Chapter One

Fire

Although the men of the RAF saw their service transformed in the interwar years, their two most deadly enemies never changed: the German Air Force and fire, and for obvious reasons this book focuses on the latter. Fire is the most opportunistic of enemies. It can strike an aircraft at any time, not just in combat, but during take-off and landing, or training or routine non-operational flight. In particular military aircraft, where ammunition so often encounters high octane fuel, make easy, combustible prey.

In any aircraft, fighter or bomber, the fuel tank is the most vulnerable component. This vulnerability had been recognised from the outset of air combat in the Great War – even the earliest aircraft had been able to absorb a surprisingly large amount of ammunition, incendiary or otherwise, but it only took one hit on their tanks to finish them. Fuel tanks could threaten an aircraft in two possible ways: their contents could explode on contact with incendiary ammunition, tearing apart whatever section of the aircraft they were housed in, and in all probability destroying the entire machine; or tanks punctured by ammunition, incendiary or otherwise, could leak fuel into the aircraft which could combust if struck by bullets during combat, or simply drain away the pilot’s ability to fly back to safety.

One Royal Flying Corps observer wrote of what happened when:

‘… the machine to our left was suddenly hit by a shell, full in the main petrol tank! The thing happened so quickly that for a moment I was unable to realise fully what had happened, and remained horror-stricken, watching our companion machine slowly dissolve in the air astern of us.

A second before I had been sitting looking backwards over our tail-plane and regarding what was then evidently a substantial British aeroplane. A fraction of a second later and I saw it hanging in the air before me, its wings floating away from the fuselage whilst a dense black smoke completely obscured the centre section and its occupants. Then, quite slowly, the whole framework twisted sideways, crumpled up, and dived headlong earthwards, wrapped in a sheet of flame.

I sat watching the trail of smoke and fragments which followed it and my companions, down on their two mile journey to the ground and thought many things… it is strange, but at the time I was not so much impressed by the tragic element of the spectacle which I had just witnessed, as by the extraordinary neatness and quickness with which it seemed to have been done. There was something deliberate about it almost suggestive of “legerdemain,” and it was only gradually that I realised the significance of that blank space in the formation following, and the gap at the mess table which would be caused by two stout fellows and comrades of whom fate had robbed us.

I had been actually looking at the machine at the moment of impact, and this, coupled with the fact that the occupants were my friends, left a picture in my memory which I do not often care to revive.’1

RFC pilots were only too well aware of the dangers of fire, nicknaming petrol ‘infernal liquid’, ‘the hell brew’ and ‘orange death’.² Britain’s leading air ace in the Great War, Edward ‘Mick’ Mannock, was obsessed with this form of death, describing to new recruits to his squadron the horrors of ‘flamers’ and how he would shoot himself rather than endure the grisly fate he had arranged for at least six enemy pilots during one month alone in early 1918.³ On hearing of the death of his main rival in the German Imperial Air Service, Manfred von Richthofen, he was heard to say that he hoped the Red Baron had, ‘roasted all the way down’.⁴ One of Mannock’s fellow aces, James McCudden, met just such an end, trapped in his aircraft, but leading American ace Major Raoul Lufbery preferred to take his chances with gravity. After failing to put out a fire by switching off his engine and sideslipping his aircraft (whilst balanced on the head faring so he could keep hold of the joystick), Lufbery finally gave up and leapt from his burning Nieuport aiming hopelessly for a small stream 200 feet beneath him. Horrified onlookers saw his body slam into the ground.5

Pilots continued to dread the effects of fire on both themselves and their aircraft. In 1935 students of the RAF Staff College composed essays on how they saw the future of the air services. The winning entry described how a pilot at ‘Cranwell 1985 AD’ was, ‘injected yesterday with a heavy dose of anti-crash asbestos mixture and… had not quite got over the effects yet.’⁶ Back in the real world, Sholto Douglas, who commanded 43 and 84 Squadrons in France in the First World War and was later Deputy Chief of the Air Staff, recalled in his memoirs how terrifying the threat of fire was to all airmen:

‘On one patrol early in 1917 I was flying formation with my squadron when we were suddenly attacked by some Huns. After the first flurry was over I glanced across at the next aircraft beside me in our formation and I saw that the observer, poor devil, was standing up in the back seat agitatedly trying to call the attention of his pilot to a glint of flame that was just starting to appear along the side of their aircraft. A moment later there was a violent explosion and the whole aircraft disintegrated.

