First-line aircraft based in Great Britain had increased from 564 aircraft to nearly 1,500; and those of the Air Forces overseas from 168 aircraft to about 450. Between 1934 and 1939, therefore, the front-line strength had been raised by about 165%. Great changes had also taken place in the equipment of the

Service. When I left England, the Royal Air Force was equipped with wooden biplanes fitted with fixed undercarriages, constant-pitch airscrews and open cockpits; when I arrived home five years later, it was equipped with low-wing, metal-constructed monoplanes, retractable undercarriages, variable-pitch airscrews, landing flaps, enclosed cockpits, higher performance engines and many other new devices, bringing about a tremendous advance in aircraft performance.

In 1934 the highest-performance fighter was the Fury II with a top speed of 220 miles an hour and capable of climbing to 20,000 feet. In 1939 the Hurricane I had a top speed of over 300 miles an hour and could climb to 30,000 feet, while the Spitfire I had a speed of over 350 miles an hour and an operating height of 33,000 feet. The Fury carried only two Vickers -303 machine-guns, relics of the 1914-18 war, whereas both Hurricanes and Spitfires carried eight -303 Browning guns, which had a higher rate of fire and greater reliability than the Vickers machine-gun.

There is little doubt that the weakest point of our bomber force at this moment lies in its gun defence. I fear that the standard of efficiency of air gunners and their ability to resist hostile attack remains extremely low.

We have all this valuable equipment and highly trained personnel depending for its safety upon one inadequately trained and inexperienced individual, generally equipped with a single relatively inadequate gun in a very exposed position in the tail of the aircraft. Here he has to face the full blast of the eight-gun battery of the modern fighter. The demands which will be made on the coolness, presence of mind, skill and efficiency of this single individual are, in existing conditions, almost superhuman, and in his present state of knowledge and training it is utterly fantastic to expect the efficient defence of the aircraft.

As things are at present, the gunners have no real confidence in their ability to use this equipment efficiently in war, and captains and crews have, I fear, little confidence in the ability of the gunners to defend them against destruction by enemy aircraft.

I would remind the Air Council that the last estimate which they made as to the force necessary to defend this country was fifty-two squadrons, and my strength has now been reduced to the equivalent of thirty-six squadrons.

I must therefore request that as a matter of paramount urgency the Air Ministry will consider and decide what level of strength is to be left to the Fighter Command for the defence of this country, and will assure me that when the level has been reached, not one fighter will be sent across the Channel however urgent and insistent the appeals for help may be.

I believe that if an adequate fighter force is kept in this country, if the Fleet remains in being, and if Home Forces are suitably organized to resist invasion, we should be able to carry on the war single-handed for some time, if not indefinitely. But, if the Home Defence Force is drained away in desperate attempts to remedy the situation in France, defeat in France will involve the final, complete and irremediable defeat of this country.

The great Dunkirk evacuation started on 26th May. The RAF was extremely active throughout the famous withdrawal but such is the nature of aerial combat that the skirmishes seldom occurred in sight of the actual evacuation beaches.

In the thick of it at this time was Al Deere - destined to be shot down seven times and survive the war with a magnificent record. Like most others, this great fighter pilot from New Zealand had sat in a Spitfire for the first time earlier in 1940 and said: "A Spitfire is the most beautiful and easy aircraft to fly and has no tricks or peculiarities normally attributable to high-speed fighters.

He was shot down twice in two days at Dunkirk. Typically, he said the first time gave him "little trouble". The second must be recorded.

During a patrol over the evacuation beaches his Spitfire was hit in the glycol tank. This was always fatal to the aeroplane since the coolant drained and the engine overheated and seized in a matter of seconds rather than minutes. Al Deere crash-landed his Spitfire on the beach knocking himself out in the process. When he came round a minute or two later, he was aware of the engine smoking menacingly. Urgently, he ripped off his straps, leapt out of the cockpit, and sat down on the beach. At the moment he could only curse his bad luck rather than appreciate his good luck at being alive.

Including ground-strafing, dive bombing and air-to-air fights, I had probably by now killed several hundred people, but from the air it was completely impersonal, and made no mental impact. This man was different.

