August Häfeli had worked for Farman and Aerowerke Gustav Otto before being appointed chief engineer of new aircraft department of K+W, Eidgenössisches Konstruktions Werkstatte (Ateliers Fédéraux de Constructions) at Thun in 1915. Six DH-1 2-seat pusher reconnaissance aircraft were followed by 6 tractor DH-2, 54 DH-3, 79 DH-3a, 59 DH-5 and 20 DH-5A, all 2-seaters used for training, recon and as mail carriers. Factory run down 1927.