View source for Williams X-Jet

{{Short description|Single-person lightweight aircraft}}
{{No footnotes|date=March 2014}}
[[File:Williams X-Jet.jpg|thumb|300px|right|One of the three original proof-of-concept prototypes of the Williams X-Jet, on display at the Seattle [[Museum of Flight]].]]
[[File:Williams X-Jet - side view.jpg|thumb|right|X-Jet viewed from the side]]

The '''Williams X-Jet''', created by [[Williams International]], was a small, single-person, light-weight, Vertical Take Off and Landing ([[VTOL]]) aircraft powered by a modified [[Williams F107]] [[turbofan]] [[aircraft engine]] — designated WR-19-7 — after some minor modifications. The vehicle was nicknamed "The Flying [[Pulpit]]" for its shape.  It was designed to carry one operator and to be controlled by leaning in the direction of desired travel and by modulating engine output power. It could move in any direction, accelerate rapidly, [[Helicopter flight controls#Hover|hover]] and rotate on its axis, stay aloft for up to 45 minutes and travel at speeds up to 60 miles per hour (97&nbsp;km/h). It was evaluated by the [[United States Army]] in the 1980s, but was deemed inferior to the capabilities of [[helicopter]]s and small, uncrewed aircraft, and so the development of the X-Jet was discontinued.

Other VTOL systems developed by Williams International included a jet-powered flying belt, developed in 1969, which was powered by a [[Williams F107|Williams WR19]] turbofan, and X-Jet's predecessor, the WASP I (Williams Aerial Systems Platform), which was developed in the 1970s and was powered by the more powerful WR19-9 BRP5, rated at 670&nbsp;lbf (2.98 [[Newton (unit)|kN]]) thrust and a [[Thrust specific fuel consumption|specific fuel consumption]] of 0.47&nbsp;lb/lbf·h (13.31 g/kN·s).

{{US patent|4447024}} was issued for the Williams X-Jet. Technical information and drawings are available at the [[United States Patent and Trademark Office]]. The WASP II uses a slightly modified and derated version of the WR-19-A7D, yielding 600&nbsp;lbf thrust from its micro turbofan engine and is designated WR19-7, rated at 570&nbsp;lbf thrust, after minor modifications and said derating. Modifications to the WR-19-A7D included accessories&nbsp;— replacement of pyro starter with electric/air start&nbsp;— and exhaust system modifications. No internal modifications to the counter-rotating micro turbofans were performed. The first crewed, untethered flight was conducted in April 1980. Ray Le Grande is one of the WASP II operators trained by Williams International to fly the X-Jet.

==Specifications (X-Jet)==

{{Aircraft specs
|ref={{citation needed|date=March 2020}}
|prime units?=kts
<!--
        General characteristics
-->
|crew=1
|length ft=3
|length in=
|length note=approx.
|width ft=
|width in=
|width note=
|height ft=4
|height in=0
|height note=
|empty weight lb=401
|empty weight note=
|gross weight lb=550
|gross weight note=
|max takeoff weight lb=
|max takeoff weight note=
|fuel capacity=
|more general=
<!--
        Powerplant
-->
|eng1 number=1
|eng1 name=[[Williams F107]]
|eng1 type=[[turbofan]] engine
|eng1 lbf=570
|eng1 note=(modified)
<!--
        Performance
-->
|max speed kts=52
|max speed note=
|max speed mach=<!-- supersonic aircraft -->
|cruise speed kts=
|cruise speed note=
|never exceed speed kts=
|never exceed speed note=
|range nmi=
|range note=
|ferry range nmi=
|ferry range note=
|endurance=30–45 minutes
|ceiling ft=10000
|ceiling note=
|climb rate ftmin=
|climb rate note=
|time to altitude=
|wing loading lb/sqft=
|wing loading note=
|fuel consumption lb/mi=
|thrust/weight=1.11

|more performance=

|avionics=
}}

==See also==
{{Aircontent|
| related = <!-- related developments -->
| similar aircraft = 
* [[Hiller VZ-1 Pawnee]]
}}

==Notes==
{{Reflist}}

==References==
* Display information at [[Museum of Flight]] in [[Seattle, Washington]].
* [https://www.theguardian.com/science/2000/sep/14/technology2 Guardian article]
* [https://www.nationalmuseum.af.mil/ nationalmuseum.af.mil]
* ''The History of North American Small Gas Turbine Aircraft Engines'', by Richard A. Leyes II and William A. Fleming ({{ISBN|1-56347-332-1}} Copyright 1999)

[[Category:1970s United States experimental aircraft]]
[[Category:Flying platforms]]
[[Category:VTOL aircraft]]
[[Category:Williams aircraft|X-Jet]]
[[Category:Standing pilot aircraft]]