04/30/2012. Remarks by Johan Visschedijk: "This aircraft was built under license by the A.G. für Dornier-Flugzeuge (Swiss Dornier works, also known as Doflug) at Altenrhein, and delivered to the Swiss Fliegertruppe (air force) with the s/n U-89 on July 19, 1940. It was used as an aerobatic trainer and equipped with a gun-camera it was also used for air combat training. On June 13, 1968 it was struck off charge, and a year later, June 4, 1969 it came on the civil registry as HB-MKM.

During the winter of 1969-1970 the aircraft was re-engined with a 200 hp Lycoming IO-360B1B engine, the engine cover was replaced by a streamlined one. This conversion was done by the young aerobatic pilot Michael Brandt as his thesis for his engineering study, hence the aircraft is also referred to as the Brandt Bü 133BM. Named Antarès, Brandt flew the aircraft again at La Chaux de Fonds on May 5, 1970. In 1985 it was sold to Appair based in Appenzell.

Appair was formed in 1983 by Hanspeter Köstli and Albert Zeller, with the purpose to preserve and use historic aircraft. Usually flown by Köstli, the aircraft was refitted with an original Jungmaster cowling. The aircraft was destroyed in a crash and ensuing fire at Sonnenberg near Abtwil on January 5, 1999; the pilot was seriously injured. Three years later, however, a complete rebuild started, using parts of the burned metal tube skeleton, and the aircraft made its second maiden flight in the fall of 2008."