I was out alone on another "cannon test", which was the usual thinly veiled excuse to look for trouble. None of the aircraft in the air had the slightest smell of the Luftwaffe, so I confined my searchings to objects on the ground many miles behind the enemy front. Suddenly I saw him!

His motorbike had caused a small cloud of dust to arise, giving away his position. Like a Kestrel hawk pouncing, I wheeled my Spitfire and streaked towards the ground.

By now my man had stopped on the corner of a hairpin bend, and as the range closed rapidly, I guessed he was studying a map. His military camouflaged bike and his grey-green uniform spelt him out as a dispatch rider, and therefore a legitimate military target. As I placed the orange reflected dot of my gunsight on the centre of his body, he looked up straight at me, and knew the moment of truth had arrived.

As I stabbed the gun button he threw up his left arm as if to shield his face from the impact. I cursed him with all my soul for making such a simple pathetic human gesture, and loathed myself as I saw a man and bike disappear in a torrent of bullets.

I returned straight to base, and found it difficult to talk to anyone for several days.

I can still see his face and the raised arm.

It is fascinating to watch the reactions of the various pilots. They fall into two broad categories; those who are going out to shoot and those who secretly and desperately know they will be shot at, the hunters and the hunted. The majority of the pilots, once they have seen their name on the board, walk out to their Spitfires for a pre-flight check and for a word or two with their ground crews. They tie on their mae-wests, check their maps, study the weather forecast and have a last-minute chat with their leaders or wingmen. These are the hunters.

The hunted, that very small minority (although every squadron usually possessed at least one), turned to their escape kits and made quite sure that they were wearing the tunic with the silk maps sewn into a secret hiding-place; that they had at least one oilskin-covered packet of French francs, and two if possible; that they had a compass and a revolver and sometimes specially made clothes to assist their activities once they were shot down. When they went through these agonized preparations they reminded me of aged countrywomen meticulously checking their shopping- lists before catching the bus for the market town.

The loss of seven Blenheims out of seventeen in the daylight attack on merchant shipping and docks at Rotterdam is more severe. Such losses seem disproportionate to an attack on merchant shipping not engaged in vital supply work. The losses in our bombers have been very heavy this month, and Bomber Command is not expanding as was hoped. While I greatly admire the bravery of the pilots, I do not want them pressed too hard.

It is very disputable whether bombing by itself will be a decisive factor in the present war. On the contrary, all that we have learnt since the war began shows that its effects, both physical and moral, are greatly exaggerated. There is no doubt that British people have been stimulated and strengthened by the attack made upon them so far. Secondly, it seems very likely that the ground defences and night-fighters will overtake the air attack. Thirdly, in calculating the number of bombers necessary to achieve hypothetical and indefinite tasks, it should be noted that only a quarter of our bombs hit the targets. Consequently an increase of bombing to 100 per cent would in fact raise our bombing force to four times its strength. The most we can say is that it will be a heavy and I trust a seriously increasing annoyance.

We made our preparations for the thousand bomber attack during May; it had the code word "Millenium".

The organisation of the force involved a tremendous amount of work throughout the Command. The training units put up 366 aircraft. No. 3 Group, with its conversion units put up about 250 aircraft, which was at that time regarded as a strong force in itself. Apart from four aircraft of Flying Training Command, the whole force of 1047 aircraft was provided by Bomber Command.

The moon was full on the night of May 30th and that morning we were promised good weather over the home bases. On the other hand thundery cloud was known to cover much of Germany; the weather often helped the enemy throughout the war, and at this time it was much to his advantage that the winds which brought good weather over our bases tended to produce cloud over Germany. If I sent the force that night, the target might be cloud-covered, and the whole operation reduced to naught and our plan disclosed. From among a number of suitable targets only Cologne was at all likely to have reasonably good weather during the night, and there was no certainty about the weather over Cologne. I chose Cologne and dispatched the force.

