by Ben R Rich
“Ufimtsev has shown us how to create computer software to accurately calculate the radar cross section of a given configuration, as long as it’s in two dimensions,” Denys told me. “We can break down an airplane into thousands of flat triangular shapes, add up their individual radar signatures, and get a precise total of the radar cross section.”
Why only two dimensions and why only flat plates? Simply because, as Denys later noted, it was 1975 and computers weren’t yet sufficiently powerful in storage and memory capacity to allow for three-dimensional designs, or rounded shapes, which demanded enormous numbers of additional calculations. The new generation of supercomputers, which can compute a billion bits of information in a second, is the reason why the B-2 bomber, with its rounded surfaces, was designed entirely by computer computations.
Denys’s idea was to compute the radar cross section of an airplane by dividing it into a series of flat triangles. Each triangle had three separate points and required individual calculations for each point by utilizing Ufimtsev’s calculations. The result we called “faceting”—creating a three-dimensional airplane design out of a collection of flat sheets or panels, similar to cutting a diamond into sharp-edged slices.
As his boss, I had to show Denys Overholser that I was at least as intellectual and theoretical as Ufimtsev,* so I strummed on my desk importantly and said, “If I understand you, the shape of the airplane would not be too different from the airplane gliders we folded from looseleaf paper and sailed around the classroom behind the teacher’s back.”
Denys awarded me a “C+” for that try.
The Skunk Works would be the first to try to design an airplane composed entirely of flat, angular surfaces. I tried not to anticipate what some of our crusty old aerodynamicists might say. Denys thought he would need six months to create his computer software based on Ufimtsev’s formula. I gave him three months. We code-named the program Echo I. Denys and his old mentor, Bill Schroeder, who had come out of retirement in his eighties to help him after serving as our peerless mathematician and radar specialist for many years, delivered the goods in only five weeks. The game plan was for Denys to design the optimum low observable shape on his computer, then we’d build the model he designed and test his calculations on a radar range.
In those early days of my tenure at the Skunk Works, Kelly Johnson was still coming in twice a week as my consultant as part of his retirement deal. I had mixed feelings about it. On the one hand, Kelly was my mentor and close friend, but it pained me to see so many colleagues crowding into his small office down the hall from mine, taking their work problems to him instead of to me. Of course, I really could not blame them. No one in our shop came close to possessing Kelly’s across-the-board technical knowledge, but he didn’t just limit himself to providing aerodynamic solutions for stumped engineers; he damned well wanted to know what I was up to, and he wasn’t exactly shy about firing off opinions, solicited or not. After a quarter century of working at his side, I knew Kelly’s views nearly as well as my own, and I also knew that he would not be thrilled about stealth because he thought the days of manned attack airplanes were definitely numbered. “Goddam it, Ben, the future belongs to missiles. Bombers are as obsolete as the damned stagecoach.”
I argued back, “Kelly, the reason they call them missiles, instead of hittles, is that they miss much more than they hit.” But Kelly just shook his head.
Several years earlier, we had built a pilotless drone, the D-21, a forty-four-foot manta ray–shaped ramjet that was launched from B-52 bombers to streak high across Communist China and photograph its nuclear missile test facilities. That drone achieved the lowest radar cross section of anything we had ever built in the Skunk Works, and Kelly suggested that we offer our D-21 to the Air Force as a radar-penetrating attack vehicle, with or without a pilot. I put together a small team to begin a modification design, but I couldn’t stop thinking about stealth.
That first summer of my takeover, our in-house expert on Soviet weapons systems, Warren Gilmour, attended a meeting at Wright Field, in Ohio, and came back in a dark mood. He marched into my office and closed the door. “Ben, we are getting the shaft in spades,” he declared. “One of my friends in the Tactical Air Command spilled the beans. The Defense Department’s Advanced Research Projects Agency has invited Northrop, McDonnell Douglas, and three other companies to compete on building a stealthy airplane. They’re getting a million bucks each to come up with a proof of concept design, trying to achieve the lowest radar signatures across all the frequencies. If one works, the winner builds two demonstration airplanes. This is right up our alley and we are being locked out in the goddam cold.”