Such a sight was all too common in our flying of those days, and so far as I was concerned it was one of the most horrible that one could witness.’⁷

By 1916 efforts were under way in both the British and French air services to try and reduce such ‘all too common’ horrors. The search for a solution was based on the principle of wrapping the tank in some sort of elasticated material, such as rubber, that would slow incendiary bullets down sufficiently so they would not ignite the contents of the tank. The material would be constituted in such a way so that it could be expected to swell and stretch on impact so as to close or seal any ruptures and prevent leakage, as well as absorb the shock wave caused by the effect of ammunition striking the unit. This system of ‘self-sealing’ fuel tanks became the model for all subsequent investigations into aircraft fuel safety by both Allied and German air services and remains the model today. (As a result of the destruction of Concorde AFR 4590 on 25 July 2000, tanks of the remaining Concorde fleet were given extra self-sealing layers of Kevlar to avoid the danger of their combustion by flying debris.)⁸

In July 1917 the first trials of ‘non-leaking petrol tanks’ were made at the behest of the French Air Service. They had been invented by a Belgian Army engineer, Lanser, and were constructed from a doublehulled metal casing which sandwiched a patented fibrised rubber compound. They had proved successful when the French fired Brock incendiary ammunition at them and had been passed on to the British to undertake similar tests.9

The British Air Board tested two of these ‘Lanser’ tanks the following April but they did not perform to RFC or Admiralty satisfaction. Despite this British reluctance, by 1918 the Lanser tank was standard in the majority of French aeroplanes, and some had even found their way into RFC aircraft, action undertaken unilaterally by British squadron commanders in France (just as some British airmen took to equipping themselves with parachutes in the late summer of 1918, spurred on by the offer of a 20 per cent discount on their life insurance from Lloyds of London if they did so).¹⁰

Dissatisfaction with the performance of the Lanser gave a tremendous momentum to Britain’s own tank protection research, and further momentum was given by the realisation of the possible application of satisfactory measures in airships. Soon Orfordness, the joint forces experimental research station in Suffolk, overflowed with engineers from the Army and Navy blasting away at tanks wrapped in petrol-resisting cloth, tanks with fireproof covers and non-metallic petrol tanks made of plywood and chemically treated fabric. By 1918 all this effort resulted in a tank evolved from the Lanser model with three layers of felt, three of India rubber, soft soap between each, and a cage of iron gauze to resist expansion shock. Known as the M.I.D. pattern, this tank became standard issue in all two-seater aeroplanes (except trainers) from 1918.¹¹

Research into tank safety did not end with the war. The newly independent RAF took over responsibility for a variety of investigations into the problem, and moved the entire programme from Orfordness to the former aircraft factory that had become the Royal Aircraft Establishment (RAE) at Farnborough. Here the relationship between tank safety measures and aircraft design became complicated, as RAF technologies – especially fighter technologies – evolved to meet the very specific strategic demands of a newly-conceptualised air war.

By the mid-1930s it was recognised that the bomber would not necessarily always get through, and that with a combination of ground-based early warning systems and efficient fighter aircraft, deployment of a viable defensive system was possible. This meant that fighters had returned to the heart of British strategic thinking, but in an entirely different form from their predecessors of the Royal Flying Corps. Rather than engage other fighters, the intention of fighter tactics was now to catch and kill large self-defending formations of bomber aircraft. To do this they had to be extremely fast and capable of steep and rapid ascent, as well as carrying the maximum weight possible of armament in order to break up formations of bombers. In contrast to the more gradual evolution of bomber aircraft design, fighter design in the 1930s was completely transformed as wood and fabric biplanes became sleek metal monoplane fighters, the Spitfire and Hurricane.

