British authorities were every bit as puzzled by these attacks as the Germans were by those of Bomber Command. German air fleets sustained regular attrition throughout the weeks of probing attacks, and achieved little serious destruction or loss of life either on the ground or against Fighter Command. The attacks certainly supplied German airmen with the opportunity to train in night-flying techniques, but they equally gave the British fighter and anti-aircraft defences weeks of precious preparation and practice, and afforded a valuable assessment of German air tactics. This learning-curve was principally of value to the defender. German fighter aircraft had developed tactics in attack that gave them the edge in combat. Flying in loose pairs, with one aircraft protecting the one in front, German fighters could fight more flexibly than the RAF, which kept fighters in tight formations of three. This tactic required a great deal of effort from the two wing aircraft to keep station with the one in the centre, and reduced the defensive assistance each could supply to the others. Such a formation was even more vulnerable if aircraft could not be alerted and sent airborne in time to get level with, or above, the enemy.
The July attacks gave Fighter Command time to iron out the teething troubles in the system of communication and to ensure that squadrons were airborne quickly and deployed economically. Gradually Fighter Command adopted the tactics of more flexible flying, and loss rates were stabilized. The probing attacks also gave the defence practice in responding to a number of different threats simultaneously, and convinced Park at 11 Group that fighters should be deployed in small formations in case attacks were mere feints, or might be followed by successive waves of aircraft. Park’s policy conserved his force, though it often pitted squadrons against much larger formations of the enemy waiting on the chance to engage RAF fighters on unequal terms in large pitch battles.
What the German Air Force learned was less encouraging. German commanders hoped that bombers could be left to make their own way to targets with a loose fighter escort, which would be free to fly off to engage enemy fighters. Fighter Command, on the other hand, was obliged to fight the bombers first, as they represented the primary destructive threat. Gradually German fighters found themselves tied more closely to the bombers. The two forces, bombers and fighters, would rendezvous over the Channel and fly together, fighters slightly to the rear and from 5,000 to 10,000 feet above the bomber formations. By September German fighters were forced to fly in the front and on the flanks of the bombers to give them proper convoy protection. This tactic proved a two-edged sword, for it compelled German fighters to stick with the bombers and reduced the combat flexibility that was the distinctive strength of the German fighter arm.
It was perhaps with a sense of relief that the German Air Force finally received Goering’s order to destroy Fighter Command in four days of intensive attacks in the middle of August. Bad weather interfered not only on Adlertag but on several subsequent days, so that the decisive shift in German strategy was obscured from the British side. Fighter Command did observe an increase in activity against radar installations from 8 August, and on fighter stations near the coast. But only by 18 August did the attack manifestly increase in intensity and move further inland against the entire structure of the fighter force.10 Two days later, with aircraft grounded again by poor weather, Goering issued a directive to the German air fleet commanders to finish off Fighter Command with ‘ceaseless attacks’ by day and by night, in time for a landing in Kent and Sussex now scheduled for 15 September.11
The attack on Fighter Command airfields has always been regarded as the hub of the Battle of Britain. Between 12 August and 6 September there were 53 main attacks on airfields, but only 32 of these were directed at fighter stations. All but two of these attacks were made against 11 Group airfields. There were additional small raids on a wide range of lesser targets; the German Air Force calculated that there had been approximately 1,000 altogether, against industrial installations, air force supplies and communications. There were six main raids against the radar stations on the south coast, most of them on 12 August; they were not attacked repeatedly, and hardly at all towards the end of the second phase of the battle.12 According to those attack reports that gave details of casualties, some 85 personnel were killed, at least seven of them civilians. The single largest loss of life occurred at Biggin Hill on 30 August, when 39 were killed and 25 injured in an accurate low-level bomb attack. The number of aircraft destroyed on the ground was remarkably small, and declined quickly once serious efforts were made to disperse and camouflage aircraft. Air patrols were instituted to protect refuelling squadrons from a sudden surprise attack. In total, 56 aircraft were destroyed on the ground, 42 of them in the first week of the attack, but only seven in the whole of September.13
The airfields that suffered severely were the group most easily reached from France. These included the forward fields at Manston, Lympne and Hawkinge near the Kent and Sussex coasts, all of which were temporarily shut down following a number of attacks. Of these Manston was the most heavily attacked, and was rendered unserviceable on six days and five nights between 14 August and 12 September. Nevertheless, desperate efforts were made to keep airfields operational. After the first attack on Manston on 12 August, 350 men were brought in to carry out repairs and the station was operational again the following day. Aircraft were kept flying after subsequent raids until five raids in one day on 24 August left a number of unexploded bombs. This impeded full recovery for only two days.14
The attack on Lympne on 13 August was particularly heavy, with 400 bombs falling on the landing ground alone. Repairs were slow because construction workers had been sent to Manston to help with the attacks of the previous day. The Air Ministry sent 100 of its own building workers to help, and 150 men were found from firms in the surrounding district. When Lympne was attacked once more, on 17 August, the local men were so upset that they left, with only a small landing strip yet clear. They were induced back only to be hit by a third raid on 30 August. This time five local workers were killed when a bomb hit a slit trench; work was once more delayed. Park took the opportunity of this unfortunate history to press the Air Ministry to supply at least one bulldozer and one excavator at each aerodrome, and to allocate repair parties of 150 men from a central pool of government workers.
German Air Intelligence suggested at the end of August that at least eight airfields had been knocked out entirely and the rest of the system severely depleted. The truth was quite different. Fighter Command adapted itself quickly to the new phase of attack. Park was able to move aircraft to aerodromes further inland and to prepared satellite fields. The inland circle of airfields was then protected by the aircraft of 10 and 12 Groups, while 11 Group fighters fought the raiding aircraft. New tactics were issued to the squadrons on 19 August to cope with the airfield campaign. Fighters were told to engage the enemy over land and not risk combat over the sea, where clusters of enemy fighters waited to escort the bombers back to safety and to destroy any unwary pursuers. Pilots were encouraged to attack bombers first and avoid combat with enemy fighters, while at first notice of incoming aircraft, stations were ordered to send up a squadron to patrol below cloud cover over the airfield to minimize risk of a surprise attack. Once airborne, Spitfires were encouraged to engage enemy fighters, while Hurricanes hunted down German bombers, which may help to explain their different loss rates.15