Editing Jet engine (section)

==== Propfan ====
{{Main article|Propfan}}
A [[propfan]] engine is a type of airbreathing jet engine which combines aspects of [[turboprop]] and [[turbofan]]. Its design consists of a central gas turbine which drives open-air [[contra-rotating propellers]]. Unlike turboprop engines, in which the propeller and the engine are considered two separate products, the propfan’s gas generator and its unshrouded propeller module are heavily integrated and are considered to be a single product. {{Citation needed|date=November 2024}} Additionally, the propfan’s short, heavily twisted [[Variable-pitch propeller (aeronautics)|variable pitch]] blades closely remember the ducted fan blades of turbofan engines.

Propfans are designed to offer the speed and performance of turbofan engines with fuel efficiency of turboprops. However, due to low fuel costs and high cabin noise, early propfan projects were abandoned.<ref>{{Cite web |last=Flight International (2007-07-12). |title=Whatever happened to propfans? |url=https://www.flightglobal.com/whatever-happened-to-propfans/74180.article |url-status=live |archive-url=https://web.archive.org/web/20071020123934/http://flightglobal.com/articles/2007/06/12/214520/whatever-happened-to-propfans.html |archive-date=October 20, 2007 |access-date=2024-11-28 |website= |language=en}}</ref> Very few aircraft have flown with propfans, with the [[Antonov An-70]] being the first and only aircraft to fly while being powered solely by propfan engines.