TheGreatest Air Battle in History up to That Time
On 10 May 1940, Germany invaded France and the Low Countries. The British and French armies were rapidly defeated; 333,000 men ultimately escaped via Dunkirk, but they abandoned most of their heavy equipment. During the fighting, insistent appeals for reinforcement came from France, and Dowding famously appeared before the War Cabinet on 15 May to plead that no more Hurricanes be deployed across the Channel; he repeated his plea in a letter the next day. By that time, the Chief of the Air Staff, Air Chief Marshal Sir Cyril Newall, had also concluded that no useful purpose would be served by further reinforcement. As he put it, he did not believe “a few more squadrons whose loss might vitally weaken the fighter line at home, would make the difference between defeat and victory in France.” Newall’s support for Dowding was crucial. As it was, the losses incurred during the fighting in France and over Dunkirk were heavy, amounting to nearly 400 Hurricanes and 67 Spitfires; 280 pilots were killed and 60 wounded.
The stage was now set for the greatest air battle in history up to that time. Fighter Command, under Sir Hugh Dowding, had four subordinate fighter groups. The most important was 11 Group, with its headquarters at Uxbridge, commanded by the New Zealander, Air Vice-Marshal Keith Park. Park had eighteen squadrons of Hurricanes and Spitfires with another forming. Further north, covering East Anglia and the industrial Midlands, was 12 Group, under Air-Vice Marshal Trafford Leigh-Mallory, with its headquarters at Watnall near Nottingham. At the start of the Battle, Leigh-Mallory had ten squadrons of Hurricanes and Spitfires with one more forming. To the West was 10 Group, under the command of a South African, Air Vice-Marshal Sir Quintin Brand, headquartered at Rudloe Manor in Wiltshire. The Group initially comprised four squadrons of Hurricanes and Spitfires, though another two were forming. The north of England and Scotland was the responsibility of 13 Group, which also had ten squadrons of Hurricanes and Spitfires with a further four in the process of forming.
Dowding therefore possessed some 42 Hurricane and Spitfire squadrons along with six squadrons of twin-engined Bristol Blenheims and two squadrons of Boulton Paul Defiants. The poor performance of these latter aircraft soon caused them to be relegated to the night-fighter role. These fifty squadrons had 656 serviceable aircraft available at 9 o’clock on the morning of 10 July 1940, the date on which Dowding considered that the Battle of Britain began. Of these, 226 were Spitfires and 344 Hurricanes.
Meanwhile, the Luftwaffe was massing on the other side of the English Channel. The German victory in France and in the earlier campaigns in Denmark and Norway had greatly complicated Dowding’s defensive task. The Germans were now ensconced on airfields in a broad arc stretching from the Contentin peninsula of Normandy, some sixty miles to the south of the Isle of Wight, round through Northern France and the Pas de Calais, through Holland and Belgium, and on northwards into Denmark and Norway. In theory, they could attack from all these directions. However, the main axis of threat came from France and the Low Countries; only once during the Battle did the German air fleet in Scandinavia (Luftflotte 5) attempt to intervene. Even so, the possibility of attack from that area could not be ignored, and Dowding had to position his squadrons to meet the threat from all these countries. Moreover, the combined forces of the two major German air fleets across the Channel, Luftflotten 2 and 3, were quite formidable enough. On 20July, they disposed of the following strengths:
Twin-engined bombers, 1131 769
Dive-bombers 316 248
Single-engined fighters 809 656
Twin-engined fighters 246 168
Long-range reconnaissance 67 48
Luftflotte 5 had a further 211 aircraft, of which 160 were serviceable. On that day, Dowding had 532 Hurricanes and Spitfires serviceable and 336 of these were in 11 Group. The critical comparison is between this figure and the 656 serviceable Messerschmitt 109 single-engined German fighters. The disparity is not great but the Germans had the singular advantage of choosing where and when they would strike, whilst Dowding had to spread his forces to cover the entire nation. The Germans therefore generally had an advantage in numbers when combat was joined.
