On this day, on 12 May one of the fiercest and lengthiest air battles over the Reich itself was fought. This day when the 8th USAAF initiated a new chapter in the Allied bombing offensive against the Reich. This day a series of attacks on the German fuel industry was launched. As the Allied planners were convinced that a serious fuel shortage resulting from attacks on refineries and hydrogenation plants must hampered the Luftwaffe ability to conduct operations, furthermore it was believed that such attacks would ultimately rob the German armed forces of their mobility.

The 8th US Air Force dispatch no less than 889 4-engine bombers to attack four of the most important hydrogenation plants in Germany: Leuna, Merseburg, Böhler and Seitz. To protect the US bomber force an additional 950 escort fighters was dispatched. The Luftwaffe put up a considerable force of 16 day fighter and two heavy fighter Gruppen with a total of 515 fighters.

The II./JG 53 scrambled at 11.30 from Eichborn and later joined II./JG 27 and elements of JG 1. On their way to their target while still climbing the gruppen was bounced by US fighters and were forced to accept battle. After the II./JG 53 manage to disengage they spotted the Weirmots over Frankfurt and made contact over the Taunus Mountains at 12:20. One abschuss was claimed by II./JG 53, a B-17 downed by Obfw Russ for his 22 victory.

When the days fighting was over the Luftwaffe reported a total of 91 abschüsse for an own loss of 64 fighters with another 16 damaged. The USAAF force on the another hand claimed 61 enemy fighters for an own loss of 7 fighters and 55 bombers. The II./JG 53 lost in all six fighters, including the Bf 109 G-6 flown by the Gruppenkommandeur Hptm. Julius Meimberg, with one pilot killed and another two wounded for a total of six filed victories, four B-17 and two P-51 Mustangs.

Oblt. Günther Seeger the Staffelkapitän of 4./JG 53 flying in this machine was force to belly land this machine "White 1" this day due to battle damage.

As a result of the 8th USAAF attack this day on the German hydrogenation plants, the production fell by 14% and approximate 25,000 tons of fuel went up in smoke.