Transatlantic Superforts Tough Down -- Welcome to Britain fro Superfortress pilot Lt. Col. K. Steele and Col. J. Henry (U.S.A. A.F. Group Commander) from Air Vice-Marshal G. E.N. Guest. The 60 American Superfortress bombers have arrived in Britain after their 5000 mile flight - they are improved versions of the giant planes which dropped atom bombs on Hiroshima and Nagasaki three years ago. July 17, 1948.