This Fieseler-built Fw 190 A-7 with 19 abschuss balken on the rudder had been accredited Rüdiger von Kirchmayr, the kills matching his claims fled on 29 April 1944. However this "White 2" with the W.Nr. 643949 was in fact a 4th Staffeln machine that was flown by Lt. Otto Bach

Its known that Bach´s total on 29 May 1944 was sixteens confirmed victories, the day when he had been awarded the DK in Gold. However it is not known how and when between 29 May and the date of his death he filed his additional nine additional victories. Most likely the 19 killbars on the rudder included three unconfirmed victories filed by him.

During his time with JG 1, he served on 12, 4, and 5 Staffel. Around May 1943, he transferred to 5./JG 1. Bach was fortunate to escape injury on 29 May 1944 when his Fw 190 overturned on landing when he ran into a bomb crater. He was appointed Staffelkapitän of 7./JG 1 on 15 July, 1944. Otto Bach that had a long and distinguished career as a fighter pilot. Bach was one of the more seasoned fighter pilots who flew with JG 1 and served as a steady and reassuring influence over the many green pilots entering his Staffel.

Fritz Wegner, another JG1 pilot, remembers the day he was assigned to 5./J.G.1 as a fresh recruit. "I was nominated as wingman to Oberfeldwebel Otto Bach. He came straight to the point: being a green pilot, I only had one thing to do - remain glued to him. 'You get on my wing and stay there.' It wasn't always very easy, but both our lives depended on it. So we would go through the masses of Viermots [four engined bombers]. I, thinking we would fall to the bursts of steel, he showing me not only the way to attack, but also the way to survive." Thanks in part to Bach's willingness to mentor his young comrade, Wegner would survive the war, finally reaching the rank of Leutenant-General in the 1970s.

Leutnant Otto Bach would fly his last combat mission on 26 November 1944. The day when II./JG 1 was one of the Gruppen intercepted 1 137 USAAF bombers attacking targets in the Ruhr area. The bombers were escorted by almost 700 fighters. Overwhelmed by superior numbers, Bach, by than the Staffelkapitan of 7./JG 1, was killed when clipping trees and crashing to his death in his Fw 190 A-9 "yellow 15" during a low-level tree-top chase by Mustangs in the vicinity of Rochau near Stendal.