A unique double-winged experimental aircraft built with Pentagon funding was unveiled in this California high desert community Wednesday by acclaimed aircraft designer Burt Rutan at his Scaled Composites plant, a subsidiary of Beech Aircraft.
Rutan, who gained fame as the designer of the Voyager, the civil aircraft that flew around the world in 1986 without refueling, designed and built the transport under a $2.5-million contract from the Defense Advanced Research Projects Agency, a Pentagon office.
The aircraft, named the Advanced Technology Tactical Transport (AT3), is a subscale flying model of a design that the Pentagon envisions could fill a variety of military missions. It could, for example, ferry troops up to 1,200 miles, land on a 1,000-foot unimproved field and return to its starting point without refueling.
The unusual AT3--which has two wings on each side, one behind the other--made a demonstration flight at the Mojave airport Wednesday. Afterward, an affiliation agreement was announced between Beech and Lockheed to jointly explore the market potential for such a new special-purpose aircraft.
Representatives of Lockheed's Georgia division, which produces such transport aircraft as the C-5 and the C-130, said the agreement establishes "an exclusive working relationship" to define the requirements, design and market potential for such a small transport.
Lockheed officials said the agreement carries no financial commitments and no exchanges of technology. "We will talk together; we will do things together; we will go places together; but we will not live together," said Jack Hansford, director of advanced programs at Lockheed's Georgia division.
The AT3 introduces a number of new technologies that enable the small plane to fly long distances and land on unprecedentedly short fields. It is constructed of fiberglass, carbon fibers and polyvinyl chloride foam--lightweight materials that allow a weight of only 12,000 pounds, Rutan said.
The plane has two sets of wings for complex reasons involving low-drag aerodynamics. To achieve very long range, Rutan had to design the wings with a "high-aspect ratio," which means that they have little rear sweep.
The wings are quite thin and, therefore lack the capability to carry fuel, as wings normally do. He solved that problem by carrying the fuel inside the engine nacelles. But to carry the load, two sets of wings were required, he said.
Another of the plane's technical innovations is an unusual flap mechanism in which eight electrically operated flaps do not move into takeoff position until seconds before takeoff. That allows the aircraft to accelerate more rapidly on the ground and reduce takeoff distance, Rutan said.
Lt. Col. Doc Dougherty, an official in the Advanced Research Projects Agency's Aerospace Technology office, said the Pentagon is interested in the capabilities of an aircraft like the AT3 to perform missions that currently require a large number of specialized aircraft. "There are some really innovative technologies on this aircraft," he said.
The flight demonstration attracted a number of Air Force officials Friday, though the service has no role in the program. "Everything Rutan does is very interesting," remarked Brig. Gen. Charles A. May Jr. "Rutan does things that take unconventional principles and put them in the air."
Worked in Secret
Rutan said he built the aircraft with a crew of four engineers and about 10 shop workers at his facility for aerospace composites, materials that use high-strength fibers reinforced with plastic resins.
The AT3 unveiled Wednesday was only 62% of the size of an actual AT3 and is considered only a "proof of concept" aircraft. By building the demonstration plane to subscale dimensions, significant savings were realized on the project, while also allowing all the important flight characteristics to be demonstrated, Rutan said.
He had said little about his new aircraft until Wednesday, characteristic of his style of working secretly at his small and unpretentious hangar at the Mojave airport.
"It is more convenient for us not to discuss it," Rutan said. "The more time you spend talking, the less you get done. We don't have a public relations department."
Operations at Rutan's Scaled Composites, which was acquired by Beech in 1985, reflect many of the innovative and unconstrained characteristics of the aerospace industry years ago.
"There was absolutely no wind tunnel documentation on this aircraft before the first flight," Rutan said. "We consider this our wind tunnel model."
He said the AT3 was built for only $2.5 million by not having extensive custom tooling and by holding down engineering expenses before production. In addition, his contract provided for payment only as he accomplished specific milestones in the production of the plane, an irregular way for the Pentagon to do business.
"It was an unusual way of doing things, but it is the right way of doing them and it is the way Scaled Composites does business," Rutan said.
Rutan said the AT3 will be test flown about 40 to 50 times during the next several months to explore its full capabilities and determine its flying characteristics. Meanwhile, Lockheed and Beech said they will evaluate the AT3 flight test program to see if they can develop a derivative plane to fill the existing void in small transport aircraft.