One of the curiosities of the Battle is that, while the British date its beginning as 10 July, the Germans do not believe it started until August! The reason for this slight divergence in perspective is simply that the July air battles were largely confined to daylight confrontations over the English Channel, where the Luftwaffe mounted attacks on coastal convoys and ports, combined with nuisance night raids by single aircraft on targets across the country. The Germans called this the Kanalkampf (literally Channel Battle). Between 10 July and 7August, they mounted attacks against convoys involving nine bombers or more on eleven days, and there were seventeen further attacks by single aircraft or small formations. Fighter escorts were present for all the larger attacks and Fighter Command squadrons were thus drawn into battle to protect the ships, often on disadvantageous terms. In this period, Dowding lost 74 pilots killed or missing and 48 wounded, and this constant drain on his resources was a cause for concern even though his pilot strength was gradually increasing.
During the second half of July and early August, the Luftwaffe prepared for the much greater battles to come. Their plan envisaged a large-scale aerial assault on the UK beginning on 13 August – Adler Tag or Eagle Day – preceded by a series of attacks against Fighter Command’s south coast radar chain and coastal airfields on the 12th. Five radar stations were attacked and some went off the air for a time, although others continued to operate. But the station at Ventnor on the Isle of Wight was destroyed and the resulting “hole” in the radar chain was only partially filled when a mobile transmitter arrived on 15 August and a new station opened at Bembridge on the 23rd. Attacks were also delivered against Lympne, Manston and Hawkinge airfields. The Germans did not escape unscathed, however, with thirteen of 11 Group's eighteen squadrons in action and Fighter Command flying over 500 sorties and claiming 57 kills. In fact, the Germans lost some 30 aircraft in combat with a number also badly damaged.
The next day, Adler Tag,got off to an inauspicious start when German bomber formations and their escorts took off in the early morning but were recalled by none other than the commander of the Luftwaffe, Reichsmarshall Herman Goering himself. The radio message was not received by all the units involved, and a bomber formation continued on towards its targets in Kent whilst its fighter escort turned back. Several bombers were shot down. Further west, the reverse happened: the bombers turned back, while their escort of Messerschmitt 110 twin-engined fighters carried on with the planned attack on Portsmouth. They were intercepted by two RAF squadrons, which shot down six in as many minutes. Similarly, a formation of Stuka dive-bombers tasked to attack Middle Wallop was caught by Spitfires and lost six out of nine aircraft. Airfields at Detling and Eastchurch were bombed, causing considerable damage and casualties, but with little obvious gain for the Germans, as neither was a Fighter Command airfield; Portsmouth was also attacked.
The Germans only made two more attacks on radar stations, one of which was a repeat visit to Ventnor, which had already been badly damaged. This was partly because their intelligence, which was universally poor throughout the Battle, indicated that the station was still transmitting. On this basis, they wrongly concluded that the major facilities were located in hardened concrete bunkers. However, for much of August, the Germans chiefly targeted airfields and ports. Again, however, their intelligence was poor: although some thirty RAF stations were attacked over a five-day period, many were not Fighter Command airfields. Therefore, they were irrelevant to the course of the Battle. An attempt by Luftflotte 5 to mount an attack in the north of England from Scandinavia using bombers and Messerschmitt 110 escorts suffered heavy losses and was never repeated.
However, in the fortnight from 24 August to 6 September, the Germans appear to have redirected their attacks more effectively. They switched from merely targeting the airfields nearest the coast to a more considered assault on Fighter Command. It may, perhaps, have been recognised that Goering’s original claim that the RAF would be defeated in four days had been a trifle over-optimistic. In this period, four of the six Sector stations most closely grouped around London were attacked on more than one occasion. Of the other two, Kenley had already been heavily bombed on the 18th and only Northolt, to the west of London, escaped unscathed. Nevertheless, even in this period, seven attacks were directed against Eastchurch, a Coastal Command airfield. No fighter station was so frequently targeted. The real impact of the raids on Fighter Command was felt not through the destruction of hangars or aircraft on the ground, but rather through damage to the crucial Sector operations rooms on the stations and the vital telephone landlines that sustained Fighter Command at every level. Sector operations rooms at Kenley and Biggin Hill were temporarily put out of action by bombing and transferred to emergency facilities in civilian buildings nearby, but these were cramped and did not function to the same level of efficiency.