Nearly 900 aircraft attacked out of the total of 1047, and within an hour and a half dropped 1455 tons of bombs, two-thirds of the whole load being incendiaries. The casualty rate was 3.3 per cent, with 39 aircraft missing, and, in spite of the fact that a large part of the force consisted of semi-trained crews and that many more fighters were airborne than usual, this was considerably less than the average 4.6 per cent for operations in similar weather during the previous twelve months. The medium bomber had a casualty rate of 4.5 per cent, which was remarkable, but it was still more remarkable that we lost scarcely any of the 300 heavy bombers that took part in this operation; the casualty rate for the heavies was only 1.9 per cent. These had attacked after the medium bombers, when the defences had been to some extent beaten down, and in greater concentration than was possible for the new crews in the medium bombers. The figures proved conclusively that the enemy's fighters and flak had been effectively saturated; an analysis of all reports on the attack showed that the enemy's radar location devices had been able to pick up single aircraft and follow them throughout the attack, but that the guns had been unable to engage more than a small proportion of the large concentration of aircraft.

Reconnaissance after the attack showed that 600 acres of Cologne had been devastated and this in turn conclusively proved that the passive defences of Cologne had been saturated In just the same way as its guns and searchlights had been, together with the air defence of the whole of Western Germany, by concentration of attack. The damage had increased out of all proportion to the increase of bomb tonnage.

We in Britain know quite enough about air raids. For ten months your Luftwaffe bombed us. First you bombed us by day. When we made this impossible, they came by night. Then you had a big fleet of bombers. Your airmen fought well. They bombed London for ninety-two nights running. They made heavy raids on Coventry, Plymouth, Liverpool, and other British cities. They did a lot of damage. Forty-three thousand British men, women and children lost their lives; Many of our most cherished historical buildings were destroyed.

You thought, and Goering promised you, that you would be safe from bombs. And indeed, during all that time we could only send over a small number of aircraft in return. But now it is just the other way. Now you send only a few aircraft against us. And we are bombing Germany heavily.

Why are we doing so? It is not revenge-though we do not forget Warsaw, Belgrade, Rotterdam, London, Plymouth and Coventry. We are bombing Germany, city by city, and even more terribly, in order to make it impossible for you to go on with the war. That is our object. We shall pursue it remorselessly. City by city; Liibeck, Rostock, Cologne, Emden, Bremen; Wilhelmshaven, Duisburg, Hamburg - and the list will grow longer and longer. Let the Nazis drag you down to disaster with them if you will. That is for you to decide.

In fine weather we bomb you by night. Already 1000 bombers go to one town, like Cologne, and destroy a third of it in an hour's bombing. We know; we have the photographs. In cloudy weather we bomb your factories and shipyards by day. We have done that as far away as Danzig. We are coming by day and by night. No part of the Reich is safe.

I will speak frankly about whether we bomb single military targets or whole cities. Obviously we prefer to hit factories, shipyards, and railways. It damages Hitler's war machine most. But those people who work in these plants live close to them. Therefore, we hit your houses and you. We regret the necessity for this. The workers of the Humboldt-Deutz, the Diesel-engine plant in Cologne, for instance-some of whom were killed on the night of May 30 last-must inevitably take the risk of war. Just as our merchant seamen who man ships which the U-boats (equipped with Humboldt-Deutz engines) would have tried to torpedo. Were not the aircraft workers, their wives and children, at Coventry just as much 'civilians' as the aircraft workers at Rostock and their families? But Hitler wanted it that way.

It is true that your defences inflict losses on our bombers. Your leaders try to comfort you by 'telling you that our losses are so heavy that we shall not be able to go on bombing you very much longer. Whoever believes that will be bitterly disappointed. I, who command the British bombers, will tell you what our losses are. Less than 5 per cent of the bombers which we send over Germany are lost. Such a percentage does very little even to check the constant increase ensured by the ever-increasing output of our own and the American factories.

America has only just entered the fight in Europe. The squadrons, forerunners of a whole air fleet, have arrived in England from the United States of America. Do you realize what it will mean to you when they bomb Germany also? In one American factory alone, the new Ford plant at Willow Run, Detroit, they are already turning out one four-engined bomber able to carry four tons of bombs to any part of the Reich every two hours. There are scores of other such factories in the United States of America. You cannot bomb those factories. Your submarines cannot even try to prevent those Atlantic bombers from getting here; for they fly across the Atlantic.

