In 1943, the large and slow Flying Fortresses, used in the US Air Force's daylight bombing raids, were being shot out of the sky at a rate of up to 60 per day. Only one fighter plane could save them - the single-seat P51 Mustang. The P51 enabled American pilots to fly eight-hour missions - by the end of the war, it accounted for half of all German planes destroyed, either in the air or on the ground. American and German veterans recount the legend that was the Mustang.