Between 1942 and 1945 the US built up from scratch the largest overseas air force in its history based on over 120 airfields in Britain. The 8th US Army Air Force, The 'Mighty 8th' as it became known. Its declared objective was to dismantle the German military and industrial machine and to do so by daylight bombing. Over 55,000 young Americans lost their lives in the process. This is their story. William Wyler's classic colour film Memphis Belle remains the most memorable true story of WWII. Now producer William Woollard reveals the whole story including previously unseen and remarkable archive footage of an air force that eventually grew to more than 3500 bombers and fighters.