in a field a few miles away. Dr Franks wisely followed by sea, a few months later.
With these delays, it was not until November 1942 that AVM Sholto Douglas — who had relieved Dowding as C-in-C Fighter Command — was able to say “I favour the adoption of the Franks suit for operational use”.
By this time, the FAA had already carried out their in-service trials. They used 807, 801 and 885 Seafire Squadrons taking part in Operation ‘Torch’. Afterwards, in December 1942, the pilots reported favourably. Lt (A) A. C. Powell, RNVR, said: “Had it not been for the suit I should have blacked out, for the aircraft was shuddering (180-200 knots) at the time”. Another said that he was able to pull round so sharply in a steep turn at Oran that the Dewoitine 520 on his tail ‘spun off’. Although an IAS of only 180-200 knots could not have given enough lift to black out any pilot — with or without a suit — it was obvious from the pilots’ reports that the suit gave them confidence. But how much this was due to the suit at Oran — or the superior fighting qualities of the Seafire — it would be hard to say.
Nevertheless, their reports showed that in spite of all the extra trouble of fitting, filling, emptying and removing the suits in the chaos of a carrier’s flight deck, the FAA pilots liked it.
It was therefore disappointing that for Operation ‘Husky’, the four squadrons of Seafires in Indomitable were not allowed to use it, for secrecy reasons. It was to be kept for the invasion of Normandy. Both Lt/Cdr W. H. ‘Moose’ Martyn of 880 Squadron and Lt/Cdr R. B. Haworth of 899 Squadron complained of this officially, but to no purpose.
By January 1944, with the assistance of Messrs Dunlop, some 8,000 suits were made in 17 different sizes, nearly half of them being for the FAA. Each of the 17 sizes was capable of a myriad contortions in addition — by means of lacing, adjustable webbing, zippers and braces, all pulling in appropriate directions upon the equally myriad shapes and sizes of the fighter pilots. A gallon of water gave the calves, thighs and the lower abdomen full ‘g’ protection. A small airspace was left to retain buoyancy in case of a baleout over the sea. The suit could be worn on the ground without too much discomfort for about six hours — over a pair of pyjamas. However, those who force-landed in NormandyTrom 3 Wing found that a couple of hundred yards was all they could manage while the suit was still full of water, even when running away from the Germans.
Although by November 1942 it was already Fighter Command’s policy to issue their pilots with the suit by May 1944 in time for ‘D’ Day, they made such a poor job of ‘selling’ it to the RAF that very few of the RAF pilots took up the offer. The FAA were the only serious takers. Those who were flying desks, not aeroplanes, in the Air Ministries of Canada and Britain, had to find a reason for the pilots’ seeming ingratitude. Canadian HQ quickly found one.
The ‘sellers’ had made the stupid mistake, they said, of asking the fighter pilot himself what he thought of the suit. No wonder he had turned it down for: “this untouchable hero of all heroes . . . felt that the suit complicated his life style and detracted from his macho image”. To explain the FAA’s acceptance of the suit, they said that, instead of living like the RAF “On an airbase, close to pubs and young ladies and all the amenities civilisation has to offer,” the FAA lived in a much harsher climate and were therefore “more survival orientated”. They therefore welcomed the suit. The letter — to the Canadian Defense Ministry in Ottowa — then described this environment in such stark terms that it would not have been believed even by a Hollywood script writer. Such was the poor state of communications between the scientists, the Air Staff and those chosen to test the suit, in 1942/3/4. The real reasons for the RAF’s lukewarm welcome were entirely different, for Fighter Command had asked the wrong people to evaluate the suit. They had asked two squadrons engaged in fighter escort duties at high altitude. There is a world of difference between the ‘g’ protection needed in the high altitude, close escort, of slow American bombers flying in straight lines for four to six hours on end at 25,000 feet, and those engaged in the cut and thrust of medium or low level interceptions and in the business of strafing and rocketting, where high IAS and high ‘g’s are possible for much of the time.
We were far luckier in our contacts with the ‘medical airmen’ in the FAA. We were a fairly close-knit lot and our internal communications were therefore better — even if our test flying was as inept as that of the RAF on occasion. We, in 3 Wing, also had our CO ‘Buster’ Hallet. He talked to the ‘Flying Doc’ at Farnborough and between them they arranged for the suit to be given to us for a job for which it was admirably suited — bombardment spotting. With up to six hours flying a day for a week or more, at high IAS and in continuous steep turns, we should need its protection if we were to last the course. There was never any likelihood that it would be required to prevent blacking out in these turns, of course, for it was not possible to maintain enough ‘g’ in a turn — without diving — in the Seafire/Spitfire (or any other fighter of that time) for more than a few seconds. It would, however, relieve the body from muscular and heart fatigue and it would nullify the effects of up to four ‘g’ for two or three hours a day. It would also enable us to dive and pull away at maximum ‘g’ if we were jumped by Fws or Me 109s, which many of us were, and still see our enemy when he could not see us. The suit must have saved several nasty moments if not complete lives in 3 Wing.
The Americans, whose standard of flying gear was superior to anything which we or the RAF had in WW II, had chosen the air-operated ‘g’ suit. In 1940/41, they used Franks’ Canadian experience and their own results from their full-sized centrifuge, to develop an ‘on demand’ air suit. This used variable pressure air bags instead of water, the pressure of the air supplied being dependent upon the ‘g’ pulled by the pilot. It was much lighter and cooler than the water suit. Franks did not change to an air suit because of the lack of a sufficient supply of air from the small ‘Heywood’ air compressor in the Merlin engine. This compressor supplied the Spitfire/Seafires’ guns and brakes with relatively small quantities of air pumped into a bottle at 600 lbs/sq.in, and it would have been quickly exhausted by a continual requirement for an air suit. However, once jet power was available, with high ‘g’s’, in the Meteor, Vampire, Sea Hawk, etc, the air suit became standard issue for all operational pilots and Observers. Franks’ vision was 20 years into the future.