B-2 Origins and Development

* Formal work on the development of "low-observable" or "stealth' aircraft in the US began in late 1974, when the Defense Advanced Research Projects Agency (DARPA), a Pentagon organization that works on "blue sky" advanced technologies, began "Project Harvey", an effort to build a stealthy aircraft. The project was named after a famous comedy about a giant invisible rabbit named, of course, Harvey.

Project Harvey was not actually the first time the US had incorporated stealth features into aircraft. In the early 1960s, Firebee target drones had been modified for the reconnaissance role as "Lightning Bugs" or "Fireflies". They had been enhanced with stealth features, including pads of radar-absorbing material (RAM) on the sides of the fuselage; and a wire mesh over the air intake to mask the blades of the engine compressor, which tends to sparkle or "glint" on radar as it spins, like a spinning disco ball in a lights show. The high-flying Lockheed SR-71 Blackbird reconnaissance aircraft was designed to be stealthy as well, though it also used high altitude and speed for protection.

The goals of Project Harvey were much more ambitious: to create an aircraft that could survive on stealth alone. DARPA awarded study contracts to McDonnell Douglas and Northrop in January 1975. Lockheed officials found out about Harvey through the grapevine and insisted on participating, paying for their design effort out of company funds. That was a gamble, but it paid off: Northrop and Lockheed were selected by DARPA to design a stealth demonstrator, the "Experimental Survivable Testbed (XST)", while McDonnell Douglas was eliminated from the competition. The XST program's goals did not include building a flight demonstrator; Northrop and Lockheed were to build large-scale mockups, which would then be mounted on a pole at Holloman AFB in New Mexico and subjected to tests to determine their "radar cross section (RCS)".

Work on the Northrop demonstrator was conducted by a team under John Cashen, a pushy sort who had come to Northrop after working at Hughes on how targets appeared to radar and infrared sensors, and Irv Waaland, a designer who had come over to Northrop from Grumman. Although the Lockheed team used a computer program to come up with their design for the XST, Cashen said later that Northrop didn't have such a luxury, and worked up their design using a combination of theoretical analysis and cut-and-try experiments.

The Lockheed team won the XST competition in March 1976, and went on to build two "Have Blue" stealth demonstrator aircraft, which paved the way to the larger Lockheed F-117 stealth fighter. Northrop lost because one the team's initial design assumptions was that a stealthy aircraft should be hardest to pick up from the front and below, but the DARPA requirement, rightly or wrongly, insisted on measuring stealthiness from four quadrants. The Lockheed design proved better able to meet the all-round stealth requirement. Lockheed also had an advantage in possessing a good knowledge of RAM technology, which that company had developed for the SR-71.

However, in December 1976 DARPA officials called up Northrop to discuss a stealth aircraft as part of the Pentagon's "Assault Breaker" effort. Assault Breaker was a wide-ranging program that envisioned use of new "smart" munitions, deep-penetrating strike platforms, and advanced sensors to smash numerically-superior Soviet armor forces in the case of a European war. DARPA wanted Northrop to study a stealthy "Battlefield Surveillance Aircraft -- Experimental (BSAX)" that would spot targets for Assault Breaker weapons. Since BSAX was supposed to loiter around a battlefield instead of performing an attack and leaving, it would present all angles to an enemy and so required all-round stealth. An initial model of BSAX was tested in the summer of 1977, with results that Waaland later described as "disastrous". One of the design team members, Fred Oshira, did some rethinking of the design and came up with a solution, a new airframe design that gave very little for a radar beam to grab on to. In April 1978, DARPA awarded Northrop a contract for a single flying prototype of the design, which was given the codename "Tacit Blue".

Tacit Blue performed its initial flight in February 1982, followed by 134 more flights over a three-year evaluation. It was unarguably one of the ugliest aircraft ever built, and was unflatteringly known as the "Whale". It featured a fuselage resembling a stretched upside-down bathtub with a wedge-shaped flat panel under the nose; an engine intake buried in the back; wedge-shaped wings; and a vee tail shielding the exhaust. Tacit Blue was powered by twin high-bypass turbofan engines, had a wingspan of 14.7 meters (48 feet 2 inches), a length of 17 meters (55 feet 10 inches), and a weight of 13,605 kilograms (30,000 pounds).

In 1984, the Army and Air Force decided to collaborate on a non-stealthy battlefield surveillance platform, which would emerge as the E-8 Joint Stars, based on the Boeing 707 airliner. Tacit Blue was put in storage in 1985. It was finally announced to the public in 1996, and is now in the possession of the USAF Museum at Wright Patterson Air Force Base in Ohio.

* While Northrop was beginning work on Tactic Blue, back at the Pentagon the top brass were becoming very interested in stealth. In 1977, William "Bill" Perry, Secretary of Defense for the Carter Administration, formed a group to perform studies on the military potential of stealth. The group's conclusion was that improvements in adversary air defenses were threatening to make the current "non-stealthy" US bomber force obsolete. In addition, stealth would allow a single aircraft to make a precision attack on a target, instead of requiring a full "strike package" of multiple bombers, with fighter escorts, jamming platforms, and defense-suppression ("Wild Weasel") aircraft.

