The Buhl AirSedan was a family of American civil cabin sesquiplane aircraft developed and manufactured by the Buhl Aircraft Company in the late 1920s. One example completed the first transcontinental non-stop roundtrip flight, made in 1929 by the CA-6 Spokane Sun-God, and the first Pope to have flown did so in a Buhl Airsedan. The Airsedan series were designed by Etienne Dormoy following the departure of Alfred V. Verville from Buhl, with whom he had worked previously. Dormoy had worked with Deperdussin before World War I, flew combat operations during the war before returning to work with SPAD, travelled to the US to coordinate production of SPADs with Curtiss until the project was cancelled with the end of the war. He then worked with Packard on automobiles for a year in 1919 before working as a civilian with the United States Army Air Corps with Verville, who convinced him to work at Buhl. As a Frenchman, he was familiar with the advantages of the sesquiplane concept as it was a popular configuration in France, such as with the Breguet 26T airliner, but rare in the US. The fuselage framework, lower wing and empennage were welded chromium-molybdenum alloy steel tubes faired with wooden battens, with the lower wing integral with the fuselage structure. The upper wings were built around spruce spars, with built up ribs made from spruce and plywood. The entire airframe was covered with doped aircraft-grade fabric. To reduce control forces, projecting aerodynamic balance horns on rudder and elevators, while inset aerodynamic horns were used on the ailerons, which were fitted to the upper wing only. To provide trim control, the rudder was ground adjustable while the elevators could be adjustable in flight. Depending on the models, three different designs of lower wings were used - either constant chord with reversed N struts on the CA-5, a triangular wing with a vee strut on the CA-3, CA-6 and CA-8, or a constant chord wing with two rigged struts, on Canadian built CA-6Ms. All were conventional sesquiplanes with fully enclosed cockpits, fitted with dual controls in front of a passenger cabin. The number in the designation generally referred to the number of occupants as originally designed, with a larger number of seats corresponding to a larger airframe. The first variant built was the CA-5, while later variants had a much slimmer fuselage, a greatly improved windscreen design and a modified cockpit. The CA-5 had the undercarriage legs connected to the fuselage, and part way out from the fuselage, on the lower wing. The CA-3 had the undercarriage mounted solely to the fuselage, while the CA-6 and CA-8 had additional bracing struts from the top of the fuselage to the lower wing which allowed the undercarriage track to be widened. Buhl asserted that its undercarriage design reduced camber changes during landing, and the tendency to yaw due to bumpy ground. The CA-6 was certified to use Edo J-5300 floats. Canadian production. After Buhl had ceased operations in 1932 due to declining sales as the Great Depression deepened, the drawings and jigs were purchased by the Ontario Provincial Air Service (OPAS) in Canada who then built four CA-6M's for use as fire spotting aircraft at their facility in Sault Ste. Marie between 1935 and 1937. These differed from the original aircraft in having Canadian Vickers floats, a new fin and rudder and larger lower wings. Due to the excessive weight of the Canadian-Vickers built floats, the first Ontario Provincial Air Service-built CA-6M refused to leave the water until given a more powerful 440 hp (330 kW) Pratt & Whitney Wasp engine. For details of opertational history and 20 variants, click here.
