Before 15 August, Luftflotte V's contribution to the Battle of Britain was limited to a handful of attacks by single aircraft or small formations. The difficulty facing the Luftflotte V commander was that while his Norwegian- and Danish-based bombers could reach Britain, they could not do so with a single-seat fighter escort. Yet German intelligence was certain that the only way the RAF could have mounted such a fierce resistance in the south was by stripping the north of its fighter and anti-aircraft defences.
It thus made perfect sense that Luftflotte V should participate in Adler Tag and Adlerangriff. Accordingly, Stumpff launched 18 Heinkel He 115 seaplanes in a feint against Dundee, with 63 He 111 s of 1./ and III./KG 26 flying in on a slightly more southerly course (towards Edinburgh) before turning south towards Newcastle. The Heinkels aimed to attack the RAF airfields at Dishforth and Usworth, with secondary targets in Sunderland and Middlesborough. These aircraft struggled into the air with 6000kg (13,228Ib) bombloads, and were accompanied by 21 Bf 110Ds of I./ZG 76, long-range Zerstörers fitted with the Dackelbäuche - a plywood fairing which covered an auxiliary fuel tank. Unfortunately, the tracks of the He 115 feint and the main raid were too close together, and what should have been a decoy only served to increase Fighter Command's anxiety that a single major raid was inbound.
With a vital convoy sailing from Hull, no chance could be taken, while every fighter squadron in No.13 Group 'itched' to have a crack against the enemy. No.72 Squadron from Acklington was the first to get to the enemy formation, blowing apart two Bf 110s (whose empty but vapour-filled Dackelbäuchen exploded like bombs). No.605 Squadron from Drem were the next on the scene, followed by No.41 Squadron from Catterick and No.79 Squadron from Acklington. Seven Heinkels and seven Bf 110Ds were shot down before the survivors dumped their bombs and fled for home. As they straggled home, one ran into an anti-shipping strike composed of Blenheims from No.235 Squadron at Bircham Newton, and was promptly shot down.
As the Heinkels had flown south along the coast, No.13 Group scrambled the Defiants of No.264 Squadron to protect the convoy which had now left Hull. Even as the Heinkels fled, Chain Home detected another raid, of 50 bombers, flying in towards Driffield. At 1307, No.13 Group scrambled 12 Spitfires from No.616 Squadron and six Hurricanes of No.73 Squadron's 'B' Flight to intercept the raiders. These turned out to be a mix of Ju 88A bombers and Ju 88C Zerstöreren from KG 30, which had set out from Aalborg in Denmark. The Ju 88s raced for the Bomber Command airfield at Driffield, where a Station Defence Exercise was fortuitously already underway, with all guns manned and most personnel already in their slit trenches. The Ju 88s destroyed some 10 Whitley bombers, and badly damaged six more, and many airfield buildings were wrecked or damaged. But the fighters and AA fire downed seven of the attacking aircraft (two bombers and five Ju 88Cs) and three more crashed in Holland on their journey home. The mission proved beyond any doubt that unescorted bomber raids ran the risk of very heavy losses, even over the supposedly undefended north of England.