Hello Sebastian,
Your great uncle was lost on a mission beginning at 17:40 on 5 August 1944. He and his comrades were on a fighter sweep and clashed with twelve Soviet fighters near Mitau (now Jelgava, Latvia). I have more information about this combat and your great uncle, and will contact you offboard in the near future.
If you'd like to contact me, my email address is:
bookie190@hotmail.com
All the best,
Andrew A.
Air War Publications -
www.airwarpublications.com/earticles