Until the last week of July, Osterkamp's JG 51 was the only single-seat fighter unit in action across the Channel. And the strength of this unit had fallen until, on 12 July, the third Gruppe of JG 3 was assigned to them, to keep their serviceability up to the region of sixty or seventy aircraft.

Using their small force, the two colonels Fink and Osterkamp showed considerable skill as they probed the British defences, discovered the response times, and found and hit coastal convoys, which were numerous along the south-east coast. Usually the fighters remained close to the bombers, but now and again 'Onkel Theo' released them for fighter sweeps across Kent. These 'Freijagd' (free-hunt) flights were of limited duration because of the Bf 109's short range.

Dowding's response was cagey. Park (Group commander for south-east England) sent only small formations against the raids and let the Freijagd fly unhindered. In the radar stations, the girl operatives began to realize that they succeeded only by working quickly — by making 'educated guesses' about enemy intentions while the bomber formations were still at the extreme edge of radar range.

Al Deere, from Wanganui, New Zealand, had travelled half-way across the world in order to join the RAF in 1937. By July 1940 he was flight commander with 54 Squadron, and after a month of intensive air fighting he had got his DFC from the hands of the King, at a ceremony held at Hornchurch airfield. By now he was as experienced as any fighter pilot that the British had.

On 9 July[8] he was leading a formation on his fourth flight of the day when they found a German rescue float plane painted white with eight large red crosses, flying at wave height. It was escorted by a dozen Bf 109s, flying close behind it.

While one section attacked the float-plane, Deere dived upon the Messerschmitts, which split into two formations, climbing steeply to right and left respectively, turning as they went. Deere remembered this tactic and later used it with some success. Now Deere's flyers broke and individual combats started. Deere noted with satisfaction the way the new De Wilde bullets made “small dancing yellow flames” as they exploded against the enemy fighter. He found this a valuable way of judging the effect of his gunfire.

“I soon found another target. About 3,000 yards directly ahead of me, and at the same level, a Hun was just completing a turn preparatory to re-entering the fray. He saw me almost immediately and rolled out of his turn towards me so that a head-on attack became inevitable. Using both hands on the control column to steady the aircraft and thus keep my aim steady, I peered through the reflector sight at the rapidly closing enemy aircraft. We opened fire together, and immediately a hail of lead thudded into my Spitfire. One moment the Messerschmitt was a clearly defined shape, its wingspan nicely enclosed within the circle of my reflector sight, and the next it was on top of me, a terrifying blur which blotted out the sky ahead. Then we hit.”

The crash snatched the control column out of Deere's hands and the cockpit harness bit painfully deep into his shoulders. The engine was vibrating, and the control column was jumping backwards and forwards. As Deere watched, the engine gave forth smoke and flames, and before he could switch off the ignition the propeller stopped. Now Deere could see that its blades were bent double: the Bf 109 had scraped along the top of his Spitfire.

Unable to get his hood open, Deere coaxed the aircraft into a glide towards the distant coastline, while he struggled to get out. With skill to match his amazing good fortune he brought the wrecked aircraft down into a field, very near to Manston airfield. Still unable to open his hood, he smashed his way out of it, his "bare hands wielding the strength of desperation," he said. He got clear of the wreckage, which burned brightly as the bullets exploded. "Won't you come in and have a cup of tea?" said a woman coming out of a nearby farmhouse.

"Thank you I will," said Deere, "but I would prefer something stronger if you've got it."

Modestly Deere got back to his squadron expecting nothing more than a couple of days off. But they were so short of pilots that his commander asked him to fly again immediately. The squadron had lost two pilots to the Messerschmitts and when Deere got to dispersal there were only four Spitfires serviceable. "You needn't expect to fly this morning," he was told.

"I'm in no hurry," said Deere.

The Luftwaffe needed regular weather reports and more photo coverage of its targets. Not realizing what a sitting duck lone aircraft were for radar, the Germans came one at a time, flying out over the North Sea to what they hoped was an undefended landfall. Often it proved fatal for the German crew, but sometimes there were surprises. On 10 July, a Do 17 looking for a convoy off the North Foreland had no less than an entire Gruppe of JG 51 flying escort on it. The other actions of the day were no more than skirmishes but by the end of it Fighter Command had flown over 600 sorties.[9]

On this day there was an endless stream of lone German aircraft. The RAF responded by sending lone aircraft to meet them. Often the squadron commanders reserved that job for themselves. Not long after dawn, for instance, Peter Townsend — the commander of 85 Squadron at Martlesham — was at the controls of his Hurricane VY-K, climbing out of ground mist into low grey cloud and heavy rain. The Controller's voice took him up to 8,000 feet where, in cloud, he made a perfect interception.

This Dornier Do 17M was Y5/GM from Kanalkampf-führer Fink's own Geschwader, II/KG 2, the ‘Holzham-mer’. It came to England in a wide sweep out over the North Sea, reaching the coast near Lowestoft. Forbidden to bomb the mainland in daytime, after what one of the crew described as a little “sight-seeing” they dropped their ten tiny (50-kg) bombs over some shipping in the harbour.

The crew had mixed feelings about the cloud and rain; it made the pilot's job more difficult, and reduced visibility for the bomb-aimer and gunner, but it was reassuring to think that any RAF fighters would be having the same sort of problems in locating them. The Germans were content, and as the nose of the Dornier turned for home the crew began singing “Goodbye, Johnny”… The melody was interrupted by the sudden shout of a gunner, Werner Borner, “Achtung, Jдger!”

The Jдger was Peter Townsend, who could hardly see through his rainswept windscreen, and so slid open the cockpit cover to put his head out into the rainstorm. He had not had to rely on visibility until the last few moments, for the single Dornier had provided the radar plotters with a blip on the cathode-ray tube no more difficult to interpret than the ones set up as pre-war exercises.

And Townsend was a peacetime pilot, a flyer of great skill and experience. His eight Browning machine guns raked the bomber. Inside the bomber there were “bits and pieces everywhere: blood-covered faces, the smell of cordite, all the windows shot up”. Of the crew, the starboard rear gunner was hit in the head and fell to the floor. A second later another member of the crew — hit in head and throat — fell on top of him. There was blood everywhere. But “our good old Gustav Marie was still flying,” remembered one of the crew. Townsend had put 220 bullets into the Dornier but it got home to Arras, and all the crew lived to count the bullet holes.