This was exactly the kind of project I was looking for. But we had been overlooked by the Pentagon because we hadn’t built a fighter aircraft since the Korean War and our track record as builders of low-radar-observable spy planes and drones was so secret that few in the Air Force or in upper-management positions at the Pentagon knew anything about them.
Warren read my mind. “Face it, Ben, those advanced project guys don’t have a clue about our spy plane work in the fifties and sixties. I mean, Jesus, if you think racing cars, you think Ferrari. If you think low observables, you must think Skunk Works.”
Warren was absolutely right. The trouble was getting permission from our spy plane customer, that legendary sphinx known as the Central Intelligence Agency, to reveal to the Pentagon’s competition officials the low observable results we achieved in the 1960s building the Blackbird, which was actually the world’s first operational stealth aircraft. It was 140,000 pounds and 108 feet long, about the size of a tactical bomber called the B-58 Hustler, but with the incredibly small radar cross section of a single-engine Piper Cub. In other words, that is what a radar operator would think he was tracking. Its peculiar cobra shape was only part of the stealthy characteristics of this amazing airplane that flew faster than Mach 3 and higher than 80,000 feet. No one knew that its wings, tail, and fuselage were loaded with special composite materials, mostly iron ferrites, that absorbed radar energy rather than returning it to the sender. Basically 65 percent of low radar cross section comes from shaping an airplane; 35 percent from radar-absorbent coatings. The SR-71 was about one hundred times stealthier than the Navy’s F-14 Tomcat fighter, built ten years later. But if I knew the CIA, they wouldn’t admit that the Blackbird even existed.
Kelly Johnson was regarded almost as a deity at the CIA, and I had him carry our request for disclosure to the director’s office. To my amazement, the agency cooperated immediately by supplying all our previously highly classified radar-cross-section test results, which I sent on to Dr. George Heilmeier, the head of DARPA (the Defense Department’s Advanced Research Projects Agency), together with a formal request to enter the stealth competition. But Dr. Heilmeier called me, expressing regrets. “Ben, I only wish I had known about this sooner. You’re way too late. We’ve given out all the money to the five competitors.” The only possibility, he thought, would be to allow us to enter if we would agree to a one dollar pro forma government contract. As it turned out, if I had done nothing more that first year than refuse that one dollar offer, I had more than earned my salary. I was sitting on a major technological breakthrough, and if I took that government buck, the Feds would own the rights to all our equations, shapes, composites—the works. Lockheed was taking the risks, we deserved the future profits.
It took a lot of arguing at my end, but Dr. Heilmeier finally agreed to let us into the stealth competition with no strings attached, and it was the only time I actually felt good about not receiving a government contract. But not Kelly. “You’re wasting your time,” he told me. “This is like chasing a butterfly in a rain forest because in the end the government won’t invest big dollars in stealth, when for the same money they can invest in new missiles.”
In part, I think, Kelly was trying to be protective. He didn’t want me to risk an embarrassing failure my first turn at bat, pursuing a high-risk project with
little apparent long-range potential. I would be spending close to a million dollars of our own development money on this project, and if Kelly was right, I’d wind up with nothing to show for it. Still, I never waivered from believing that stealth could create the biggest Skunk Works bonanza ever. It was a risk well worth taking, proving a technology that could dominate military aviation in the 1980s even more than the U-2 spy plane had impacted the 1950s. At that point the Russians had no satellites or long-range airplanes that could match our missions and overfly us. Stealth would land the Russians on their ear. They had no technology in development that could cope with it. So I resolved to see this project through, even if it meant an early fall from grace. My department heads would go along because they loved high-stakes challenges, with most of the risks falling on the boss. I confided my stealth ambitions to Lockheed’s new president, Larry Kitchen, who was himself dancing barefoot on live coals while trying to pull our corporation up to a standing position after the pulverizing year and a half of scandals and bankruptcy. Larry cautioned me: “We need real projects, not pipedreams, Ben. If you’ve got to take risks, at least make sure you keep it cheap, so I can back you without getting my own head handed to me. And if something goes sour, I want to be the first to know. My blessings.” Good man, Larry Kitchen. After all, he had also approved hiring me as Kelly’s successor.