Soon we shall be coming every night and every day, rain, blow or snow-we and the Americans. I have just spent eight months in America, so I know exactly what is coming. We are going to scourge the Third Reich from end to end, if you make it necessary for us to do so. You cannot stop it, and you know it.

You have no chance. You could not defeat us in 1940, when we were almost unarmed and stood alone. Your leaders were crazy to attack Russia as well as America (but then your leaders are crazy; the whole world thinks so except Italy).

How can you hope to win now that we are getting even stronger, having both Russia and America as allies, while you are getting more and more exhausted ?

Remember this: no matter how far your armies march they can never get to England. They could not get here when we were unarmed. Whatever their victories, you will still have to settle the air war with us and America. You can never win that. But we are doing so already now.

One final thing: it is up to you to end the war and the bombing. You can overthrow the Nazis and make peace. It is not true that we plan a peace of revenge. That is a German propaganda lie. But we shall certainly make it impossible for any German Government to start a total war again. And is not that as necessary in your own interests as in ours?

On two days of this week, two air raids, far greater in scale than anything yet seen in the history of the world, have been made on Germany. On the night of the 30th May over a thousand planes raided Cologne, and on the night of the 1st June, over a thousand planes raided Essen, in the Ruhr district. These have since been followed up by two further raids, also on a big scale, though not quite so big as the first two. To realise the significance of these figures, one has got to remember the scale of the air raids made hitherto. During the autumn and winter of 1940, Britain suffered a long series of raids which at that time were quite unprecedented. Tremendous havoc was worked on London, Coventry, Bristol and various other English cities. Nevertheless, there is no reason to think that in even the biggest of these raids more than 500 planes took part. In addition, the big bombers now being used by the RAF carry a far heavier load of bombs than anything that could be managed two years ago. In sum, the amount of bombs dropped on either Cologne or Essen would be quite three times as much as the Germans ever dropped in any one of their heaviest raids on Britain. (Censored: We in this country know what destruction those raids accomplished and have therefore some picture of what has happened in Germany.) Two days after the Cologne raid, the British reconnaissance planes were sent over as usual to take photographs of the damage which the bombers had done, but even after that period, were unable to get any photographs because of the pall of smoke which still hung over the city. It should be noticed that these 1000-plane raids were carried out solely by the RAF with planes manufactured in Britain. Later in the year, when the American airforce begins to take a hand, it is believed that it will be possible to carry out raids with as many as 2,000 planes at a time. One German city after another will be attacked in this manner. These attacks, however, are not wanton and are not delivered against the civilian population, although non-combatants are inevitably killed in them.

Cologne was attacked because it is a great railway junction in which the main German railroads cross each other and also an important manufacturing centre. Essen was attacked because it is the centre of the German armaments industry and contains the huge factories of Krupp, supposed to be the largest armaments works in the world. In 1940, when the Germans were bombing Britain, they did not expect retaliation on a very heavy scale, and therefore were not afraid to boast in their propaganda about the slaughter of civilians which they were bringing about and the terror which their raids aroused. Now, when the tables are turned, they are beginning to cry out against the whole business of aerial bombing, which they declare to be both cruel and useless. The people of this country are not revengeful, but they remember what happened to themselves two years ago, and they remember how the Germans talked when they thought themselves safe from retaliation. That they did think themselves safe there can be little doubt. Here, for example, are some extracts from the speeches of Marshal Goering, the Chief of the German Air Force. "I have personally looked into the air-raid defences of the Ruhr. No bombing planes could get there. Not as much as a single bomb could be dropped from an enemy plane', August 9th, 1939. "No hostile aircraft can penetrate the defences of the German air force", September 7th, 1939. Many similar statements by the German leaders could be quoted.

As this will only be read after my death it may seem a somewhat macabre document, but I do not want you to look on it in that way. I have always had a feeling that our stay on earth, that thing we call 'Life', is but a transitory stage in our development and that the dreaded monosyllable 'Death' ought not to indicate anything to be feared. I have had my fling and must now pass on to the next stage the consummation of all earthly experiences.