It was at this time that Dowding and Park, in particular, became seriously concerned by the strain that the Battle was imposing on the air defence system and on Fighter Command's pilots. In early September, Dowding was forced to introduce a form of grading for his squadrons – A, B or C. “A” class squadrons, mostly in 11 Group, were kept fully up to strength so far as possible with combat experienced pilots. “B” squadrons had about fifty per cent experienced pilots and “C” squadrons, which were mostly kept in 10, 12 and particularly 13 Group, had only a few experienced pilots, who would typically be “resting”. The remainder of the squadron strength was made up of raw pilots posted from the training units; it was hoped that they would benefit from receiving on-the-job training by the few veteran colleagues.
What Dowding and his Group commanders did not know was that the Luftwaffe was also under equally severe strain. Altogether, the Luftwaffe lost some 233 fighter aircrew (Messerschmitt 109 and 110 crewmen) killed and an unknown number wounded or missing between 8 August and the end of the month. Around 660 bomber crew were also killed. Fighter Command lost 176 pilots killed in the month. The balance in fighter aircraft saw Fighter Command lose 389 aircraft and the Luftwaffe 694, of which 330 were fighters.
This was, however, a battle of attrition and the outcome of such battles relies on two things. The first is the extent to which each side can absorb and replace its losses, in this case losses of both aircraft and pilots; the second is an accurate intelligence picture of the enemy’s losses and the effect they are having on his capacity to continue the fight, which discloses whether the attritional battle is being won. In both reality and perception, the Luftwaffe’s performance fell critically short. Their intelligence system misled them once again, resulting in a misdirection of resources and effort that was to prove fatal.
At the start of the Battle, the Germans estimated British aircraft production at just 180-300 aircraft per month. However, in part because of the far-sighted pre-war decision to build “shadow” aircraft factories, such as the large Spitfire factory at Castle Bromwich, actual British production was far greater. Indeed, between June and October, Britain produced just over 2,000 Hurricanes and Spitfires, or approximately twice the number lost in the Battle. In addition, an efficient civilian repair organisation had been set up to return damaged aircraft to the front line as rapidly as possible. By contrast, German industry produced only 775 Messerschmitt 109s between June and September and lost 650 during the Battle. As a result, Fighter Command had actually increased its aircraft strength slightly by the end of the Battle, whereas German fighter strength had declined. The same was true of pilots, though many of the replacements, especially though not exclusively on the British side, were very inexperienced. However, German intelligence, misled by the inveterate habit of fighter pilots to claim victories far in excess of reality, credited the Luftwaffe with shooting down nearly 800 aircraft in August. Thus, despite the fact that they calculated British strength reasonably accurately in July, a massive underestimate of production combined with a gross overestimate of the attrition they inflicted, led the Germans to conclude that Fighter Command was close to defeat by the beginning of September.
The erroneous belief that Fighter Command was down to its last hundred operational aircraft led elements within the Luftwaffe high command to conclude that an attack on London would bring up the last tattered remnants of Dowding’s force in its defence. Hitler was also growing impatient. He wished to force a political settlement onto the British, either through the weight of air attack alone or in combination with a threatened or actual invasion. Autumn was drawing closer; soon, the prospect of mounting an invasion across the turbulent English Channel would disappear. He was also infuriated by a Bomber Command attack on Berlin, which was launched after a few stray bombs were mistakenly released over London. The retaliation was urged by Churchill and sanctioned by the Cabinet. Churchill may well have calculated it would rile Hitler, and it did. Having previously forbidden attacks on the British capital, he now lifted the ban; Goering, encouraged by his intelligence staff and those commanders who believed that a climacteric battle would follow, switched the focus of the Luftwaffe’s attacks. On 7 September, the first large-scale raid on London was launched, and others quickly followed.