Häfeli DH-1
The Häfeli DH -1, different spelling Haefeli DH -1, was a military aircraft in biplane design of the Swiss designer August Haefeli.
History
The Federal Konstruktionswerkstätte (K W) founded in 1915 a separate department for aircraft flight with a plant in Thun. As a senior engineer assigned to put a Haefeli, who had previously worked at Farman and in Germany at the Aero works by Gustav Otto. There he constructed the reconnaissance AGO CI and C.II which had as a special constructive design feature double tail boom.
After his return to Switzerland, he began work on the DH -1, the conceptual leaning on the dreistieligen, crafted in wood construction AGO C types. The DH -1 also had a fuselage pod with a pusher propeller and double tail boom. The machine had a four wheel chassis, each with a tail skid under the two booms. The crew sat in the fuselage gondola on tandem seats, with the observer, with a machine gun Mg 11 (caliber 7.5 mm) sat in front of the pilot. The input for driving 120 hp from its six-cylinder in-line engine Argus As II of the Argus Motoren Gesellschaft was produced under license by the Brothers Bühler AG in Uzwil.
From the DH- 1, six machines were built with the Federal Konstruktionswerkstätte in Thun, which were used in 1916 to 1919 in the Swiss Air Force as reconnaissance aircraft. However, three aircraft were destroyed in accidents within a year. Since the performance and flight characteristics of the machine is not satisfied, they were decommissioned in 1919 and scrapped. As far as known, there is only a replica, which is located in the plane - Flab Museum Dübendorf.