From mid-August, as the Battle of the Channel faded, the Luftwaffe stepped up attacks on RAF infrastructure. These intense raids almost overwhelmed the British air force.
Photo: A policeman and soldier inspect a German Heinkel HE-111 which crashed during an attack on Biggin Hill on 30 August 1940. (Getty Images)
Ed Murrow reports on the Battle of Britain
Ed Murrow, the American broadcast journalist, gives his account of how the air battle moved from the Channel to the Kent coast, and then to London. He describes the living conditions of Londoners and the daily threat that their homes could be destroyed.
Eagle Attack begins
During July, the Luftwaffe had concentrated on attacking Channel convoys and ports. In August, they launched Eagle Attack (Adlerangriff) and began to target RAF airfields and infrastructure in order to control the skies over South-East England.
After some preliminary raids on radar stations on the 12th, Tuesday 13 August was designated 'Eagle Day'. The Luftwaffe set about destroying the RAF in earnest with raids on nine airfields.
On the 15th they flew 2,000 sorties (their highest of the campaign) over England. This time there were significant German losses - 76 aircraft were shot down to the RAF's 35. The 15th became known as 'Black Thursday' within the Luftwaffe.
Churchill had visited Fighter Command's HQ at Bentley Priory that evening, and was gripped by what he had witnessed. He described it as "one of the greatest days in history".
Still the attacks continued. On 18 August Croydon, West Malling and Biggin Hill airfields were bombed and Kenley was particularly badly damaged.
Goering's change of tactics
Between the 19 and 24 August the weather was poor. During this lull Hermann Goering, the head of the Luftwaffe, decided to concentrate efforts solely on Fighter Command's 11 Group, which protected London and the South-East.
The Germans subsequently struck Biggin Hill, Hornchurch, North Weald and West Malling airbases at the end of August and the beginning of September. On 30 August, Biggin Hill, which guarded the approaches to London, was hit twice again and also on the following two days.
One of the successful tactics employed by the Germans was a simultaneous attack by high- and low-level bombers. The low-level Dornier Do 17s could creep in under the, often only partially functioning, radar systems and launch a surprise attack. There were also night raids, making it difficult to carry out vital repairs.
Unsustainable RAF losses
RAF losses were now becoming unsustainable. In the last week of August and first week of September, 112 RAF pilots died and 256 planes were lost. Ground crews also suffered heavy casualties and many maintenance facilities were wiped out. The massive damage to the stations meant, in some cases, small civilian airfields were being used.
However, Goering did not seem to realise the Luftwaffe was so close to overpowering the RAF. Frustrated by the seemingly endless numbers of British fighter planes, he changed his tactics again. This time he switched to the sustained bombing of London, although this was partly due to Hitler's order of retaliation for the attacks on Berlin.
Bombed but not beaten, Fighter Command re-grouped, replaced planes and repaired
airfields and infrastructure.