Denys Overholser reported back to me on May 5, 1975, on his attempts to design the stealthiest shape for the competition. He was wearing a confident smile as he sat down on the couch in my office with a preliminary designer named Dick Scherrer, who had helped him sketch out the ultimate stealth shape that would result in the lowest radar observability from every angle. What emerged was a diamond beveled in four directions, creating in essence four triangles. Viewed from above the design closely resembled an Indian arrowhead.
Denys was a hearty outdoorsman, a cross-country ski addict and avid mountain biker, a terrific fellow generally, but inexplicably fascinated by radomes and radar. That was his specialty, designing radomes—the jet’s nose cone made out of noninterfering composites, housing its radar tracking system. It was an obscure, arcane specialty, and Denys was the best there was. He loved solving radar problems the way that some people love crossword puzzles.
“Boss,” he said, handing me the diamond-shaped sketch, “Meet the Hopeless Diamond.”
“How good are your radar-cross-section numbers on this one?” I asked.
“Pretty good.” Denys grinned impishly. “Ask me, ‘How good?’ ”
I asked him and he told me. “This shape is one thousand times less visible than the least visible shape previously produced at the Skunk Works.”
“Whoa!” I exclaimed. “Are you telling me that this shape is a thousand times less visible than the D-21 drone?”
“You’ve got it!” Denys exclaimed.
“If we made this shape into a full-size tactical fighter, what would be its equivalent radar signature… as big as what—a Piper Cub, a T-38 trainer… what?”
Denys shook his head vigorously. “Ben, understand, we are talking about a major, major, big-time revolution here. We are talking infinitesimal.”
“Well,” I persisted, “what does that mean? On a radar screen it would appear as a… what? As big as a condor, an eagle, an owl, a what?”
“Ben,” he replied with a loud guffaw, “try as big as an eagle’s eyeball.”
2
ENGINES BY GE, BODY BY HOUDINI
KELLY JOHNSON was not impressed. He took one look at Dick Scherrer’s sketch of the Hopeless Diamond and charged into my office. Unfortunately, he caught me leaning over a work table studying a blueprint, and I never heard him coming. Kelly kicked me in the butt—hard too. Then he crumpled up the stealth proposal and threw it at my feet. “Ben Rich, you dumb shit,” he stormed, “have you lost your goddam mind? This crap will never get off the ground.”
Frankly, I had the feeling that there were a lot of old-timers around the Skunk Works who wanted badly to do what Kelly had just done. Instead they did it verbally and behind my back. These were some of our most senior aerodynamicists, thermodynamicists, propulsion specialists, stress and structures and weight engineers, who had been building airplanes from the time I was in college. They had at least twenty airplanes under their belts and were walking aviation encyclopedias and living parts catalogs. Over the years they had solved every conceivable problem in their specialty areas and damned well knew what worked and what didn’t. They were crusty and stiff-necked at times, but they were all dedicated, can-do guys who worked fourteen-hour days seven days a week for months on end to make a deadline. Self-assurance came from experiencing many more victories than defeats. At the Skunk Works we designed practical, used off-the-shelf parts whenever possible, and did things right the first time. My wing man, for example, had designed twenty-seven wings on previous Skunk Works’ airplanes before tackling the Hopeless Diamond. All of us had been trained by Kelly Johnson and believed fanatically in his insistence that an airplane that looked beautiful would fly the same way. No one would dare to claim that the Hopeless Diamond would be a beautiful airplane. As a flying machine it looked alien.
