February 21 1944

[vinnie]

Hi to all,

I would like to have some more information about the 21st of February 1944, when the allied forces started their Big Week offensive with heavy attacks on Germany. This day many pilots came in action, and among them were Uffz. Helmut Sainisch from 9./JG 1 and Fw. Fritz Haspel and Lt. Erich Mattern, both from 8./JG 1. In the afternoon, all three pilots ditched in the IJsselmeer (according to the losses as registered that day).
Only Haspel survived his crash, but Mattern and Sainisch did not survive the accidents they had. They are now buried in Ysselstein.

Can anybody tell me something more about these pilots and their aircraft? For example if it is certain that all three airplanes crashed in the lake (locations aren't known, correct?), more info about the pilots, maybe some specifications on the Messerschmitts they flew in that day, etc.
It seems to be very likely that Capt. William O'Brien from 357th FG shot one of these Me-109 G-6 machines down above the 'Zuiderzee', the old term for the Ijsselmeer. I wasn't able to connect his victory to one of the 3 specific aircraft so far...

Thank you very much for your help!