Much has been written about how the shape of the new fighters determined their speed, but it was just as much about the contents of their fuel tanks. And it was not simply a matter of the switch to high octane fuel, but also of the relationship between the fuel tank contents, the fuel tank locations and the shape of the aircraft. The new fighters were single engined, which gave the requisite acceleration and speed, but they also required one large single fuel storage space in the fuselage. Their compact fuselage shape, part of the aerodynamic styling integral to the speed of the new monoplane fighters, meant that no extra weight could be accommodated at the rear or base of the fuselage. Speed also required that the undercarriage retract inside the airframe during flight, which resulted in the wheels being stored during flight in wing wheel wells. Guns were also mounted in the wings, further reducing the space for fuel storage inside these components. (In the end the Hurricane had half its tank allocation in the wings, but the Spitfire had none.) Wings also played a part in determining the location of the engine parts. Wing chord and span in relation to the fuselage height demanded a heavy front load, especially the Spitfire’s elliptical wing design. This was satisfied by placing the main fuel tanks for both aeroplanes behind the engine in front of the cockpit and pilot. In the case of the Spitfire (before 1942) all the liquid storage was directly in front of the pilot: 48 gallons of high octane fuel in the upper tank, 37 in the lower tank, 5.8 gallons of oil and 15 gallons of glycol coolant. In the case of the Hurricane, the reserve (or gravity) fuel tank of 28 gallons, an oil tank of 7 gallons and the glycol tank of 18 gallons were between cockpit and engine, with a main fuel tank of 25 gallons in each wing.

The fuel itself was key in securing greater speed and lift. Previously using the 87 octane version, both fighters were given a sudden and dramatic power boost by switching their Merlin engines over to high octane fuel early in 1940. The change to a ‘rich mixture response’ 100 octane fuel significantly increased climb rates and engine efficiency. A second innovation was the introduction of constant speed propellers which, in conjunction with the high performance of 100 octane, allowed aircraft to achieve top take-off rates of 3,000 rpm from the moment they left the ground.

In May 1938 Brian Shenstone, chief engineer at Supermarine, made an ostensibly friendly visit to the Messerschmitt aircraft manufacturing works to observe the speed trials of the German aircraft. Although he was not allowed in the factory, he met with Willi Messerschmitt and observed the latest marks of the Messerschmitt 109 and 110 both in flight and on the ground. On returning to Britain, Shenstone went hotfoot to the Air Ministry to report his findings. He told them that Messerschmitt was just as concerned with speed and wing shape as they were at Hawker and Supermarine, but with rather better success, particularly on the speed front. His recommendations regarding the speed trials of the Hurricane and Spitfire were accepted by the technical department of the Air Ministry, who noted:

‘It seems clear [from Shenstone’s report] that is is inadvisable to proceed with a record attempt with the Spitfire. [It has been] suspected for some time that Germany was waiting for us to do so in order to do a better one immediately afterwards.’12

Shenstone’s report to the Air Ministry also demonstrated how thorough was the understanding of the RAF’s offensive capabilities and ambitions throughout British aviation. He helpfully noted that:

‘The B.F.W. [Messerschmitt] factory comprises seven units scattered around the aerodrome, each part complete in itself, including the canteen, so that dislocation due to a direct bomb hit would be a minimum. A guess at the number of workers employed is 5000 to 6000.’¹³

Efforts of men like Shenstone at Supermarine meant that the designs of the new fighters were able to meet all the demands of the RAF strat-egists, but in doing so they also created a new set of problems for the tank safety specialists of the RAE. Nevertheless, despite slow progress in designing sealant systems in the 1920s, by 1936 a full range of tank protection systems had been developed. The principle was the same as that of the Lanser tank model in which the existing metal tank was covered with chemically treated rubber linings. Three different versions of this model were produced which varied the thicknesses of both the metal and rubber components so that by 1938 all British aircraft, regardless of size, model or purpose, could have their petrol tanks sealed, and their crew’s safety made more secure.

