Towards the end of August, 1940, the Luftwaffe High Command realized that they were not shooting down enough British planes. In order to destroy the fighters, or at least force them away from the southern coast, the Germans needed to focus their attacks on fighter specific targets to compound the damage they were already doing in the air. On 23 August 1940, Herman Goring ordered the Luftwaffe to focus on RAF Fighter Command’s airfields of Air Vice Marshal Keith Park’s 11 Group.
11 Group covered Southern England and already bore the brunt of the Luftwaffe’s attacks. Goring’s new focus was devastatingly effective. Park’s airfields were smashed, and although heroic efforts were made to keep them open, aircraft, and more importantly, pilot availability was affected. On paper, the RAF had more assigned fighter pilots than the Luftwaffe, but the attacks on the airfields prevented the critical “battlefield calculus” from occurring: An experienced and awake pilot + a workable plane + enough fuel + loaded ammunition + a flat runway + an id’d target + time to reach it + a place to do it from all over again a few hours later = victory. The Luftwaffe was making that more difficult everyday. And only Herculean efforts by ground and maintenance crew were keeping British fighter pilots in the air.
Furthermore, as Park’s fighter squadrons were intercepting raids, his airfields were supposed to be protected by 12 Group’s fighters from the north, under AVM Leigh-Mallory. But Leigh-Mallory’s tactics were ineffective, and his squadrons routinely missed the Luftwaffe. Whereas 11 Group attacked raids quickly with a single squadron, 12 Group formed “Big Wings” of three or more squadrons, ostensibly to do more damage i.e. the principle of mass. Theoretically, it should work. But the Big Wings took too much time to form up, thereby becoming the classic “exception that proves the rule“ for the principle of mass, in other words “It’s not mass if it isn’t there”.
Finally, the Luftwaffe attacks unknowingly had a great effect on Air Marshal Dowding’s early warning system. One of the two critical vulnerabilities of the system, the Sector Control Centers, were only located on airfields for administrative convenience. (The other CV was the infamous “Filter Room”.) The Sector Control Centers were responsible for communicating directly with the squadrons, and they were smashed along with the airfields. Many RAF squadrons in late August and early September wasted their time flying around looking for the raids when the SCCs couldn’t direct them to one.
In early September, the pilot situation became critical. Shortfalls were made up by dragooning Fleet Air Arm and Coastal Command pilots, in addition to pilots from Canada, Australia, Rhodesia, South Africa, New Zealand, Belgium, France, Poland, Czechoslovakia, and even a Jewish pilot from Mandate Palestine. But even cutting pilot training hours down to the bare minimum could not produce enough available pilots. At the height of the crisis, British Secretary of State for Air, Sr Archibald Sinclair noted, the RAF had “only 350 pilots to scramble, of which nearly 100 were Poles.”
On 5 September, Dowding had to confront the serious possibility that they needed to pull 11 Group north of London to put their airfields out of the range of the Luftwaffe bombers, or they wouldn’t have enough fighters left to repel any invasion. This would effectively cede the English Channel to the Germans. He planned to brief Churchill on the 8th.