24 August – 6 September 1940
Phase two of Adlerangriff did not immediately follow the first because of additional concentration of German fighter forces into the Pas de Calais, in an effort to strengthen the fighter protection of the bombing raids.
Fighter escort presented an compelling dilemma for the Germans. On the one hand, the bombers were extremely slow (190 mph) and operated at medium altitudes of 13,000 to 15,000 feet, while the optimum fighting speed for the German fighters was about 300 mph at altitudes above 20,000 feet. So, in close escort the fighters assumed a position of relative disadvantage to intercepting RAF fighters. On the other hand, if the bombers proceeded in daylight without fighter protection, the losses would be unacceptably high.
A compromise was reached between the bomber and fighter commanders: one gruppe (48-64 aircraft) of fighters would provide close escort for each geschwader (144-256 aircraft) of bombers. Another gruppe of fighters would arrive over British defenses ahead of the bombers and with optimal positioning, hopefully, could intercept the enemy fighters before they could reach the bombers.
Thus, after a five-day delay the offensive resumed on 24 August with 1,030 daytime sorties by the Luftwaffe. The main effort was concentrated on airfields, with major attacks on Manston, Hornchurch and North Weald. Fighter Command lost 23 aircraft destroyed and six damaged compared with a loss for the Luftwaffe of 35 destroyed and four damaged. The new tactics were recognized by both sides; fewer bombers and more fighters in the German formations, and a continued reluctance by the British to do battle with the German fighters.
Air Vice-Marshal Keith Park commanding No. 11 Group which carried the brunt of the battle had ordered his pilots to accept combat with German fighters only if Fighter Command’s sector airfields were threatened. Unfortunately, over the next several days, continued focus by the Luftwaffe on Group Sector airfields began to take a toll both in air and ground losses and resulted in reduced operations from these critical fields.
Park’s policy of avoiding unnecessary combat paid dividends on 29 August. In the afternoon, the Germans launched a massive fighter sweep over Kent, conducted by 564 Messerschmitt Bf 109s, accompanied by over 150 Bf 110s. Their obvious intention was pulling the RAF fighters into the air. Initially, the Operations Room assumed that there would be bombers in this group, and sent up several squadrons. When reports came for the spearhead units that the Luftwaffe was fielding a purely fighter formation, the squadrons were called back, avoiding combat. As a result, the RAF losses that day were limited to only 9 aircraft.
On 31 August, Luftflotte 2 launched its heaviest attack of phase two; 1,450 daylight sorties aimed primarily at five aerodromes, Biggin Hill, Debden, Hornchurch, Croydon and Eastchurch. Persistence in the campaign was paying off. Biggin Hill, one of the most heavily bombed RAF bases, was attacked six times in three days. Another worst sufferer at this stage was Manston, which was so heavily attacked with bombs and strafing fighters that it virtually ceased operations.
By early September it was becoming clear that the RAF was losing the attrition battle. During the period between 24 August and 6 September, the RAF lost 273 fighters in combat plus 49 damaged. The Germans lost 308 fighters and bombers with 62 damaged. The German concentration on Fighter Command airfields was, as the Luftwaffe had hoped, forcing the RAF fighters into combat. The resultant war of attrition was one that Fighter Command could not hope to win.
The higher concentration of fighters in the German raids reduced the edge that Fighter Command had previously enjoyed: the Germans could afford to trade Bf 109s, one for one, with Spitfires and Hurricanes!
It is no coincidence that Fighter Command came closest to defeat in this period. Six of the seven sector airfields were extensively damaged, the telecommunication links to and from the operations blocks proving especially vulnerable.
September stood to be the culminating point for Fighter Command. Air Chief Marshal Dowding wrote,
“The rate of loss was so heavy that fresh squadrons became worn out before convalescing squadrons were ready to take their place.”
By the end of the first week in September, Fighter Command was in a desperate situation. Between 8 August and 6 September, 657 fighters had been lost. By using replacement aircraft from repairs and storage, Fighter Command managed, until 1 September, to keep frontline strength at about the same levels as were available at the end of July. However, those reserves had dwindled from 518 Spitfires and Hurricanes (in maintenance and storage) on 6 July, to only 292 by 7 September.
British production figures were no more encouraging. In the last week of August, for example, only 91 Spitfire and Hurricanes were produced while losses reached 137 destroyed and 11 seriously damaged. With losses at these rates, Fighter Command estimated that reserves would be exhausted in three weeks followed by steady depletion of the frontline squadrons. This, of course, would be accelerated if the Luftwaffe could successfully knock out critical production facilities.
The critical problem faced by Fighter Command was the loss of trained fighter pilots. The daily life of a fighter pilot in No. 11 Group was brutally exhausting. During long daylight hours, pilots would fly two to five sorties in one day. P/O John Ellacombe remembered:
“There were fourteen, fifteen hours of daylight each day. You were on duty right through (…) We had seventeen out of twenty-three [pilots] killed or wounded in my squadron in less than three weeks (…) It was a fight for survival”
In July and August, roughly one-fourth of the squadron leaders and one-third of the flight leaders had been killed or removed from flying due to injuries. Experienced pilots numbered no more than 500–less than one-half of Fighter Command’s strength. Stress was also high. One squadron, No. 85, based at Croydon, had fourteen of its eighteen pilots shot down in two weeks, two of them twice.
In phase one of the campaign (8 to 18 August), the RAF lost a total of 154 pilots killed, seriously wounded or missing. Only 63 new fighter pilots were available from the training schools for the same period. During phase two, 24 August to 1 September, the figures were even worse as losses reached 231 pilots, or about 20 percent of the total combat strength of the command! Combat strength in the month of August decreased by almost one-third, from 1,434 to 1,023. The squadron average fell from 26 to 16 operational pilots.
Combat experience was similarly reduced. Many replacement pilots had only a couple dozen hours of total flight time, if that they were needed so badly that there simply was not time for anything more comprehensive. When P/O Roger Hall joined the RAF, he was sent to an Operation Training Unit for flight instruction in a Spitfire:
“We were supposed to have twenty-five hours on the plane. A lot of men completed the course in just two days and were sent right off to squadrons. They were needed so urgently (..) you didn’t really learn to fly until you were in combat. You jolly well had to then! The others in the squadron tried to teach me (…) I was usually more concerned with keeping my aircraft in the air than keeping the enemy out of it. I developed some confidence later on (…) You learned what you had to learn to survive.”
On the ground the persistence of the German attacks was beginning to take effect. The RAF was faced with the real possibility of withdrawing 11 Group to bases north of London. Air superiority over Kent and Essex, at least for a week or two, was in the Luftwaffe’s grasp; the aim of Adlerangrif was near to being realized.
– Derek Dempster, Derek Wood: The Narrow Margin – The Battle of Britain and the Rise of Air Power 1939-1940, Pen & Sword, 2010
– Air Chief Marshal Sir Hugh C. T. Dowding. Despatch submitted to the Secretary of State for Air on August 20th, 1941