The Boeing Model 81 was an American training aircraft built by Boeing in 1928. The Model 81 was a development of the Model 64. It was powered by a newly developed engine the 125 hp Fairchild-Caminez 4-cylinder radial engine. Operating at a much lower rpm than most engines (1000 rpm) it required the use of a large high-pitch propeller.
Made by Boeing.
It is the successor of the Boeing Model 64 .