[rof120]

This is not much but perhaps a start :

Firstly, Nowotny's death is a well-known episode, described many times afterwards.

Secondly, Adolf Galland, "General der Jagdflieger" (General of the Fighters or so) was visiting this airfield, this unit and in particular Nowotny, on this day. Unfortunately there was, it seems, a continuous cloud cover, not very high above ground (perhaps 1,000-3,000 meters, I don't know), so that he only could hear gunfire in the sky and see Nowotny's plane dive vertically out of the clouds until it hit the ground. He described this in his book "Die Ersten und die Letzten" (1953), in English "The First and the Last" (1954 if I remember correctly).