Air-Britain Archive 2002-04 / M.Best - Sikorsky american fixed-wing aircraft (1)

The S-33 sesquiplane was produced as two 60 hp examples, a single-seater seen here at the 1925 National Air Races, and a two-seater. The 60 hp L-4 three-cyl radial engine was produced by Charles L Lawrance who also designed the nine-cyl radial that became the Wright Whirlwind.