Late in World War II, the Luftwaffe used ramming to try to regain control of the air. The plan was to dissuade Allied bomber pilots from conducting bombing raids long enough for the Germans to create a significant number of Messerschmitt Me 262 jet fighters to turn the tide of the air war. Only a single dedicated unit, Sonderkommando Elbe was ever formed to the point of being operational, and flew their only mission - only a month before the end of the war in Europe - on April 7, 1945. Although some pilots succeeded in destroying bombers, including one ramming during the sole mission that Sonderkommando Elbe undertook that took out two B-24s at once with one Bf 109G, Allied numbers were not significantly reduced.
Me-109 model from www.colacola.se
B-17 model from "Wings of Power" for FSX.
BG sky from mayyang.com