Häfeli DH-3
The Häfeli DH -3 was a biplane reconnaissance aircraft manufacturer Federal Konstruktionswerkstätte (K W).
History
Beginning of 1917 was K W the contract to build 30 copies of DH -3, which was an improved version of the previous draft DH -2, except that the cell remained essentially unchanged. However, the suspension was found to be susceptible, and there were problems with the cooling of the engine, to provide an improved system has been installed.
24 specimens were prepared by the Argus As II engine, which in 1923 pulled out of the use, when it was found deficiencies in the structural strength of a first 600 hours flown cell. A DH -3 led on January 8, 1919 the first airmail flight in Switzerland, which took place between Zurich / Dübendorf and Bern.