Editing Lockheed Have Blue (section)

{{short description|Experimental stealth aircraft}}
{{Use dmy dates|date=September 2020}}
{{DISPLAYTITLE:Lockheed ''Have Blue''}}
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{{Infobox aircraft
|name=''Have Blue''
|image= File:DARPA USAirForce HaveBlue.png
|caption=''Have Blue'' "HB1001" in camouflage paint scheme
|type=[[Stealth aircraft|Stealth demonstrator]]
|manufacturer=[[Lockheed Corporation|Lockheed]] [[Skunk Works]]
|designer=
|first_flight=1 December 1977
|introduction=
|retired=
|produced=
|number_built=2
|status=Destroyed
|program cost={{AircraftCost|USA|35|m|year=1978|ref=<ref>Goodall 1992, p.&nbsp;19.</ref>}}
|primary_user=[[Lockheed Corporation|Lockheed]]
|more_users=
|developed_from=
|variants=
|developed_into=[[Lockheed F-117 Nighthawk]]
}}

'''Lockheed ''Have Blue''''' was the code name for [[Lockheed Corporation|Lockheed]]'s [[proof of concept]] demonstrator for a stealth fighter. ''Have Blue'' was designed by Lockheed's [[Skunk Works]] division, and tested at [[Groom Lake]], [[Nevada]]. The ''Have Blue'' was the first [[fixed-wing aircraft]] whose external shape was defined by [[radar]] engineering rather than by [[aerospace engineering]]. The aircraft's [[faceting|faceted]] shape was designed to deflect [[Electromagnetic radiation|electromagnetic waves]] in directions other than that of the originating [[radar]] emitter, greatly reducing its [[radar cross-section]].

To design the aircraft, the Skunk Works' design team leveraged the mathematics published by Soviet physicist and mathematician [[Petr Ufimtsev]] regarding the reflection of electromagnetic waves.<ref>{{cite web|url=http://www.larrymusa.com/Physicists/ufimtsev.aspx |title=Physicist of the Week: Pyotr Ufimtsev|access-date=2009-01-15 |website=www.larrymusa.com|archive-url=https://web.archive.org/web/20090224070038/http://www.larrymusa.com/Physicists/ufimtsev.aspx|archive-date=2009-02-24|url-status=dead}}</ref> A stealth engineer at Lockheed, Denys Overholser, had read the publication and realized that Ufimtsev had created the mathematical theory and tools to perform finite element analysis of radar reflection.<ref>{{cite web |url=http://dsc.discovery.com/convergence/stealth/article/article.html|title=The F117A – A Secret History|access-date=2009-01-15|author=Patrick Kiger|publisher=Discovery Channel}}</ref>

The eventual design characteristically featured faceted surfaces to deflect radar waves away from a radar receiver. It had highly [[Swept wing|swept]] wings and inward-canted [[vertical stabilizer]]s, which led to it being nicknamed "the Hopeless Diamond"—a pun on the [[Hope Diamond]]. The first operational aircraft made its [[maiden flight]] on 1 December 1977.

Two flyable vehicles were constructed. Both were lost due to mechanical problems. Nevertheless, ''Have Blue'' was deemed a success, paving the way for the first operational stealth aircraft, ''Senior Trend'', or [[Lockheed F-117 Nighthawk]].