The German Air Force also operated throughout the coming battle with low levels of reserves. This was largely a consequence of the poor performance of German aircraft production. Even though Hitler granted special priority in June to the air and naval armaments needed to subdue Britain, the supply of aircraft remained sluggish throughout 1940. Pre-war planning had anticipated a doubling of aircraft production in the first year of war to reach more than 20,000, but these targets were regularly scaled down during 1939 to match factory output. Plan 15, in September 1939, and Plan 16, drawn up only two months later, both reduced planned production in 1940 to little more than 11,000. A new plan was drafted in July 1940, but it offered even lower output for the second half of the year. Some effort was made to give fighter production greater priority, but during 1940 only 1,870 single-engined fighters were produced against a planned output of 2,412. This was less than half the British figure. During the summer and autumn of 1940, output of the Me 109 reached 164 in June, 220 in July, 173 in August and 218 in September, a grand total of 775 against the 1,900 fighters produced in Britain.
There were many causes for the deficiency but complacency was not one of them. Goering pressured and bullied the aircraft industry every bit as much as Beaver-brook. Nor were the resources lacking.
The German aviation industry had access to the most advanced aeronautical technology in the world and enjoyed larger resources of machinery, raw materials and manpower than the British. The answer must be sought elsewhere. The leading culprit was the head of air force procurement, Colonel Ernst Udet. If ever there was a square peg in a round hole, it was Udet. A former First World War fighter ace, he became a well-known stuntman and film-star in the 1920s, and was a noted cartoonist. He gravitated to Goering’s social circle, and was chosen out of the blue to head the air force technical office in 1936, partly because of his popular reputation, partly because Goering wanted a subordinate who posed no threat to his authority. Udet was a ladies’ man and bon viveur, a daring test pilot and man of action, but he was also a political lightweight who found himself utterly out of his depth in a senior bureaucratic post in which long experience and wide technical knowledge were irreplaceable assets. He was manipulated and misled by the businessmen and officials who surrounded him. Later, in 1941, in desperation at his impossible position, he committed suicide, scrawling on the wall of his apartment before he died that Goering had betrayed him to ‘Jews’ in the Air Ministry. His place was taken too late by Field Marshal Erhard Milch, state secretary in the Air Ministry and a former director of Lufthansa, who had been sidelined by Goering in the late 1930s because he threatened to be too competent.
The German Air Force was still a formidable enemy in 1940. It was armed with some of the best combat aircraft then available. The high standard of production and the technical complexity of German aircraft provide at least part of the explanation why Udet found it so difficult to raise the production threshold quickly. In the Messerschmitt Me 109 (also known as the Bf (Bayerische Flugzeugwerke) 109) Germany possessed arguably the world’s best all-round fighter aircraft. The bulk of the force that fought in the battle bore the suffixes E-1 and E-3, variants with improved engine performance introduced during the course of 1939 and 1940. The Me 109E-1 had a top speed of 334 mph at 19,000 feet, and a ceiling of 34,000 feet. It was armed with two 20 mm cannon and two 7.9 mm machine-guns. The cannon provided a less rapid rate of fire than British fighter weapons, but the explosive shells were more effective. In the summer, armour was added to give the pilot enhanced protection. The Me 109E could be out-turned by both the Hurricane and the Spitfire (though whether this was due to the fact that British aircraft used higher-octane aviation fuel remains open to debate); at heights above 20,000 feet, however, the performance gap between the two sides widened considerably in the Messerschmitt’s favour. Because the German fighter’s DB 601 engine had a hydraulic supercharger, which allowed variation of speed with altitude, the Me 109 could fight much more robustly at high altitudes than it could at the lower levels flown by German bombers. If the Battle of Britain had been fought at 30,000 feet, the RAF would have lost it.
The other German aircraft used extensively in the battle were less effective. The second fighter employed was the Messerschmitt Me 110C/110D twin-engined heavy fighter. It could fly further than the Me 109, and had a comparable speed of 336 mph at 19,000 feet, but it proved much less manoeuvrable than the smaller fighters, and its range was much less than expected under combat conditions. The Me 110’s purpose was to lure enemy fighters into battle, allowing the bombers that followed them to fly on to their targets unmolested. In the event the Me 110 had itself to be protected by the Me 109 to prevent insupportable losses. When the Me 110 flew beyond single-seater fighter range, it proved a sitting duck. The British thought that the German Air Force flew a third fighter, the Heinkel He 113, but it proved to be a figment of the imagination. The only aircraft with this designation was a twin-seat dive-bomber developed in 1936, but the model was renumbered the He 118 by its designer because Heinkel feared pilot superstition. The aircraft remained jinxed none the less; when Udet test-flew it himself in June 1936, it broke up in mid-air and he narrowly escaped with his life. The He 118 never saw service. Its mistaken identification in the battle has been attributed to German misinformation.
