Although the system might have managed without the radar units, it could never have worked without the Observer Corps. And yet, on days when the enemy formations flew over cloud, this is exactly what it was asked to do. On overcast days, the Observer Corps members could only report the sound of engines somewhere overhead.

Even on clear days it was possible for an RAF and German formation to pass through the same map square without sighting each other. There had never before been a battle in three dimensions, and never a battle moving at such speeds. Yet, for most of the fighting, the coloured counters on the plotting table were no more than four minutes — about fifteen miles — behind events. It proved good enough.

In spite of the totalitarian authority that Göring and Milch wielded ruthlessly, the Luftwaffe had no proper preparations for the Second World War. Not only were there no stockpiles of such vital imports as rubber, aluminium, and magnesium but there were no proper supplies of bombs. And Milch's crash programme to make bombs from concrete was only marginally better than Hitler's crackpot idea about converting them from old gas cylinders.

The Luftwaffe had been organized as a short-range force for short wars in which it would co-operate with an advancing army. The emphasis was upon the bomber and reconnaissance units. Its theory was that the daylight bomber could wipe out the enemy air force by attacking enemy airfields. So there would be no need for night bombers or night fighters. German anti-aircraft guns were excellent and their crews well trained, but the emphasis was upon defending the advancing army and its installations rather than the homeland.

German radar development had put the emphasis upon mobility. There had been no attempt to organize any fighter defence system linked with radar, for it was considered unlikely that Germany would be threatened by sustained air bombardment. The industry of the Ruhr was an exception. It was protected in the way military objectives were. German anti-aircraft resources were suitably concentrated. It was to prove a dangerous place for RAF raiders. For the purpose of command, Germany had been divided into four areas. For each there was an Air Fleet[3], which contained all types of flying units: bombers, dive bombers, fighters, etc. Each Air Fleet was self-contained to the extent of providing its own paratroops, anti-aircraft units, and administration, supply, and legal departments. Such Air Fleets followed the advancing Armies, so that by the time of the Battle of Britain the four districts of the Luftflotten had expanded into Poland and France. Additionally, a new Air Fleet had been created in Norway and Denmark, and the air space over Great Britain had already been divided into Air Fleet areas.

The system of Air Fleets prevented any German airmen from gaining the sort of political power that the 'bomber generals' later enjoyed in both the USAAF and RAF. But, while inhibiting the influence of high commanders, the Luftwaffe gave much greater power and flexibility to its medium-ranking officers.

A Staffelkapitan[4] could be promoted to command a Gruppe, and then become a Kommodore commanding a Geschwader, while continuing to fly. And German flyers had to accept the chances of assignment from bombers to fighters and reconnaissance units. Kesselring himself had been moved from the army to the air force against his wishes!

By the time of the Battle of Britain, the Luftwaffe had modified several aspects of its Air Fleet system. The Fliegerkorps had become more and more specialized. Bombing units employ more men plane for plane than the fighter units do. Perhaps this has something to do with the way the history of air warfare has shown a marked tendency for bombing specialists to dominate High Command decisions. So, in 1940, the voices of the fighter pilots were stifled at Fliegerkorps level. The low importance given to the Luftwaffe fighter arm contributed to the German failure in 1940.

Into the already too complex Luftwaffe command chain was now inserted a Jagdfliegerführer (fighter-aircraft leader). This Jafu had tactical control over all fighter Geschwader in an Air Fleet, and was responsible directly to the Air Fleet commander. It is easy to describe this as a way of concentrating the fighter strength, but the reality was somewhat different. Rather than rely upon the Ge-schwader-kommodore of each fighter and bomber unit to work out details of the fighter escort work, the new Jafu issued directives about formations, radio procedures, flight discipline, and tactics, so as to be sure that the bombers got the co-operation they wanted. The creation of the Jafu (significantly made subordinate to Fliegerkorps for discipline and administration) was certainly not a way of giving more authority to the fighter arm.

It is difficult to compare the opposing air forces. In its simplest terms it was a battle between the RAF which possessed 2,913 aircraft and the whole German Luftwaffe with 4,549 aircraft but such comparisons are misleading. For example, the aircraft of RAF Bomber Command played only an indirect part in the Battle of Britain. Of Coastal Command's squadrons only three came under Fighter Command control to help in the air fighting. The hundreds of RAF transport and liaison aircraft were useful toys for the brass hats but they could not change the Battle's fortunes.

Even within the resources of Fighter Command, one must distinguish between an aircraft classified as 'serviceable' (which means a pilot can sign for it and fly it away) and an aircraft classified as 'available' (which might mean anything from needing a tyre inflated to needing a major overhaul). On 20 July, Dowding had 531 fighters serviceable, out of a total of 609. In reserve he had another 289 fighters.

But while all bureaucracy is devious, military bureaucracy is conspiratorial. And so the effectiveness of the opposing forces cannot be judged by numbers alone. For instance, the RAF measured the efficiency of its squadrons (and its commanders) by the percentage of aircraft that were kept 'serviceable'. So there was a great emphasis, if not to say an obsession, on keeping this figure high. But all aircraft require inspections, checks, and replacements, according to how many hours they fly. So some of the squadrons with the highest percentages of aircraft serviceable had the lowest number of flying hours (a squadron could get 100 per cent aircraft permanently serviceable if it never flew at all).

The 1940 battles forced all the squadrons to maximize their flying hours. In combat, pilots are permitted to use 'panic boost' for a few minutes, which causes immense wear on engines. All this resulted in a dramatic fall in serviceability percentages. Eventually 'serviceability percentages' were seen to be a very misleading indication of efficiency, and squadrons were encouraged to find optimum serviceability percentages instead of maximum ones.

A comparison of aircraft totals is even more misleading when applied to the German air force. It also had a large proportion of transport and liaison aircraft that would play no direct part in the Battle. Neither would the squadrons based in Poland, southern Germany, and Austria nor the single-seat fighters in Norway with not even range enough to get across the North Sea.

The German air force had no reserve of aircraft, in the way that the British did, but the Luftwaffe did draw upon units that were not, at first, engaged in the fighting. The all-important Messerschmitt Bf 109 single-seat fighters were being made at the rate of 140 per month. British industry, newly galvanized by Beaverbrook, were by the time of the Battle turning out Hurricanes and Spitfires at the rate of nearly 500 a month.