Based on the Savoia-Marchetti S56 (whom 31 examples were licence-built in the US), 1st amphibious aircraft built almost entirely from chromium-nickel steel (only the wings were fabric-covered). A 4-seat amphibious powered with a 210hp Kinner C-5, the BB-1 first flew in 1931 or 32.It logged about 1,000 flying hrs on tours of the USA and Italy, once making an emergency landing in the Alps, and later sinking in 4 ft of water, however, both times it was repaired to fly again. In 1934 or 35 its fabric and lower wing were removed, and it was placed on permanent display outside the Franklin Institute