This was calculated by hand by Skunk Works engineers. They didn't have the benefit of computerized physical modeling back then.
Half true.
Stealth had been known to be theoretically possible [edit] for a long time. I want to say the critical ideas date to papers in the 1930's, but I'm not sure on that. I do know there were flying attempts at it in the 40's. [/edit] But nobody could really pull it off due to the sheer computation required.
Stealth happened when computers got good enough. The critical breakthrough was a computer program. Not a full blown physical model, mind you; a very specific program to solve a very specific mathematical problem created by a very clever mathematician.
In early 1975, the initial Skunk Works Project Team
consisted of Ed Martin (Project Manager), Dick Schemer
and Denys Overholser. Overholser had recalled a
discussion with his then boss, Bill Schroeder, some years
earlier, concerning the mathematics and physics of
optical scattering. The two had concluded that detectable
signatures could be minimized utilizing a shape composed
of the smallest number of properly orientated flat
panels. In addition, Schroeder believed that it was
possible to develop and resolve a mathematical equation
capable of calculating analytically, the reflection from
a triangular flat panel; this in turn he hypothesized
could be applied in a calculation relating to RCS.
Overholser had hired his former boss out of retirement
and as Schroeder's mathematical computations became
available, Overholser and his team of two engineers were
able to use these to write the computer program that
could evaluate the RCS of prospective design submissions
nominated by Dick Scherrer and his group of preliminary
design engineers. Derys and his team worked night and
day, and in just five weeks produced an RCS prediction
program known as 'Echo 1'. The resultant model was a
faceted delta wing design which had more than its share
of skeptics within the Skunk Works, some in aerodynamics
referring to the shape as 'the Hopeless Diamond'.
The computer's were important not just for calculating the shape of the airframe, but how to fly the damn thing. You could in theory calculate the F-117 (but not the B2's) frame by hand. But flying the F-117 -or any stealth airframe - requires computer guidance.
In act, the prototype (Have Blue) just recycled some extra flight computers from the F-16 (which is unstable in one axis... the F-117 is unstable in all three).
Half true.
Stealth had been known to be theoretically possible [edit] for a long time. I want to say the critical ideas date to papers in the 1930's, but I'm not sure on that. I do know there were flying attempts at it in the 40's. [/edit] But nobody could really pull it off due to the sheer computation required.
Stealth happened when computers got good enough. The critical breakthrough was a computer program. Not a full blown physical model, mind you; a very specific program to solve a very specific mathematical problem created by a very clever mathematician.
But a computer program nonetheless.
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http://www.456fis.org/F-117_STORY.htm
[Edit: Fact check]