Bertin compound


In France in 1908, Bertin, a motorcyclist, and Boulline, a mechanic from Puteaux, built a machine with variable incidence angle biplane wings, a 2.2m tractor propeller and a 2m lifting propeller. Bertin built a 150hp flat eight-cylinder motor (weighing 120kg) to power the 433kg vehicle. It could hop off the ground for a few feet, but lacked adequate control to achieve any stability.