11/30/2008. Remarks by Johan Visschedijk: "Produced as the Do K 1, this aircraft was first flown on May 7, 1929, powered by a single nose-mounted 550 hp Siemens-built Bristol Jupiter VI nine-cylinder radial driving a four-bladed propeller. The ten-seat airliner was soon re-engined by four 200 hp Gnome & Rhône 5K Titan five-cylinder radials paired in push-pull configuration, driving four-bladed propellers on the front engines and two-bladed propellers on the rear engines. The aircraft was re-flown in December 1929, designated Do K 2. The aircraft has also flown with two-bladed propellers fitted on the front engines."