Hello, FrankieS!
See
http://www.airwar.ru/history/av2ww/a...uftloss41.html
(in Russian)
Не111Н-4 W/n 3205 (5Z+FA) Wekusta 76 (weather recce unit) MIA 24.6.41, incl. H.Euler.
Forced landing 55 km South of Melitopol in Azow Sea due to motor accident. Next day all crew was captured by fishermen. Their further fate is unknown for me.
He was an able physicist? It is interesting...
Regards,
Andrey