Boeing Bird of Prey Demonstrator

A gull wing configuration for tailless aircraft stability & control was patented by Grumman-Bethpage in 1996, filed in 1993*.
Grumman had been shopping around an unclassified flight demonstrator concept using an X-29A to NASA, AF and DARPA, to no avail.
[*Rich Nastasi conceived of the idea in 1987 or 1988 in a classified environment; I know firsthand.]
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Grumman didn't file for the patent until a year after McDonnell Douglas-St Louis 'reportedly' began work on Bird of Prey.
Guess#1 is that Rich's concept was wind tunnel tested in 1988 or 1989, and the results made their way into the sanitized technology-leveling library administered by the LO/CLO EXCOM. McAir, AF and/or NASA became aware, and adopted it.
Guess#2 is that McAir cooked up the gull-wing control effector configuration themselves -- nothing new under the sun, as they say.
I lean to Guess#1, owing to some technology transfer shenanigans I'm aware of with the nozzle design on Bird of Prey and the near-concurrent X-36.
 

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They did BOP on a tight budget and with the gull-wing configuration, the aircraft had mechanical flight control system, no hydraulic fly-by-wire/artificial stability, would have cost a lot more. Even with the gull-wing configuration, it could be a hand full for the pilot in certain flight regimes. But BOP demonstrated and proved out what they wanted to accomplished so it was a successful program.

The gull-wing shape could have compromised LO possibly but LO is not my area of expertise.

As an example, there was no way Tacit Blue could have flown without a FBW flight control system, it would be the Tacit Tumbler, not good, same goes for the YF-23, plus from what I was told, Tacit Blue was unstable in all 3 axis. You can add F-16 and F-117 to the list as well which could not fly with a pure mechanical control system even with hydromechanical assist.
 
I love how many images there are of every classified aircraft we know of, before declassification, taken midday and from a lower altitude.
 
Hansblix said:
I love how many images there are of every classified aircraft we know of, before declassification, taken midday and from a lower altitude.
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All aircraft are first flown in daylight JIC there's an emergency. I'm not sure why this is so surprising. They know if anyone is watching out at the test ranges, so they just schedule accordingly.
 
Sundog said:
All aircraft are first flown in daylight JIC there's an emergency. I'm not sure why this is so surprising.
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Amen, brother. Making the maiden flight in daylight is generally necessary from a safety standpoint as well as for engineering documentation. The F-117A, which was specifically designed to operate in darkness, didn't start doing nighttime test sorties until its basic flight characteristics and handling qualities had been verified. That said, the "RQ-180" made "the only nighttime first flight in the history of aviation" as an extra security measure to prevent unauthorized persons from seeing the aircraft.
 
"the only nighttime first flight in the history of aviation"

Exactly. That is hilarious.

Y'all need to lighten up!
 
quellish said:
There has been nothing definitive published, of course.
But it can be reasonably inferred that the signature is significantly lower. According to people familiar with the program, the visual signature became dominant - it could be seen with the eyeball before it could be seen using radar. The visual signature was then reduced by several means, and this was one of the primary goals of the project.
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Ho Lee Fook! That's a ghost and a half!
 
Was there any synthesis of the learnings from YF-118G and X-36? Both were tailless and LO, but explored different particulars of flight and signature reduction.
 
I wonder how much of the stealth technology from the Bird of Prey went into the F-47 since the BOP was THE stealthiest aircraft ever built. I also cannot belive that it has been thirty years since the Bird of Prey first flew.
 
On Linkedin, I've got the feedback by Doug "Benj" Benjamin the then Boeing test pilot for the BoP program, amazing!
 

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