Hello Evgeny
The only source that I was able to find concerning USAAF claims against Me 262 jet fighters lists the first American claim as having occurred on 28 August 1944. The cause for the loss of Thierfelder appears to be rather uncertain with the III./ZG 26 unit diary stating that it was due to aerial combat with 15 enemy fighters while several members of EKdo 262 state it to have been due to a technical malfunction, including Leutnant Viktor Preusker who I have read claimed that he could remember that the cause of the crash was the detachment of the stator rings on both engines. On the other hand Dan O'Connell states that the loss could have been due to damage caused by return fire from the bombers that Thierfelder was to have engaged... Much speculation but little in the way of hard evidence. I sort of lean to the possibility of a technical malfunction in light that there is no evidence from American sources of a Me 262 having been shot down that day. What do you think?
http://www.afhra.af.mil/shared/media...100315-020.pdf
Horrido!
Leo