According to the loss list available at
http://www.rafandluftwaffe.inf, on 15 April 1944 seven He 111 of I./KG 26 were destroyed and three damaged on the ground by P-47s of 56th FG.
From what I know, 56th FG claimed 8 He 111 destroyed and several damaged during this attack (and lost two P-47s to Flak).
Luftwaffe loss lists in 1944 have been lost, and it is unusual to known ground losses for this year, so I wonder if the first source used 56th FG claims, or if a surviving source is listing the I./KG 26 losses for this day ? Maybe ULTRA ?
Thanks in advance
Laurent