Editing Lockheed Have Blue (section)

=== Design effort and early testing ===
Lockheed, having been absent from the fighter aircraft industry for 10 years, was not approached by DARPA in 1974. Ed Martin, Lockheed California Companies director of science and engineering, became aware of the research into stealth during his work at [[the Pentagon]] and [[Wright-Patterson AFB]].<ref name=Crickmore_p10>Crickmore 2003, p.&nbsp;10.</ref> Martin and [[Ben Rich (engineer)|Ben Rich]], who at that time had recently become [[Skunk Works]]' president, briefed [[Kelly Johnson (engineer)|Clarence "Kelly" Johnson]] on the program. The [[Central Intelligence Agency]] (CIA) gave Skunk Works permission to discuss with DARPA the stealth characteristics of the [[Lockheed A-12|A-12, M-21 and D-21]].<ref name=Crickmore_p10 /> On behalf of the company, Rich and Martin formally requested permission from DARPA to participate in the program, but the agency initially refused because there were insufficient funds; after much debate, Lockheed was allowed entry, albeit without a government contract.<ref name=Crickmore_p10 />
[[File:ClarenceLeonardKellyJohnson.jpg|thumb|[[Kelly Johnson (engineer)|Kelly Johnson]], Lockheed's designer, was initially skeptical of the ''Have Blue'' project]]

Preliminary designer [[Richard C. Scherrer|Dick Scherrer]] requested possible shapes upon which he could base his low [[radar cross-section]] (RCS) design. He was introduced to Denys Overholser,<ref>{{cite web|author=Capi Lynn|date=16 April 2016 |title=Secret weapon for stealth tech is from Dallas |url=https://www.statesmanjournal.com/story/news/2016/04/16/secret-weapon-stealth-tech-dallas/82678480/|access-date=2016-04-19 |website=Statesman Journal}}</ref> who recommended an aircraft with flat surfaces. Overholser later recounted his discussion with Sherrer: "When Dick Scherrer asked me ... I said 'Well, it's simple, you just make it out of flat surfaces, and tilt those flat surfaces over, sweeping the edges away from the radar view angle, and that way you basically cause the energy to reflect away from the radar.'"<ref name=Crickmore_p11>Crickmore 2003, p.&nbsp;11.</ref> Scherrer subsequently drew a preliminary low-RCS aircraft with faceted surfaces.<ref name=Crickmore_p11 /> At the same time, Overholser hired mathematician Bill Schroeder, with whom he had a prior working relationship – in fact, it was Schroeder who trained Overholser on mathematics relating to stealth aircraft.<ref name=Crickmore_p11 /> Kenneth Watson was hired as the senior lead aircraft designer.<ref name=Crickmore_p11 />

During the next few weeks, the team created a computer program which could evaluate the RCS of possible designs. The RCS-prediction software was called "ECHO 1". As tests with the program proceeded, it became apparent that edge calculations by the program were incorrect due to [[diffraction]].<ref name=Crickmore_p11 /> To overcome this, Overholser incorporated elements of research by Soviet engineer [[Pyotr Ufimtsev]] into the software.<ref name=Crickmore_p11 /><ref>Jenkins 1999, p.&nbsp;16.</ref> (In 1962, Ufimtsev, as chief scientist of the Moscow Institute for Radio Engineering, published a seminal paper titled ''Method of Edge Waves in the Physical Theory of Diffraction''. The work had been translated by the US [[Air Force Systems Command]]'s Foreign Technology Division.<ref>Ufimtsev 1962.</ref>)
ECHO 1 allowed the team to quickly decide which of the 20 possible designs were optimal, finally settling on the faceted delta-wing design.<ref name=Crickmore_p12>Crickmore 2003, p.&nbsp;12.</ref> However, many within the division were skeptical of the shape, giving rise to the name "Hopeless Diamond"<ref name=Sweetman_p25>Sweetman 2005, p.&nbsp;25.</ref>&nbsp;– Kelly Johnson said to Rich, "Our old [[Lockheed D-21|D-21]] drone has a lower radar cross-section than that goddamn diamond".<ref name=Crickmore_p12 />

In May 1975, the Skunk Works produced an internal report titled, "Progress Report No. 2, High Stealth Conceptual Studies." Within it was a concept study called "Little Harvey," including Kelly Johnson's drawing of an aircraft with smoothly blended shapes. Johnson advocated for the use of blended shapes as the best way to achieve stealth, while Ben Rich advocated for faceted angles. Rich won the argument with Johnson, a rare occurrence.<ref>Slattery, Chad, "Secrets of the Skunk Works," ''Air & Space'', August 2014, p. 41</ref>

The design effort produced a number of wooden models. A 24-inch long model, made of [[balsa wood]], demonstrated placement of internal structure and access doors. An ''Air & Space'' article noted "The model shop found it nearly impossible to make all the flat surfaces come to a single point in one corner. Engineers later encountered the same difficulty fabricating the prototype on the factory floor."<ref>Slattery 2014, p. 43</ref> For early tests of the design, two ⅓-scale wooden mock-ups were constructed. One model, coated in metal foil, was used to verify ECHO 1's RCS calculations, while the other was earmarked for wind tunnel tests.<ref name=Crickmore_p12 /><ref name=HB_FTP>{{cite web|title=Have Blue Flight Test Program|website=GlobalSecurity.org |url=http://www.globalsecurity.org/military/systems/aircraft/have-blue-flight.htm|access-date=31 July 2011}}</ref> Afterwards, a model was moved to the [[Grey Butte Range]] radar-testing facility in the [[Mojave Desert]] near [[Palmdale]], which allowed more accurate tests of the aircraft's RCS. In the event, the aircraft's RCS level confirmed ECHO 1's predictions.<ref name=Crickmore_p12 /> This meant Ben Rich won a [[Quarter (United States coin)|quarter]] from Johnson, who previously insisted that the D-21 had less RCS than ''Have Blue''.<ref name=Crickmore_p12 />