Editing Napier Nomad (section)

{{Short description|British diesel aircraft engine}}
{{Use dmy dates|date=October 2019}}
{{Use British English|date=December 2017}}
{|{{Infobox aircraft begin
 |name = Nomad
 |image= File:Napier Nomad.jpg
 |caption= Napier Nomad II
}}{{Infobox Aircraft Engine
 |type=[[Turbo-compound]]<br> [[aircraft engine|aero-engine]]
 |national origin=United Kingdom
 |manufacturer=[[Napier & Son]]
 |first run=[[1949 in aviation#October|October 1949]]
 |major applications=[[Avro Lincoln]] (test bed only)
 |number built = 
 |program cost = £5.1 million
 |unit cost = 
 |developed from = 
 |developed into = 
 |variants with their own articles = 
}}
|}

The '''Napier Nomad''' is a British [[diesel engine|diesel]] [[aircraft engine]] designed and built by [[Napier & Son]] in 1949. They combined a [[piston engine]] with a [[turbine]] to recover energy from the exhaust and thereby improve [[fuel efficiency|fuel economy]]. Two versions were tested, the complex '''Nomad I''' which used two propellers, each driven by mechanically independent stages, and the '''Nomad II''', using the turbo-compound principle which coupled the two parts to drive a single propeller. The Nomad II had the lowest [[specific fuel consumption (shaft engine)|specific fuel consumption]] figures seen up to that time.<ref name="Gunston, Encyc. Aero Engines, p106" >{{cite book
  |last=Gunston  |first=Bill  |authorlink=Bill Gunston
  |title=World Encyclopaedia of Aero Engines
  |location=Cambridge, England  |publisher=Patrick Stephens 
  |year=1989
  |isbn=1-85260-163-9
  |ref=Gunston, Encyc. Aero Engines
  |page=106
}}</ref> Despite this the Nomad project was cancelled in 1955 having spent £5.1 million on development, as most interest had passed to [[turboprop]] designs.<ref name="Flight, 17 August 1967, Cancelled projects list" >{{cite journal
  |journal=[[Flight (magazine)|Flight]] 
  |title=Cancelled projects: the list up-dated
  |url=http://www.flightglobal.com/pdfarchive/view/1967/1967%20-%201672.html
  |date=17 August 1967
  |page=262
  |ref=Flight, 17 August 1967, Cancelled projects list
  |url-status=dead
  |archive-date=March 5, 2016
  |archive-url=https://web.archive.org/web/20160305152115/https://www.flightglobal.com/pdfarchive/view/1967/1967%20-%201672.html
}}</ref>