 Complete the following phrase:  By 11 September, the fuel situation was acute, and logistics failed. On the first day his units were flying three missions every day, now it was reduced to one per day. Despite the problems, by 8 September Richthofen was preparing an assault on Warsaw. The raids had barely begun when a major threat developed behind him. A Polish counter offensive engaged the German Eighth Army, in an attempt to reach the Vistula river. Richthofen joined the assault and counterattack from the air. For three days the Germans bombed Polish forces contributing to the success in the Battle of Radom and 