To add to the limited number of Junkers Ju 52 planes the Germans used other planes like the Heinkel He 177 . General Richthofen told Manstein on 27 November that the Luftwaffe could not supply 300 tons a day by air. Manstein now saw the problems of a supply by air. The next day he made a report which said that the supply by air would be impossible. He said the Sixth Army should try to escape. He said that giving up Stalingrad would be a difficult loss, but that it would keep the Sixth Army intact. Hitler said that the Sixth Army would have to stay at Stalingrad and that the air force would supply it until the Germans could attack the Soviets.