03/31/2012. Remarks by Johan Visschedijk: "EKW was the commonly used abbreviation for Eidgenössische Konstruktionswerkstätte (Federal Constructions Workshop, also known as K+W) at Thun, Switserland. Produced during WW II, the pictured aircraft was delivered to the Swiss AF on October 13, 1943. It was one of the 23 C-3603s that were converted by EFW (Eidgenössisches Flugzeugwerk, Federal Aircraft Factory) to a C-3605 in the period 1968-1972, it was finally withdrawn from service on July 15, 1987."