He was an observer, born on 18th March 1909. He was murdered as a POW. Returning from a raid on Manheim, On 8th November 1941, the aircraft was out of fuel and the pilot attempted to land his plane on an airfield in Belgium. He landed at St Trond near Liege, which was a Luftwaffe fighter base. The crew all survived and were made Prisoners of War, but not before destroying all papers that might be useful to the Germans and setting the aircraft on fire.
Various sources mention that F/O Jerzy Tomasz Mondschein, aged 35, was one of 50 Officers executed on 29th March 1944 after an escape from Stalag Luft III (The Great Escape). Prisoner of War No P0913 F/O Jerzy Tomasz Mondschein, born 18 March 1909, recaptured in the Reichenburg area and murdered at Brux 29 March 1944 by an unknown Gestapo killer; he was cremated at Brux. His ashes were later buried in the Old Garrison Cemetery at Poznan, Poland. It is a sad irony that he was incarcerated in Stalag Luft III in Sagan (now Zagan) which is in Upper Silesia, Poland. Unconfirmed reports suggest that he was a concrete expert and built all the trapdoors for the tunnels.
The killers are unknown but the executions of Mondschein and three others (F/Lt Lester J Bull DFC of 109 squadron RAF, F/Lt Reginald V Kierath and Squadron Leader John EA Williams DFC, both of 450 squadron RAAF) were orchestrated by local Reichenburg Gestapo leader Bernhard Baatz, Robert Weissman and Robert Weyland. Baatz and Weyland lived on with impunity and with the complicity of the Russian authorities. Weissman was later arrested by the French military authorities but his fate remains unknown.
Before their execution, the four escapees were interrogated in custody at Jelenia Gora prison.
See also https//304squadron.blogspot.com/2020/11/jan-wincenty-mondschein.html