Dornier Merkur

The Dornier Merkur, internal designation Do B Bal, was a single-engined German passenger aeroplane built by the Dornier works at Friedrichshafen. It was a development of the Komet III, whose chief weakness was low engine power caused by the restrictions of the Treaty of Versailles, and used the same airframe with the much stronger 600 horsepower BMW VI engine in place of the Rolls-Royce Eagle, a belly radiator instead of the nose radiator and a strengthened structure. The high-wing monoplane seated six passengers in a closed cabin and two crew in an open cockpit, on a fixed undercarriage with a skid. It first flew on 10 February 1925. In June 1926 Walter Mittelholzer and Georg Zinsmaier set seven world records in one, and Mittelholzer later flew a float-equipped Merkur from Zurich to Cape Town in 78 days. Lufthansa was the main customer with 30 of the 50 built, a geared BMW VI U version was called Merkur II, and a replica stands in the Dornier Museum at Friedrichshafen.