Tiltjet

A tiltjet is an aircraft propulsion configuration that was historically tested for proposed Vertical Take-off and Landing (VTOL)-capable fighters. The tiltjet arrangement is, in concept, broadly similar to that of the tiltrotor; whereas a tiltrotor utilises pivotable rotors, the tiltjet employs jet engines capable of moving to angle their thrust between downwards and rearwards positions. A typical arrangement has the engines mounted on the wingtips, in which the entire propulsion system is rotated from axial to dorsal in order to achieve the transition from hover or vertical flight to horizontal. Aircraft of such a configuration are fully capable of performing VTOL operations, akin to a helicopter, as well as conducting high speed flights. However, the configuration has been restrained to experimental aircraft only, as other configurations for VTOL aircraft have been pursued instead. During the 1950s, rapid advances in the field of jet propulsion, particularly in terms of increased thrust and compact engine units, had contributed to an increased belief in the technical viability of vertical takeoff/landing (VTOL) aircraft, particularly within Western Europe and the United States. During 1950s and 1960s, multiple programmes in Britain, France, and the United States were initiated; likewise, aviation companies inside West Germany were keen not to be left out of this emerging technology. Shortly after 1957, the year in which the post-Second World War ban upon West Germany operating and developing combat aircraft was lifted, German aviation firms Dornier Flugzeugwerke, Heinkel, and Messerschmitt, having also been allowed to resume their own activities that same year, received an official request from the German Federal Government that urged them to perform investigative work on the topic of VTOL aircraft and to produce concept designs. Around the same period, the American aviation company Bell Aircraft were investigating their own designs for VTOL performance.