Before the advent of the long-range escort fighter, American bomber groups flying daylight bombing raids into the heart of Nazi Germany were at the mercy of the Me109s and Fw190s of the Luftwaffe. Losses on a single mission could sometimes exceed 30%. As the B-17s and B-24s were brutally torn out of the skies by 20 and 30mm cannon fire, the whole feasiblity of daylight bombing was called into question. Then the P-51 Mustang arrived. The P-51 was the only fighter with the range to escort bombers deep inside Germany - and it was a natural killer. By early 1944, the Luftwaffe had to be smashed as a prelude to D-Day and the P-51 would do the smashing, while the 100-mile-long bomber formations acted as fighter-bait. Packed with archive footage, dramatic gun camera film and exclusive interviews with Mustang pilots, this programme is a tribute to the fighter aircraft that won air superiority for the Allies in the war-torn skies over Europe.