The high desert country northeast of Los Angeles has quite an aviation history. Among the incredible flying machines that saw their birth and first flight here: the U-2 spy plane, the SR 71 Blackbird supersonic high-altitude reconnaissance aircraft, the B-2 bomber and the F-117 Nighthawk stealth fighter, which lit up the skies over Kosovo.

Now a new chapter in military aviation is being written in Palmdale, but one with less lofty, more terrestrial aims. Here, aerospace giants Boeing Co. and Lockheed Martin Corp. are locked in a dogfight to develop and produce the Joint Strike Fighter, a multiservice plane designed for the first time with low cost rather than gee-whiz technology as its primary goal.

The stakes in this battle are enormous for both the industry and the Pentagon. At $200 billion and counting, the more than 3,000 fighters the winner will make for the Air Force, the Navy and the Marines as well as a few select allies represent the largest weapons purchase currently underway in the world. But the JSF is also a test of whether the aerospace industry and the military can design and build products under the same strict cost and time pressures faced in the commercial world.

"This is a prize," said Jay Behuncik, a defense specialist at the Washington Analysis Group. "This is the first great military program of the 21st century."

Among the challenges is to develop three different versions of the plane to meet the varying needs of the three military services, while keeping the basic design of the plane as uniform as possible to hold down costs. If successful, this would be the first joint fighter development; a similar effort in the 1970s failed.

Already, there are some inklings of trouble with the JSF. Boeing found its radically shaped wing design too heavy for landing on a Navy carrier deck, while Lockheed ran ahead of projected costs developing an unconventional engine nozzle to provide downward thrust for the Marines' version, which has to be capable of a vertical takeoff. The Pentagon agreed to cut back on some of the planned flight testing and rely more on simulation to keep the program within budget.

"There was a cost management problem such that it begged . . . a rework," said Maj. General Michael Hough, the Marine who heads the JSF program for the Pentagon. "We can't afford any more burps like that."

Keeping the JSF within cost and on track is paramount, given the vote in the House last week to cut $1.8 billion in funding for the Air Force's F-22 fighter, made by Lockheed. Lawmakers remain concerned the Pentagon cannot afford all three of its newest fighter programs -- the JSF; the stealthy, advanced F-22; and the Navy's Boeing-made F-18 E/F.

While the JSF is the furthest away from production -- the first one won't enter service until 2008 -- it is also the plane with the least developed political constituency, since it does not yet involve the thousands of jobs that come with full-scale manufacturing. Building all three in the quantities envisioned by the Pentagon would cost taxpayers $340 billion over the next 27 years, according to congressional budget experts.

"Clearly, going ahead with all three tactical fighters is enormously expensive," said Steve Kosiak, an analyst with the nonpartisan Center for Strategic and Budgetary Alternatives. "It's hard to see the money being there."

That's why some see the JSF's future complicated by the House's vote to cut money for purchasing six F-22s. If the Senate is unable to restore the money and the F-22 is somehow cut back, or canceled, it could mean the military would want a more capable JSF. But that would likely raise its cost, threatening its support within the Navy, which is already buying the more expensive F-18. Conversely, if the F-22 is saved, the money to do so may come from the JSF, forcing a delay in the program.

"This creates a very confused picture for the JSF," said Loren Thompson, chief operating officer at the Lexington Institute, an Arlington think tank. "If the F-22 were to die, this would greatly increase the need for the JSF. But the first thing that would go out the window is the low-cost aspect of the program."

The JSF already faces some tall demands. The Air Force wants a cheap replacement for its workhorse F-16, a plane that can take off and land conventionally from airstrips. The Navy wants a stealthy accompaniment to the F-18, a plane that must be able able to land on a carrier. The Marines want a "jump jet" that uses engine thrust to take off and hover vertically. The British, who are financial partners in the program, also have similar demands. But the Pentagon wants all three versions to cost between $28 million and $36 million a copy, not much more than the 1970s-era fighters they will replace.

"There were compromises," acknowledged Harry Blot, Lockheed's deputy program manager. "Could I have built a faster, higher-G aircraft? Yes, but not for the price."

Both companies are acutely aware of the importance of winning the JSF contest in 2001, when the Pentagon is to pick the sole manufacturer. After McDonnell-Douglas Corp. lost out in an earlier round, the company was essentially finished as a builder of fighter aircraft and a year later was swallowed whole by Boeing in a $15 billion merger.

