Enlarge By Paul Weatherman, Lockheed Martin  The interior of the original Dornier 328J mid/aft fuselage is comprised of approximately 3,000 parts which will be replaced with a larger structure comprised of 230 composites parts.

Lockheed Martin is building the first military cargo jet in which the craft's structure will be made of fibers, resins and epoxy, replacing metals such as aluminum and titanium that have been in use in aircraft for decades.

The composites hold huge potential for saving weight, a critical factor in aviation performance and fuel consumption, aviation experts say. The goal is to put the test plane in the air by October, one year after the $50 million contract was awarded — and just 18 months after the concept took shape, a record time for the military.

"This is fundamentally a different way of building aircraft," says Mike Swanson, project lead engineer. "We're going up against 70 years of traditional metal fabrication."

Non-metal parts have been used in commercial and military aircrafts for more than a decade. But the Air Force says the new Advanced Composite Cargo Aircraft will be the first military transport to incorporate the latest fiber technologies and production methods in the airframe itself.

Ken Miller, assistant secretary of the Air Force for acquisitions, said expected savings of 20% to 30% in weight will translate to similar savings in fuel. While that can reduce costs, a bigger payoff for the military is being able to fly heavier payloads for longer distances.

The Air Force spent $4.2 billion on petroleum in 2005, up more than one-quarter over the previous year and more than the Army, Navy and Marines combined, according to the Air Force.

There are other benefits besides potential significant fuel savings, Swanson said during an interview at the Lockheed Martin facilities where the plane is being built:

• Improved performance and durability: Fiber materials resist corrosion and eliminate metal fatigue, factors that force major rebuilding of military aircraft after 20 to 30 years of hard use.

• Fewer parts: The number of parts will be reduced by at least 90% if, as planned, 306 composite parts replace up to 4,000 metal ones. The Air Force can't say if building planes with composites will be cheaper than metal. But lowering costs of producing composites through new manufacturing methods is a goal, Miller says.

Speeding up the lengthy process of getting a plan from concept to reality may also help with costs.

"We're trying to do this very, very quickly," Miller says. "It normally takes us forever to build new airplanes."

Currently the military relies on the aging transport workhorses, C-5 Galaxy, which dates to the late 1960s, and C-130 Hercules, which first flew in 1954.

The experimental plane is smaller and won't replace either. But it will fulfill a burgeoning need for a lighter more nimble transport plane that can deliver ground combat vehicles close to the battlefield on short or unprepared landing strips, says Graham Warwick, U.S. editor of Flight International magazine.

Warwick says the Air Force project comes at the same time that the Army is proposing a tilt-wing vertical-take-off airplane. Only one will win out.

The prototype project is underway in a giant hangar here that is off-limits to the public. It is the home of Lockheed Martin's Advanced Development Programs — also known in aviation lore as the "Skunk Works." That name, now trademarked, emerged during World War II when the company set to work in secret developing a U.S. military fighter jet that could match Germany's fighters.

Later moved to the high desert test range here from its original location in Burbank, the Skunk Works has given birth to several revolutionary and legendary aircraft — high-flying supersonic spy planes such as the U-2 and SR-71 Blackbird, and advanced stealth fighters such as the F-115 Night Hawk and F-22 Raptor.

To show how a prototype can be put in the air much faster than past practice, Lockheed Martin is using an existing airplane, a German-built Dornier 328J regional jet, and modifying it. Workers literally sawed off the cockpit and discarded much of the rest of the plane and will replace it with a bigger, lighter composite airframe.

Two main pieces of the fuselage, top and bottom, an interior floor and reinforcing parts will all be made of composite materials. The two halves were shaped with giant custom-made foam tools, or molds, and rest in metal frames while engineers use lasers and computer-guided cutting machines to precisely fit parts and sculpt the final shape. When ready workers will glue the halves together and bond the new fuselage to the original metal cockpit.

The numerous nuts, bolts and metal fasteners that hold current military planes together will largely not be needed.

If successful the plane will represents "potentially game-changing technology" that could represent the future of military aviation, Swanson said.

"There's a high payoff for the Air Force if this works," he said.

Enlarge By Paul Weatherman, Lockheed Martin Santiago Ramos and Gloria Espinoza work on a section of honeycomb core composite material to be integrated into the Advanced Composite Cargo Aircraft composite structure.

		The cockpit section of the Dornier 328J will be integrated with new composite mid/aft fuselage for the U.S. Air Force. Non-metal parts have been used in commercial and military aircrafts for more than a decade, but this will be the first to incorporate the technology into the airframe itself. By Paul Weatherman, Lockheed Martin