at Naval Air Station Hampton Roads, Norfolk, Virginia. Fat Man nuclear bomb The first US nuclear bombs, the Fat Man (Mark III) had incredibly bad ballistics. Los Alamos engineers, in an effort to fit the awkward shape of the weapon into an aerodynamically sound shape, based the Mark IV bomb casing upon the shape of the C-type blimp envelope. Operators United States Navy United States Army Specifications (typical) See also List of airships of the United States Navy References 1910s United States patrol aircraft Airships of the United States Navy Goodyear aircraft Aircraft first flown in 1918