From Wikipedia: The H√§feli DH-1 was a 1910s Swiss two-seat reconnaissance aircraft, built by the aircraft department of the Federal Construction Works (Eidgenoessische Konstruktionswerkstaette, K+W) at Thun, Switzerland.In 1915 K + W set up their aircraft department and employed August H√§feli as chief engineer. H√§feli had previously designed the AGO C.I and AGO C.II, German reconnaissance biplanes. His first design was the H√§feli DH-1, similar in concept to his designs for AGO Flugzeugwerke. The DH-1 was a three-bay biplane of wood and fabric construction, it had a fuselage pod with tandem seating for the two-man crew and twin booms mounting the tail. The DH-1 was powered by an Argus As II engine built under licence by Buhler Brothers Limited. Six aircraft were built.