There was a very significant ‘but’. Part of the RAE’s testing criteria for the three successful sealant systems was their effect on each aircraft’s performance. For the bombers the sealant systems added as much as 100 pounds to the overall weight of the aircraft but had no measurable effect on their performance. This was not the case for the fighters. Early in 1939 the RAE forwarded its report on tank protection to the Air Ministry, with an appendix that reported the results of tests on fighter sealant systems. The results were incontrovertible and highly problematic.

Reducing the performance of the new fighters by up to one fifth, and therefore compromising their ability to pursue enemy bombers, was never going to be acceptable to the RAF. In November 1939 a meeting was called with the Director of Operational Research (DOR) in the chair which made clear the position on the strategy/safety calculus that the RAE had presented.¹⁵

‘FIGHTERS/SPITFIRE

… if full self-sealing tankage was provided in the Spitfire the loss in fuel would amount to 11 gallons, which was 17% of the total fuel capacity. D.O.R. said that this was a very serious reduction, as the fuel supply at present was no more than adequate. After some discussion it was suggested that an attempt should be made to fireproof the tanks in the same fashion as those of the Messerschmitt. RAE were now investigating this method. It was agreed that there was no acceptable alternative to this. D.O.R. mentioned that the Spitfire was well armoured in front, and its speed made it comparatively immune to attack from astern.

HURRICANE AND DEFIANT

The provision of self-sealing tanks on these aircraft would involve similar large reductions of fuel capacity. It was agreed that they should be dealt with in the same way as the Spitfire.’16

The meeting had opened with a firm statement of the RAF’s commitment to the principle of providing ‘self-sealing protection for 100 per cent of the fuel tanks’ of its aircraft. In practice this meant that 100 per cent of the bomber fleet departing for the defence of France would eventually have full sets of sealed fuel pipes and tanks but that the squadrons of the new fighters which went with them would not.

The decision ultimately to prioritise strategy over safety was reiterated at the highest levels. In December 1939 Wilfrid Freeman (Air Member for Development and Production) responded to a number of enquiries from serving RAF officers about fuel tanks.¹⁷ In a memo Protected Tanks – Summary of Action in Hand, Freeman was frank about the priorities for fighters:

‘New Types

Fighters are, generally speaking, not easy to deal with, as space for fuel tanks is restricted…

Hurricane, Spitfire, Defiant – Present Position:

New tanks of reduced capacity would be required. Air Staff cannot agree to reduction of fuel on these types. Solution is being sought to devise a thin cover, which would render the tanks fireproof.’¹⁸

The RAF’s decision regarding the safety of fighters was not as coldblooded as it might seem at first glance. Not only were RAF leaders firmly convinced that just such a ‘solution’ to the tank issue would be found by the RAE, but it was thought that fighter design and fighter tactics would mitigate the risk until then. Freeman’s memo reminded his audience that pilots were protected ‘against the return fire of bombers by their engines, and by bulletproof glass and armour for their heads and chest respectively’.¹⁹ Furthermore the RAF believed that the form and the tactics of combat in which the fighters would be engaged minimised the risk. They would be attacking self-defending bomber formations from the rear, using their superior rates of speed and climb to assemble into fixed positions behind the bombers. Each fighter would make its attack and then peel away beneath its target, therefore remaining out of range of the German armament for most of the engagement. Not only would these tactics protect them but it was also thought that the invading aircraft suffered from a technological flaw. Hugh Dowding, head of Fighter Command in the Battle of Britain, noted:

