[ianstallings]

Yes and what is strange is it isn't faceted like the F-117, which Lockheed was making during the same era. As far as I can recall Ben Rich said that he had stumbled on a paper by a Russian scientist regarding how to defeat radar using various angles. But their limited computation capability led Lockheed to create a faceted design instead of a round one. One has to wonder why Boeing didn't do that. Was it just guess work? Or was it some information-sharing between the two groups and Boeing simply took a different, yet better approach?

Northrop's Tacit Blue might have been the influencer for both programs: https://en.wikipedia.org/wiki/Northrop_Tacit_Blue

[edwhitesell]

Well, the Hopeless Diamond (F-117 model) was 15 years _after_ this plane. This plane clearly had some of the early thoughts on lowering RCS though, similar to the SR-71 Blackbird.

There were no facets on this plane because that really only came about after Ufimtsev's paper described how to calculate RCS. Computers at the time of the Hopeless Diamond/Have Blue/F-117 couldn't run those calculations on curved surfaces. Which meant Ben Rich's team used the flat surfaces (I don't recall exactly who suggested it, but it's in the book).

I'd also be curious if Boeing had any thoughts in the areas of radar absorbtion/dispersing paint in the 60s. I recall the SR-71 Blackbird had some of those properties in it's paint (though the paint was mainly used for cooling).

[vonmoltke]

As mentioned in the article, Boeing did this work two years before Ufimtsev even published his paper. It was also a full ten years before Lockheed even started designing the F-117.

[ianstallings]

Sorry I missed the article, I thought it was just an image gallery and had to scroll down through a strange(imho) layout. Thanks!