A Boeing 314 Clipper flying over San Francisco (1940). The Clipper was a long-range flying boat produced between 1938 and 1941. It used the massive wing of an earlier Boeing bomber to achieve the range necessary for flights across the Atlantic and Pacific Oceans. Twelve Clippers were built; nine were brought into service for Pan Am, the remaining three were sold to BOAC however, later they were all transferred to military usage. None of the dozen 314s built between 1939 and 1941 survived beyond 1951; all 12 having been scrapped or cannibalized for parts, or otherwise written off.