‘… at this time the return fire from German bombers was negligible. They had concentrated on performance as [the] principal means of evasion… and the four guns which they carried… were practically useless. Our own fighters… were virtually immune to the fire of unescorted bombers.’20

But the Royal Aircraft Establishment’s engineers and scientists at Farnborough did not allow themselves the luxury of such optimism, and their search for suitable tank protection systems became increasingly desperate as war began to deliver its first aircraft casualties. It was not only the British casualties that caught their attention but also the German ones; from October 1939 any intact enemy aircraft engines and fuel tanks were delivered with due haste to Farnborough for comparison with their British counterparts. In November they got the petrol tank from a Heinkel 111A that had been forced down in the Lammermuir hills.²¹ Tests with 0.303-inch incendiary ammunition (the standard RAF calibre) fired through a sheet of 204 duralumin (a main alloy of aluminium with low density and higher strength to weight ratios) to simulate the aircraft exterior proved that the Germans had a safety system at least as effective as the British version. Bits of a Dornier salvaged from the sea off Wick found their way to Farnborough, as did those from a Junkers 88 which had crashed on the Northumberland coast. An Arado seaplane’s collapsible floating tanks made for an interesting study, as did the Semape-like coverings of an Italian Savoia Marchetti S.82. Indeed, so urgent was the priority for fuel tank safety that Farnborough even gained access to the relevant British intelligence. One such report came from a Dutch rubber manufacturer, Koolhaven, where a Captain von Gijen recommended their flexible tanks for use in Dutch aircraft. Unfortunately his recommendation was made slightly less than two weeks before the German Blitzkrieg overran Holland, and a month before the plant was destroyed by British bombers attacking the aerodrome next door.22 When Farnborough finally got its hands on the nearest equivalent to the British fighters, the Messerschmitt 109, it was found to be of no help to their investigations, and indeed they noted the far worse dangers posed to German pilots by their fuel tanks:

‘… the tank had no self sealing covering. The tank was roughly in the form of a letter “L”. It was fitted in the fuselage directly behind the pilot’s seat but separated from the cockpit by a bulkhead, the foot of the “L” passing under the seat… [bullet] holes would have emptied the tank in a very short time.’²³

So, whilst the RAE searched desperately for the means to secure their greater safety (made worse by increasing shortages of natural rubber), pilots of Spitfires and Hurricanes were to rely upon their tried and tested tactics for countering predicted enemy attacks at the minimum risk to themselves and their aircraft. But the reality of the Battle of France was that it set a pattern that was to be repeated in the Battle of Britain: pilots found themselves engaging the enemy in ways that had far more to do with their Royal Flying Corps predecessors than with the many exercises in which they had practised ‘modern’ air tactics. Bombers did not come in large self-defending formations but with fighter escorts, and fighter squadrons came hunting for other fighter squadrons as part of the overall assault.

Even the RAF’s own handbook took a somewhat optimistic view of the dangers posed to their pilots by fire

The pilots of the RAF found themselves in combat that was complex and chaotic as aircraft used ever higher speeds, and where attacks could come from any angle. Being shot at from all sides meant there was a far greater chance of incendiary ammunition striking the very large fuel reserves at the front of the British fighters. Once again, French skies were full of aircraft fighting, crashing and burning. British fighters were shot down in such alarmingly high numbers, and with so little advantage being gained, that finally the rump was brought home in an effort to preserve some form of defensive force for what was now seen to be the inevitable assault on Britain.

The defence of Britain followed hard on the heels of the fall of France, so quickly, in fact, that there was hardly any time for reflection on the lessons of continental defeat. Wherever possible veterans of the fighting were rushed into training units to impart their experience of the real, rather than conceptualised war in the air. But above all there was no time to understand that there were new human costs to be paid for the war in the air; that realisation would come from the Battle of Britain itself.

