Bomber Command didn't do much to help Fighter Command during the BoB or Blitz. If the BoB/Blitz was more successful for the Germans then BC could be re-tasked to attack German airfields and other Luftwaffe targets.
From Stephen Bungay’s ‘The Most Dangerous Enemy, A History of the Battle of Britain’ (A very good book by the way).
‘Bomber Command’s efforts against the invasion forces peaked during September, when some 60% of its strength was directed against the Channel ports. For several nights the whole of the available force attacked the barges. Between the end of July and the beginning October, 36% of Bomber Command’s sorties were made against invasion shipping and destroyed about 13% of the assembling craft. A further 17% were against airfields and 14% against the German aircraft industry.’
He goes on to say that because of the numbers involved, it would have been very difficult to achieve anything against the airfields.
From Tami Davis Biddle’s ‘Rhetoric and Reality in Air Warfare: The Evolution of British and American Ideas About Strategic Bombing, 1914 – 1945
Page 187
‘in return for 1,097 sorties against airfields (and the loss if sixty-one aircraft), Bomber Command destroyed five German aircraft on the ground and damaged twelve. Damage to airfields was hard to assess, but, as the official historian of the Battle of Britain explained dryly, it “seems to have caused the enemy no serious embarrassment”.
Interestingly, this should have been foreseen
From ‘Dowding of Fighter Command’ by Vincent Orange
Page 116
By now, Dowding had foreseen that attacks would be made on his aerodromes and wondered what would happen to fighters dispersed around them. In his usual way, he urged a test and after long argument was allowed to have 30 obsolete Bristol Bulldog fighters spread in a circle on Salisbury Plain. They were attacked for a week in July 1938 by various bombers from high and low level, with large and small bombs, incendiaries and machine gun fire. At the end of the week, Dowding composed a report more devastating than the bombing: 22 tons of high explosive bombs, 1,000 incendiaries and 7,000 rounds of machine gun fire had destroyed three bulldogs, damaged one beyond repair, left 15 with minor damage and 11 completely unharmed. These shockingly bad results indicated that dispersal alone might give fighters a fair chance of survival, unless the Luftwaffe proved to be more accurate than Bomber Command. The test also demonstrated the appalling gulf between theory and practice in RAF doctrine with regard to bombing.