In the predawn hours of June 13, 1944, a jet-propelled German missile, designated the V–1, left a launching pad in the Pas de Calais area of France and sputtered across the English Channel, landing near the center of London. Within twenty-four hours, the Germans launched almost 300 of these flying buzz bombs against the United Kingdom. The Allies reacted, under the operational name of Crossbow, by attacking the launching sites with fighter-bombers. Later, in addition to using fighter patrols, radar-controlled antiaircraft guns, and barrage balloons, the British requested the use of heavy bombers to destroy the launch sites. Spaatz objected to the diversion of his heavy bombers away from the strategic mission, but in response to British losses Eisenhower ordered Spaatz to attack the launch sites. In September 1944, the problem worsened because the Germans began launching the V–2, a rocket-powered ballistic missile that flew at almost 4,000 miles per hour and descended without a warning noise. The Allies responded by bombing not only the launching sites but also the support installations. Regrettably, these bombing attacks were largely ineffective and the German “vengeance” weapons were not neutralized until the Allied ground armies overran the launch sites. The raids cost the lives of more than 700 Allied airmen and destroyed at least 154 aircraft.