Eidgenössiche Konstruktions Werkstätte formed Thun 1914, built aircraft designed by Haefeli: DH-1 pusher (6), DH-3 2-seat tractor (110), DH-5 (60 in 1919) and DH-5A (22 in 1928). In 1932 produced Fokker C.V jointly with Dornier, and replaced this with C-35 flown 1935, 80 built 1937-9.