Thursday, July 16, 2009

B-2's First Flight: Another Aerospace Anniversary

While the 40th anniversary of Apollo 11's mission to the Moon is being widely (and rightfully) commemorated this week, another important event in aerospace is being remembered, perhaps not as widely as it should be.
Tomorrow, July 17th, is the 20th anniversary of the first flight of the B-2.
Now, if this was just another airplane of the type that been built for decades, and in the same manner as those before it, with the same capabilities, the anniversary would logically be only of interest perhaps to those who helped make it happen, or those who witnessed it, or the aficionados of all things aerospace. But the B-2 WAS different, it's birth and design was brought about differently that any airplane before it, and the path to its first flight was different than all of those that came before it as well - and computing tools made it all possible . I want to note on just two of the ways the B-2 changed the game.
Design and Build Process
It was the first major aircraft that was created using Computer Aided Design as the primary means of design and rendering. At about the time the B-2 was being conceived, I was visiting a British Aerospace plant in Hatfield, England where one could view the engineering building from the Motorway and see through several floors of nothing but rows of drafting tables and vellum. B-2 airframe parts were designed and built in different regions of the United States by different companies-- and when the parts were brought together for the first time, they had to mate with exacting (compared to predecessors) tolerances. What is now a design and build process that is routinely practiced around the world was first applied on such a major scale on the design of the B-2.
Giant Steps: Building Without Prototyping
The very first B-2 built had to possess the most important design feature of the B-2: STEALTH. This meant the tolerances, materials, and design of the first plane had to be representative of the final product. This in turn meant that the standard process of mocking up a prototype on temporary tooling and testing how the design flew wouldn't answer the most important questions that needed answering. Thus, the first B-2 was built with production tooling from the start. This is one of the biggest, if not THE biggest, reason the unit cost of the limited number of B-2s built is usually cited so high (typically $1-2B a copy). Note: For perspective, I always ask people who point out the B-2's unit cost what do they think the price of their car would be if the company that made it put everything into place to build it and then only built ONE car.

Oh, Those Nattering Nabobs of Negativity
Since the B-2 has flown for 20 years, it is easy to forget now how controversial the decision to NOT build a prototype was, and how much fear there was in some quarters (usually by people who had no idea of the advances in Computational Fluid Dynamics (CFD) that had occurred) that building such an unconventional design without prototyping was madness!

Some examples of nay saying, from a May 1989 Philadelphia Inquirer article (scroll down at link to find) published before the B-2's first flight serve this point well. I've interspersed some of my observations on how off-target and off-the-wall program outsiders can be in [brackets], for a reason to be revealed at the end. You might notice one or two of the names are still around making doom and gloom commentary:
"I think the B-2 will crash the first time it flies," said Kosta Tsipis, director of the Program in Science and Technology for International Security at the Massachusetts Institute of Technology." I wouldn't be a passenger aboard it for anything in the world."
[ I SERIOUSLY doubt Dr Tsipis was applying any of his mathematics or physics education in that statement. I think we can chalk his faux fear up to what I like to identify as 'Intellect held captive byIdeology' ]
"A $70 billion program with no prototypes?" asked an incredulous Thomas S. Amlie, an Air Force engineer at the Pentagon, who said computers and models could not replicate the rigors of flight. "Of course we should prototype. We ought to fly one, and wring the hell out of it, with zero-zero ejection seats so the pilots can eject at zero altitude and zero air speed and live through it."
[Amlie was pretty long in the tooth at the time of the article and I question whether or not he really understood how far computing in general and CFD specifically had come in the very short time leading up to the conception of the B-2. Call this an example of an out-of-the-loop 'expert'. Oh and the B-2 WAS designed with zero-zero seats, BTW- as pilots unfortunately had to recently demonstrate in Guam.]
Amlie dismissed Air Force arguments that there were classified reasons why prototyping the B-2 makes no sense. "They always say there are classified things that we can't know about because we don't have the clearance," Amlie said. "Well, I've been in the business for 37 years, and every time someone has told me that it turns out they were lying."
[I'm sure Amlie was/is pleased to know no one was lying to him THIS time. Amlie, BTW is best known for stinking up the Pentagon with rants against so-called "revolving-door" Contractor-Government relationships back in the late 70s-early 80's. POGO and their ilk loved him.]
"Given all the aerodynamic and performance compromises they've had to make to reduce the radar cross-section of the B-2, you're just flying much closer to the margin," said [John] Pike of the Federation of American Scientists. "That's precisely why you need to do prototyping."
[Pike is 'interesting' here. This quote is from before I knew anything about him at FAS and way long before he left them and started Global Security. These days, he's usually very careful to not go too far out on a limb when it comes to defense technology claims. Here he makes assertions unsupported by fact. Aerodynamics are always an area of compromise, but no more closer to the 'margins' because of stealth in the B-2's case. Performance? The B-2 is S***Hot in its flight regime, so WTFO? Mr Pike, you were talking through your hat.]
"It's very strange that they're not being required to prototype," added Joseph V. Foa, an aeronautical engineer at George Washington University who first studied flying wings 40 years ago. "When you have an aircraft that's going to cost a half-billion dollars apiece, it's a good idea to prototype.
[Dr. Foa's history with Northrop and flying wing design reads like a melodrama. I think he picked a bone with Theodore Von Karmann about 1946 and kept picking until the day he died. The reasons why are fascinating and I think worthy of a peer-reviewed history paper. At the time he was quoted here, he had been getting his words of woe about the flying wing out via an underachieving EE-cum-Pulitzer journalist (now-GASP-teaching at JHU) named Wayne Biddle, and by publishing in a Canadian aerospace journal. Foa, though quite learned and I think worthy even of study in areas related to jet propulsion, was IMHO very much a non-sequitur in the field of aircraft conceptual design. He was the personification of that equal and opposite PhD my friend Dr Paul regularly warns me about]
Pike said recurring delays -- the plane's first flight originally was set for 1987 -- showed that Northrop's computers had not eliminated the B-2's problems. "That tells me this thing is no different from anything else," he said. "Just because it looks right on the computer screen doesn't mean that it's going to work in the real world."
[Mr Pike is NOW hopefully aware that the two year delay was caused by a redesign driven by the AF radically changing the requirements when the initial design was half-way done. This may be about the time Mr Pike started thinking like a Defense POLICY Expert instead of 'Defense Expert'. ].
Why Revisit Old Criticisms?
The biggest lesson to take from this review of history is not that the naysayers were wrong. It is that they could have been right, but it would have been purely by accident. The naysayers of today's weapons procurements are no different than those who were sounding the (what turned out to be) false alarms then. They are almost certainly wrong. But if they're right, it only proves the old adage that "even a blind pig finds an acorn now and then" is a truism.
Outside pundits don't KNOW diddly. Never have. Never will.
Happy Anniversary B-2!

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