Dave Robertson, one of Kelly’s original recruits and aerospace’s most intuitively smart hydraulic specialist, ridiculed our design by calling it “a flying engagement ring.” Dave seldom minced words; he kept a fourteen-inch blowgun he had fashioned out of a jet’s tailpipe on his desk and would fire clay pellets at the necks of any other designers in the big drafting room who got on his nerves. Robertson hated having anyone look over his shoulder at his drawing and reacted by grabbing a culprit’s tie and cutting it off with scissors. Another opponent was Ed Martin, who thought that anyone who hadn’t been building airplanes since the propeller-driven days wasn’t worth talking to, much less listening to. He called the Hopeless Diamond “Rich’s Folly.” Some said that Ed’s bark was worse than his bite, but those were guys who didn’t know him.
Most of our veterans used slide rules that were older than Denys Overholser, and they wondered why in hell this young whippersnapper was suddenly perched on a throne as my guru, seemingly calling the shots on the first major project under my new and untested administration. I tried to explain that stealth technology was in an embryonic state and barely understood until Denys unearthed the Ufimtsev theory for us; they remained unconvinced even when I reminded them that until Denys had come along with his revelation, we had known only two possibilities to reduce an airplane’s radar detection. One way was to coat the fuselage, tail, and wing surfaces with special composite materials that would absorb incoming electromagnetic energy from radar waves instead of bouncing it back to the sender. The other method was to construct an airplane out of transparent materials so that the radar signals would pass through it. We tried an experimental transparent airplane back in the early 1960s and to our dismay discovered that the engine loomed ten times bigger on radar than the airplane because there was no way to hide it.
So all of us, myself especially, had to trust that Denys Overholser, with his boyish grin and quiet self-confidence, really knew what in hell he was talking about and could produce big-time results. Dick Cantrell, head of our aerodynamics group, suggested burning Denys at the stake as a heretic and then going on to conventional projects. Cantrell, normally as soft-spoken and calm as Gregory Peck, whom he vaguely resembled, nevertheless had the temperament of a fiery Savonarola when, as in this instance, basics of fundamental aerodynamics were tossed aside in deference to a new technology understood only by witches and mathematical gnomes. But after a couple of hours of listening to Overholser’s explanations of stealth, Dick dropped his lanky frame onto the chair across from my desk and heaved a big sigh. “Okay, Ben,” he muttered, “I surrender. If that flat plate concept is really as revolutionary as that kid claims in terms of radar cross section, I don’t care what in hell it looks like, I’ll get that ugly son-of-a-bitch to fly.”
We could get the Statue of Liberty to do barrel rolls with
the onboard computers that achieved aerodynamic capability by executing thousands of tiny electrohydraulic adjustments every second to an airplane’s control surfaces. This computerized enhanced flight stability gave us latitude in designing small, stealthy wings and short tails and mini-wing flaps, and left the awesome problems of unstable pitch and yaw to the computers to straighten out. Without those onboard computers, which the pilots called “fly-by-wire,” since electric wiring now replaced conventional mechanical control rods, our diamond would have been hopeless indeed. But even with the powerful onboard computers, getting into the sky, as Kelly’s boot to my butt suggested, would be far from a cakewalk.
We had a very strong and innovative design organization of about a dozen truly brilliant engineers, working at their drawing boards in a big barnlike room on the second floor of our headquarters building, who simply could not be conned or browbeaten into doing anything they knew would not work. One day, Kelly called upstairs for an engineer named Bob Allen. “Bob Allen there?” he asked. Whoever answered the phone replied, “Yeah, he is.” And hung up. Kelly was livid, but deep down he appreciated the feisty independence of his best people. The designers were either structural specialists who planned the airframe or systems designers who detailed the fuel, hydraulics, electrical, avionics, and weapons systems. In many ways they comprised the heart and soul of the Skunk Works and also were the most challenged by the structural demands of the new stealth technology. Thanks to Ufimtsev’s breakthrough formula, they were being told to shape an airplane entirely with flat surfaces and then tilt the individual panels so that radar energy scattered away and not back to the source. The airplane would be so deficient in lift-drag ratio that it would probably need a computer the size of Delaware to get it stable and keep it flying.
