Editing Lockheed X-7 (section)

==Early development==
Development of the Kingfisher was first initiated in December 1946. The X-7 was called into production by the United States Air Force requirement for the development of an unmanned ramjet test plane with a top speed of at least {{convert|3|Mach|altitude_ft=40000}}.<ref name=":13">{{Cite web|url=http://www.designation-systems.net/dusrm/m-60.html|title=Lockheed AQM-60 Kingfisher|website=www.designation-systems.net|access-date=2017-04-09}}</ref>

The X-7 project was developed under the AMC designator MX-883 and was given in the Lockheed in-house designation L-171. The L-171 was initially designated the '''PTV-A-1''' by the USAF but was later designated the X-7 in 1951.<ref name=":13" />  Despite its first launch being a failure, after re-development of the original ramjet, following test flights were successful.<ref name=":06">{{Cite web|url=http://www.456fis.org/LOCKHEED_X-7.htm|title=The Lockheed X-7|website=www.456fis.org|access-date=2017-04-09|archive-date=2018-05-19|archive-url=https://web.archive.org/web/20180519003015/http://www.456fis.org/LOCKHEED_X-7.htm|url-status=usurped}}</ref> A total of 130 X-7 flights were conducted from April 1951 to July 1960.<ref name=":06"/>