You know I hated the idea of war, and that hate will remain with me forever What has kept me going is the spiritual force to be derived from music, its reflection in my own feelings, and the power it has to uplift a soul above earthly things Mark has the same experience as I have, though his medium of encouragement is poetry. Now I am off to the source of music and can fulfil the vague longing of my soul in the becoming part of the fountain whence all good comes. I have no belief in an omnipresent God, but I do believe most strongly in a spiritual force which was the source of our being, and which will be our ultimate good. If there is anything worth fighting for, it is the right to follow on our own paths to this good, and to prevent our children from having their souls sterilised by Nazi doctrines. The most terrible aspects of Nazism is its system of education, of driving in instead of leading out, and putting the state above all things spiritual. And so I have been fighting.

"A" was to build up the resources necessary to get a decision by invasion before German industry and economic power had been broken;

"B" was to shatter German resistance by air and then put in the Army;

"C" was a compromise under which we tried to build up simultaneously strong land and air forces on a scale unrelated to any particular task, without any clear intention of attaining a definite object by a definite time.

For his part, he favoured course "B", for which he thought a combined heavy bomber force rising to a peak of between four and six thousand might be necessary.

It is difficult to estimate the moral consequences of a scale of bombardment which would far transcend anything within human experience. But I have no doubt whatever that against a background of growing casualties, increasing privations and dying hopes it would be profound indeed.

I am convinced that an Anglo-American bomber force based in the United Kingdom and building up to a peak of 4,000-6,000 heavy bombers by 1944 would be capable of reducing the German war potential well below the level at which an Anglo-American invasion of the Continent would become practicable. Indeed, I see every reason to hope that this result would be achieved well before the combined force had built up to peak strength.

Bomber Command: first tour, 30 sorties; second tour, not more than 20 sorties.

Pathfinder Force: a single continuous tour of 45 sorties.

Fighter Command: Day Fighters, normal maximum 200 hours. Night Fighters, 100 hours or a maximum of 18 months.

Coastal Command: Flying boats and four-engined land-plane crews, 800 hours. Photographic Reconnaissance squadrons, 300 hours. Fighter, torpedo and other squadrons employed offensively, 200 hours.

One school of thought recommends crossing the Channel low down to approach the enemy coast below the (radar) screen. I am opposed to this, because of the danger of flak from the Royal Navy and from enemy convoys, besides which a heavily laden aeroplane will not climb very quickly to the height at which it is safest to cross the enemy coast.

It is generally safer to cross the enemy coast as high as possible up to 8,000 feet. This gives you a general view of the lie of the coast and avoids the danger of light flak and machine-gun fire which you might meet lower down. On the other hand, your pinpoint at the coast is of vital importance, for by it you gauge your wind and set your course for the interior along a safe route, so it may be necessary to fly along a much lower route than 8,000 feet to see where you are in bad weather. Don't think that you will be safe off a flak area within four miles. I have been shot at fairly accurately by low angle heavy flak three miles off Dieppe at 2,000 feet, so, until you know where you are, it is not wise to make too close an investigation of the coast-line. In this case you may identify the coast by flying parallel with it some miles out to sea. Notice the course which it follows and any general changes of direction which it takes. By applying these to your map you will generally find that you must be at least on a certain length of coastline and, at best at a definite point. When you know your position you may gaily climb above any low cloud there may be and strike into the interior on Dead Reckoning.

I had taken over 77 Squadron (in December, 1941) from an ex-civil pilot called Young. The few days in which he handed over to me were most valuable, as he was an experienced pilot and a good one. He gave me the "gen" on the bombing game as thoroughly as he could in that time, and it was a fairly colourful picture which he painted! My first main job in commanding 77 was to tighten up on navigation. Such things as compass swings in the air had never been heard of, and general precision was fairly low. When I arrived, night photography was regarded as a rarity, and there was little proof of what results had been achieved. Bomb aiming was done in those days by the navigator, and was generally of a fairly high order. One fact soon became apparent, however, from interrogation after raids - the angle of bombing considered to be normal by bomb aimers was related to the low level practices which they had done, and not to the height in which they normally operated at night. I had a blitz on this point thereafter, and managed to make people appreciate the fact that the bomb angle was in fact very dose to the vertical at anything like operational height.

