The firm is currently in the second stage of a three-part research feasibility study. The first phase, HSR 1, was started in 1989 to investigate the engines and emissions, and was headed by Pratt & Whitney and GE.

"Boeing is currently heading a U.S. industrial team that has 440 million dollars from High Speed Research (HSR) II to investigate the feasibility of an airframe and structure for the HSCT program," Harrison adds.

"The goal of HSR is to investigate enabling technologies to answer eventually the ability to decide whether to proceed with the design of HSCT," Harrison says. "It must be environmentally benign and economically viable. Currently, the technological barriers are very significant."

Boeing's projected aircraft would have a baseline design carrying more than 300 passengers, as well as a range of 5800 statute miles, flying at Mach 2.4 [1775 mph] at 60,000 feet [18 kilometers] with four engines each with 50,000 pounds of thrust, according to Harrison. The Concorde currently carries 100 passengers, and has a range of 4000 statute miles flying at Mach 2.

"We currently have no cost projections for the project, but we know that a HSCT will not fly before 2005 and we are shooting for a price in agreement with subsonic aircraft of the day," Harrison says. The most expensive subsonic aircraft flying today, Boeing's 747, costs around 150 million dollars, he said.

"Our requirements for feasibility are that we have to be able to build the aircraft, which will require a great deal of new composite materials that are very different from metal alloys, [and] the price must be such that the customer can afford it," Harrison says. "[A further requirement is that] we can afford to build it so passengers in three classes can afford to pay a slight surcharge, 10 to 15 percent, above the existing subsonic fare of the day for a flight taking 50 percent of the time."

Flyers willing to pay the higher price, Harrison says, would recoup their investment in time saved. He offers the example of a flight from Los Angeles to Tokyo that takes 10.3 hours today, but would take only 4.3 hours in an HSCT.

But Harrison cites problems that foreseeable technology will not be able to overcome. "The aircraft will not be able to fly over populated land masses," Harrison says, "and it must be able to operate subsonic at takeoff, too [because of noise regulations]."

If the proposed airplane design meets environmental regulations, however, that will be an innovation in itself. Currently, the Concorde fails to meet the landing requirements at some US airports, restricting its flying routes. In the future, Harrison claims, supersonic aircraft will be able to comply with all environmental laws.

"The noise and pollution [emissions] will meet the regulations of the day," he says.

If Boeing decides to produce supersonic aircraft, it will be on a large scale.

"The minimum production would have to be 500 aircraft," Harrison says. "We do not believe there is a market for two airplanes."

But even Boeing's resources may not be enough to develop a project of HSCT's size. "We do not believe it will be possible for any one company to do this alone," Harrison says.

"We do not foresee federal support and we do not seek it," Harrison adds. "NASA's role has traditionally focused on technological development, and that goes back to the National Advisory Committee for Aeronautics of the 1930s."

Goldin says that embracing new supersonic technology could bring America's market share in aviation to nearly 80 percent, and would create jobs similar to those that are currently being lost through defense cutbacks.

According to NASA literature, the program will be the cornerstone of NASA aeronautics for the 1990s.

Experimentation