For Boeing, the world's largest maker of commercial planes, the JSF would be its first production fighter built on its own since the Second World War, though its design team includes former McDonnell engineers. For Lockheed, the JSF represents the natural heir to its F-16, the most popular fighter in history.

"It'll be very competitive," said Frank Statkus, Boeing's program manager. "It's absolutely imperative we win some or all of this work."

Implicit in Statkus's comment is the belief among many close to the JSF that the government will not simply choose one victor, despite statements to the contrary. The program may be too big, and the arms industry now too small following years of lean defense budgets, to allow one company to dominate the military's future fighter budget.

There are precedents for some kind of shared production: Boeing is already a major subcontractor to Lockheed on the F-22 and the two companies are splitting an Air Force contract to build an expendable space rocket.

But such talk is quickly countered by the Pentagon, which prefers the idea of maintaining vigorous competition among its prime contractors.

"My charter and my rudder and my orders are, Mike, proceed full bore" to the selection of a winning contractor, Hough said. "I want to keep them both competitive."

In the meantime, both companies are proceeding at their supersecret research labs here -- Lockheed's famed Skunk Works and Boeing's Phantom Works -- on state-of-the-art demonstrators that will show how the plane will perform in flight. Boeing is relying heavily on lessons it learned building the 777 jetliner, including using live videoconferencing to cut down on travel between Seattle and Palmdale. The front fuselage of its first prototype was assembled in St. Louis, then shipped to Palmdale, where it was attached to the rest of the fuselage in snap and fit style. Rather than use traditional and expensive specialty tooling, Boeing is relying on lasers to guide workers in placing parts together. The company says such techniques have reduced by half the number of workers needed to produce its prototypes.

Lockheed, meanwhile, has embraced a variety of lean manufacturing techniques, such as using just-in-time inventory and borrowing parts off other aircraft to reduce its costs and the time taken to make its demonstration aircraft.

All of this is an about-face for a community of engineers who have often operated as if the pursuit of technology itself was the only thing that mattered -- and damn the cost.

The contractors are using modern technology to cut costs. One example is paint, which in the past has been very expensive to apply and fraught with environmental concerns. On the JSF, though, Hough said the companies are testing a new kind of environmentally friendly wrap that workers can apply quickly with a hair dryer. Hough says the idea is so unique he doesn't even know how to measure the cost savings.

There are other such techniques. Borrowing from the commercial world, the plane is being designed with modular, open computer architecture. Instead of replacing the entire avionics systems when new technologies arrive, the military will just replace circuit boards or individual chips.

"The design approach is, number one, affordable," said Lockheed's Blot. "Fortunately, technology is on our side now. We're putting technology in to get the cost out."

When the demonstrator planes begin their first flights next spring at Edwards Air Force Base, the hope in the industry is that enough cost-savings will have been gained to prove the point that a 21st century fighter can be designed and built for 20th century prices. If the JSF succeeds at that mission, where others have failed notably in the past, then it might well earn its own place in aviation history.

Nose to Nose

Lockheed Martin and Boeing are in intense competition to win the contract for the next generation of strike aircraft for all three branches of the military. Affordability, says the military, is a key aim of the Joint Strike Fighter program. Here are some preferred features:

Single-seat cockpit

F-119 derivative engine

Continuous wing/body structure

Ability to hover and to handle short takeoffs, vertical landings.

Aircraft the JSF should complement . . .

Navy: F/A-18E/F

Air Force: F-22

. . . and aircraft it should replace:

Air Force: F-16 and A-10

Marine Corps: AV-8B and F/A-18

U.K. Royal Navy and Royal Air Force:

Sea Harriers and GR7s

Key dates in development of the Joint Strike Fighter aircraft:

1994: Military begins to explore the concept of a Joint Strike Fighter program.

1996: Competitive contract awards go to Boeing and Lockheed Martin for concept demonstration programs.

1997: Flying demonstrations begin.

Following dates are projected:

Spring 2000: Military selects Boeing or Lockheed as its contractor.

2000: First flight is scheduled.

2007: First operational aircraft scheduled to be delivered.

Boeing

Team members include:

Raytheon Systems

Rolls-Royce

Lockheed Martin

Team members include:

Northrop Grumman

British Aerospace

SOURCES: Joint Strike Fighter program, Boeing, Lockheed