German bomber aircraft were generally no match for the RAF. The Junkers Ju 87B dive-bomber suffered the same fate as the Me 110. Much slower than the heavy fighter, it was highly vulnerable during bomb attack and was withdrawn early in the battle. The standard twin-engined bombers, the Heinkel 111 and Dornier 17, were early designs and faced obsolescence by 1940. They were slow and poorly armed for combat with high-class fighters; they carried a small bomb-load (around 2,000 pounds maximum), which they could deliver with at least a limited accuracy thanks to a system of radio navigational beams. The newest German bomber, the Junkers Ju 88A-1, could fly further, had a higher speed, and in a dive could not only bomb with greater accuracy, but could outrun a Spitfire. It was produced in small numbers in 1940, and the maximum bomb-load was only 4,000 pounds, about one-fifth of the load carried later in the war by the Avro Lancaster used in the bombing of Germany. Like all German bombers, its defensive armament was weak, and even its extra speed brought it no immunity during daylight operations against the more manoeuvrable and heavily armed British fighters.
The German Air Force also possessed a large complement of highly qualified air crew, with extensive combat experience. Although the single-engined fighter force had fewer pilots than Fighter Command, they survived longer and had a higher rate of operational readiness. Most of the pilots who began the air battle had been trained well before the outbreak of war, though night-flying technique was neglected until the summer of 1940. The average age of German pilots captured in June and July was twenty-six; their average length of service was almost five years. The pilots who engaged in the battle represented the cream of the German Air Force. The training system in 1940 was reformed, like the British system, to try to speed up the throughput of pilots, but standards of training were rigorous. Even if Udet had succeeded in conjuring more aircraft out of German factories, the air force would still have had difficulty supplying the men to fly them.
The task the German Air Force was called on to perform resembled, at least superficially, the opening days of the campaigns against Poland and France when the enemy air force was swiftly neutralized by concentrated bomber and dive-bomber attacks on airfields and support services. A German radio broadcast in early August explained the similarity: ‘the main weapon is the bomb. German bombers will be employed with concentrated effect and in continuous waves. The effect obtained by them has already been shown in such towns as Warsaw, Rotterdam…’ German Air Force records suggest, however, that the fighter was regarded as the principal weapon. The object of the air campaign was to wipe out Fighter Command, using the bombers as bait. ‘Whether the objectives were convoys in the Channel,’ ran a post-war interrogation of German air leaders, ‘or airfields inland, or London, the object was always the same – to bring the defending squadrons to battle to weaken them.’
There was in truth a certain confusion in the instructions issued to the German Air Force in July and early August. On 11 July the three air fleets were issued with an operational directive to begin ‘intensive air warfare against England’, and on 17 July they were ordered to full readiness. Probing attacks began against ports and shipping on the basis of instructions issued earlier in May, but still current, for blockade attacks on British imports. Yet another directive, issued on 16 July for Operation Sealion, ordered further preparations for invasion. Air fleets were expected to attack coastal defences, enemy troop concentrations and reserves, key communication targets and naval installations. The only object they were not yet ordered to destroy was the enemy air force, whose elimination was supposed to be the primary pre-condition for launching an invasion at all. Only in late July did the air force commanders present to Goering their plans for winning air superiority, and not until 1 August did Hitler issue a further directive requiring the air force ‘to overpower the English air force… in the shortest possible time’ through attacks on the whole air force structure and its supporting industries. Once ‘local or temporary air superiority’ was gained, the air force was then expected, without explanation, to switch back to the blockade role it had started with. The knock-out blow against the RAF was set to begin on or shortly after 5 August.
This plethora of orders reflected the deeper uncertainties about the conduct of the war at the highest level. The air force was much clearer in its own mind about the primary objective, and confident of achieving it. On 6 August at Carinhall, his sumptuous country estate outside Berlin, Goering had a final meeting with Kesselring, Sperrle and the commander of Air Fleet 5, General Hans Stumpff. The operational plan they adopted was straightforward: in four days Fighter Command would be destroyed over southern England. The plan was then to move forward systematically sector by sector, destroying military and economic targets up to a line from King’s Lynn to Leicester, until daylight attacks could finally be extended at will over the whole of the British Isles. The initial aim was to send over small forces of bombers with a light escort, leaving the fighter force free to hunt out and destroy enemy fighters. The day for the start of the attack was codenamed Adlertag, day of the eagles.
The precise date for the start of the campaign was more difficult to fix, since success depended critically on a spell of good weather. In Berlin the popular mood worsened at the weeks of apparent inactivity, even when skies were clear. ‘Wonderful weather,’ Goebbels noted acidly. ‘Too good for our air force.’ He detected a certain nervousness in the public: ‘The people fear that we have missed the right moment.’ But in Hitler he observed a real hesitancy to take ‘a damn difficult decision’. The date for attack was finally fixed for 10 August, but bad weather over southern England forced postponement, first to the following day, then to the morning of 13 August. The tension deepened as each day the weather intervened. ‘People wait and wait for the great attack,’ Goebbels noted for 12 August. The following day the weather was indifferent, and attacks were postponed again until the afternoon. By chance, news of the postponement arrived too late for hundreds of aircraft already airborne. They pressed on under poor flying conditions to launch, at only part strength, the long-expected assault. Adlertag began not with a bang, but with a whimper.