Editing Rolls-Royce Dart (section)

==History==
Designed in 1946 by a team led by Lionel Haworth, the Dart engine was derived using experience gained from the earlier more powerful [[Rolls-Royce Clyde]] turboprop. A two-stage centrifugal compressor was specified to achieve the desired overall pressure ratio. A 3 stage, shared load, axial turbine was used to drive both the load (via a reduction gearbox) and the compression system. A photo showing a cutaway section of typical Dart engine is given below. 

Unlike the Clyde, the engine lacked a free power turbine. Consequently, under normal operating conditions, the power delivered to the propeller could not be modulated at a fixed prop speed.<ref name="The F27 Rolls Royce Dart powerplant">{{Cite web| title=Fokker F27 Mk 500 Friendship, G-JEAH, 4 August 1995 | url=https://assets.publishing.service.gov.uk/media/5422ef5f40f0b6134200023b/dft_avsafety_pdf_500083.pdf | archive-url=https://web.archive.org/web/20170204065700/https://assets.publishing.service.gov.uk/media/5422ef5f40f0b6134200023b/dft_avsafety_pdf_500083.pdf | archive-date=2017-02-04}}</ref>

The Dart was initially rated at 890 shp and first flew in October 1947 mounted to the nose of a converted [[Avro Lancaster]]. 

Improvements in the design boosted power output to 1,400 shp in the RDa.3, which went into production for the Viscount in 1952. The RDa.6 increased power to 1,600 shp and the RDa.7 to 1,800 shp by incorporating various improvements including a larger diameter second impeller.

Later Darts were rated up to 3,245 shp and remained in production until 1987, with approximately 7,100 produced, flying some 170 million hours.<ref name="Sutton Publishing 2006, p.195">"World Encyclopedia of Aero Engines – 5th edition" by [[Bill Gunston]], Sutton Publishing, 2006, p.195</ref>

The Dart was also produced under licence in India by [[Hindustan Aeronautics|Hindustan Aeronautics Limited]].<ref name="jawa82 p736">Taylor 1982, p. 736.</ref>

Haworth and his team later went on to design and develop the larger and more powerful [[Rolls-Royce Tyne]].<ref>"World Encyclopedia of Aero Engines – 5th edition" by [[Bill Gunston]], Sutton Publishing, 2006, p.197</ref>