The group recommended that two stealthy strike aircraft should be built, an "A Airplane", a fast-track development of the Lockheed Have Blue demonstrator, which would emerge as the F-117; and a "B Airplane" that would be bigger and more capable but would take more time to roll out.

The B Airplane concept grew over time into a full-blown, long-range heavy bomber. Lockheed had proposals, one apparently being a machine something like a scaled-up F-117 and codenamed "Senior Peg", but the Pentagon also asked Northrop to investigate. Northrop officials were uneasy about working on a heavy bomber, since the company's last effort along such lines, the XB-35 / YB-49 flying wings of three decades earlier, had come close to financially wrecking the company. They did agree, however, and responded with two proposals, one of which, cooked up by designer Hal Markarian, took its inspiration from the YB-49. Incidentally, there is a story, possibly true, that the YB-49 had shown a surprising ability to disappear from radar at certain viewing angles.

The proposals were duly submitted in August 1979, and Bill Perry came back with a study contract, asking Northrop to refine the flying wing concept. Waaland joined up with Markarian, and the team also acquired aerodynamicist Hans Grellman, as well as Dick Scherrer, a designer who had recently come over from Lockheed. At the outset, the Northrop "Advanced Strategic Penetration Aircraft (ASPA)", as it was known, was seen strictly as an insurance policy, since Lockheed was regarded by the brass as the front-runner.

However, by the time the Air Force issued a request for an "Advanced Technology Bomber" in September 1980, formalizing the ASPA studies into a program to develop an operational aircraft, Northrop's design was looking much more attractive, and company officials felt they had a shot at winning the contract. Lockheed was partnering with Raytheon on their ATB proposal, and so Northrop approached Boeing to sign up as a partner. Northrop's chairman, Tom Jones, had a meeting with his counterpart at Boeing, Thornton Wilson. Wilson, to his embarrassment, was almost completely ignorant of the ATB program, but Jones filled him in, and Wilson agreed to join immediately. Witnesses claim that Wilson then turned to one of his people and said: "Don't ever let me be caught in this position again!"

The Northrop concept, codenamed "Senior Ice", was judged superior to the Lockheed "Senior Peg" proposal, and Northrop won the ATB contract in October 1981. The contract covered delivery of two static-test airframes, one flying prototype, and five evaluation machines. While the Carter Administration had pushed stealth, there had been some ambivalence about production, but the new, hawkish Reagan Administration wanted to go full speed ahead on the ATB. The initial plan envisioned production of 127 ATBs, in addition to the five evaluation machines, which would be brought up to operational specification.

The Pentagon wanted to keep the contract a secret, but Tom Jones pointed out that Northrop had to publicly declare large company contracts in order to be in compliance with securities laws. The government, caught by their own regulations, issued the shortest and least informative statement possible about the contract. It would be the last public mention of the program until 1988.

* There was much more work to be done to get such a complicated machine into the air, all the more so because the ATB requirements had expanded over time. Aircraft size and munitions load had grown, and although the ATB was originally seen as a high-altitude penetration machine, the Air Force decided that a low altitude capability would be nice as well -- there was no saying that the Soviets might eventually develop more powerful and smarter radars that could pick up a high-flying stealthy aircraft.

In any case, the work went forward, and the first "B-2" prototype, "Air Vehicle One (AV-1)", was rolled out at the Northrop plant in Palmdale, California, on 22 November 1988. The rollout was public, but observers were restricted to stands that kept them well away from the aircraft and limited their view of it to the front. Although the F-117 had been kept secret for years after its first flight, its test flights had been restricted to night, and that wasn't regarded as acceptable for the B-2. Since it would have been quickly spotted during daylight flights there was no sense it keeping it a complete secret, and nobody tried.

However, the security restrictions at the rollout weren't completely "airtight", in a highly literal sense of the word. Michael A. Dornheim, a reporter from AVIATION WEEK magazine, flew a light aircraft over the B-2 and had a photographer take pictures, obtaining one of the magazine's biggest scoops of all time and justifying its nickname of AVIATION LEAK. It was all perfectly legal.

The damage, if any, had been done, and the program went forward. AV-1 performed its first flight on 17 July 1989, flying from Palmdale to Edwards AFB in California. Northrop Test pilot Bruce Hinds and USAF Colonel Richard Couch were at the controls. AV-2, the first of the five evaluation machines, performed its initial flight on 19 October 1990. The first production B-2A was accepted by the US Air Force Air Combat Command (USAF ACC) at Whiteman AFB in Missouri on 17 December 1993. Due to the merger of Northrop and Grumman in the 1990s, the aircraft is now the "Northrop Grumman B-2".

Source: http://www.vectorsite.net/avb2.html