The results of my navigational efforts soon began to be reflected in our bombing results. We took more and more successful night photos, and all of them proved that we were getting to our target In fact, I used particularly to have any crew "on the mat" who failed to get photos. When I arrived at the Squadron it was a matter of considerable pride if a crew brought home a photo showing the target area at all, but it soon became a matter of considerable disgrace if one failed to obtain a photo of the aiming point itself.

The casualty rate at that time was running around 4 to 5 per cent. per raid, and as the normal tour of operations was thirty raids, anybody with a reasonable mathematical training could calculate the risk of survival. Those with more varied mathematical outlooks, however, achieved all sorts of ideas as to what the possibilities might be. Our crews were, in any case, comforted by the knowledge expressed by the Intelligence Officer on each station that at least three out of four crews shot down were made prisoners of war and were not lost completely. The proportions were in-reality not quite as favourable as this - but more nearly the reciprocal.

The bombing of friendly towns during the campaign, and the insistence by the Army Commanders that it was a military necessity caused me more personal worry and sorrow than I can say. My resistance, apart from humanitarian grounds, was due to a conviction, since confirmed that in most cases we were harming Allies and ourselves eventually more than the enemy. I thought, also, of the good name of our forces, and particularly of the Air Force. It is a sad fact that the Air Forces will get practically all blame for destruction which, in almost every case, was due to Army demands. On many occasions, owing to the organization of command, I was over-ruled and then came the "blotting" by strategic bombers who, on their experience with German targets, tended to over hit. Ample factual evidence will now be forthcoming, and I hope that, in future, it will not be thought that the sight and sound of bombers, and their uplift effect on morale, is proportional to the damage they do to the enemy.

I do not myself believe that any modern war can be won either at sea or on the land alone or in the air alone. In other words, war has changed to three dimensional, and very few people realise that.

The real importance of the air war consisted in the fact that it opened a second front before the invasion of Europe. The front was the skies over Germany. Every square metre of the territory we controlled was a kind of front line. Defence against air attacks required the production of thousands of anti-aircraft guns, the stockpiling of tremendous quantities of ammunition over the country, and holding in readiness hundreds of thousands of soldiers, who in addition had to stay in position by their guns, often totally inactive, for months at a time.

I soon came to the conclusion that the policy of area bombing of Germany, then being pursued mainly by Wellington bombers, was not paying off, because the expenditure of our resources and, still more, of our skilled manpower, was far greater than the results achieved. Too many of our bombs were dropped in fields. German arms production was not being seriously interfered with. The best that could be said for it was that a considerable number of Goering's fighter aircraft, which might have been sent to other fronts, had to be kept in Germany. The truth is that in those days the instruments for accurate navigation did not exist. There were high hopes of one gadget, which I did not begin to understand; and which was brought to us one day in a brand-new Wellington bomber. All the navigators in the squadron went up to see how it worked. Five minutes after take-off, a wing fell off the plane, and they were all killed.

Early in 1942, Lindemann, by then a member of the Cabinet, circulated his famous paper on strategic bombing. This said that if it was concentrated entirely on German working class houses, and 'military objectives' as such were forgotten, it would be possible to destroy fifty per cent of all the houses in the larger towns of Germany quite soon. Charming! The paper was strongly opposed by the scientists, headed by Sir Henry Tizard and Professor Blackett. Tizard calculated that Lindemann's estimate was five times too high, and Blackett that it was six times too high. But Lindemann was Churchill's man; and Lindemann prevailed. After the war the bombing survey revealed that his estimate was ten times too high.

The story of the Lindemann-Tizard controversy has been well told by C. P. Snow in his book Science and Government; and I have not seen it seriously contradicted. But one thing remains to be said. I think the scientists underestimated the psychological effect of our bombing policy not upon the German but upon the British people. They themselves were under heavy bombardment; and between 1941 and 1944 bombing was the only method by which we could directly hit back. I am sure that it gave a tremendous boost to British morale; and that, to this extent at least, the thousands of brave and skilled young men in Bomber Command did not give their lives in vain.

The great immorality open to us in 1940 and 1941 was to lose the war against Hitler's Germany. To have abandoned the only means of direct attack which we had at our disposal would have been a long step in that direction.