Dornier Do 29
The Dornier Do 29 was an experimental aircraft developed by Dornier Flugzeugwerke and, the Deutsche Versuchsanstalt für Luftfahrt (German Aviation Laboratory) in the 1950s, used to test a tilting-propeller system for Vertical/Short Take-Off and Landing (V/STOL) aircraft. The concept was proved successful in flight testing; however, no further development of the system or aircraft was proceeded with, and at the conclusion of its test program the Do 29 was retired.