There was one one further element of the environment of the inter-war period which had as significant a bearing on the RAF casualty-by-fire as any of the above. What follows is a brief explanation of the medical solution to the problem of wound shock. It may seem worlds away from the bomber and the fighter squadrons but when seen in combination with the strategic and technological background, it is a key component. Put simply, up until the end of the 1930s severe injuries, especially severe burns, killed nearly everyone who suffered them almost immediately. After 1939 they did not. Suddenly there were patients where before there had only been corpses, and those patients often required a complex, exceptional and long-term response to their condition from the relevant medical specialists.

Little has been written about this most fundamental of medical breakthroughs, perhaps because the process lacks the drama and instant success stories of developments such as penicillin treatment or vaccination. Instead, throughout the 1930s a series of low-level, incremental improvements were made, not in well-funded laboratories or high-profile teaching hospitals, but in emergency rooms and ordinary hospitals where doctors slowly but surely pushed back the limits of existing clinical understanding of the processes involved in the human body’s initial reaction – shock – to its severe wounding.

For the burn victim, shock takes a particularly virulent form. The body loses catastrophically high amounts of liquid at the site of the burn, and goes into secondary shock as the rest of the system attempts to compensate for this loss by shifting fluid around the various organs of the body in an attempt to keep each one viable. One by one kidneys, liver and finally the brain are compromised by the loss of liquids and proteins and within 24 hours the patient literally dies of dehydration and starvation. Failure to understand and compensate for this fluid shift meant that, to take a typical example, in the Glasgow Royal Infirmary burns ward in 1937, half of the serious burns patients were dead in 24 hours and three-quarters within three days. And if patients managed by some twist of fate to survive burn shock, they were then almost certainly done for by infection. The reality for burn casualties in the inter-war period was that seriously injured patients were given a little saline, a large dose of morphine and then taken home to die. Without adequate means to address the systemic catastrophe caused by a serious burn, it was no wonder that the burned patient was always regarded as terminal, and furthermore, ‘in the early years the over-30% burn was rarely admitted to a teaching hospital, for the case was virtually hopeless and certainly a danger to others.’24

In the 1920s doctors had begun giving shocked patients small transfusions of saline in an attempt to counteract fluid shift, but fears about side effects meant it was never given in sufficient amounts to make any real difference. More often than not the result was simply to prolong the inevitable by a couple of days, but an important precedent – of transfusion therapy being used to treat fluid shift – had been established.

The 1930s saw the most significant breakthroughs in the treatment of burn shock as doctors began to explore the full range of uses of plasma (the universally compatible liquid medium that transports blood and proteins through the body). Saline and plasma were combined to produce a new range of transfusion therapies that could not only replace the lost fluid in the system, but also the proteins that are lost with it. Once again, an important precedent was set, but this time clinicians did not hold back in their efforts to understand the full potential of such therapies. Transfusions were given in increasingly high amounts, several times a day, and with their effects closely and carefully monitored by nursing staff:

‘… staff developed a complex system of calculations that matched the size and depth of the wound trauma site with the fluid shift it would generate and the requisite amount of transfused plasma and saline.’25

Fewer and fewer patients died of their injuries and by the outbreak of war this most significant of clinical breakthroughs had, almost imperceptibly but just in time, become an accepted part of emergency medicine.

If confirmation was needed that modern medicine had found the solution to secondary wound shock, no-one would have had to look any further than the RAF hospitals in the summer of 1940. Here lay men, first a few from the Battle of France, and then in greater numbers from the Battle of Britain, who should have died from their injuries but did not. What had at first seemed a straightforward strategy/safety calculus for the RAF in regard to its fighters had become complicated not only by the realities of combat but also by contemporary medical developments. These developments presented the RAF and its medical service with living, human consequences of decisions made in the inter-war period. For the RAF this was an immediate emergency, not only for the valuable pilots suffering the injury, but for the service itself in compensating for their loss, correcting its causes and caring for the air war’s unforeseen human consequences.