Aerospace: Supersonic Boom

By JEROME CRAMER/PARIS

Even after 22 years in service, the Concorde still seems like a vehicle from the future. It can fly from New York City to London in just three hours, for which passengers pay an astronomical $4,167 each way. Yet for all its speed and prestige, the Concorde has always been a money loser for its operators, Air France and British Airways. The SST guzzles too much fuel, carries too small a passenger load and makes so much noise that 30 countries have restricted its use.

So why are aerospace engineers around the world scrambling to build the next generation of this billion-dollar white elephant? In a word: Asia. The booming market for transpacific flights is expected to help create a lucrative new market for a plane that can shrink long distances. By the end of the decade, transpacific travel is expected to reach 315,000 passengers a day, or 15% more than will cross the Atlantic daily. A plane flying at Mach 2.5 (2 1/2 times the speed of sound, or 1,800 m.p.h.) could more than halve the duration of a Los Angeles-Tokyo flight to just 4 1/2 hours.

The race to build what has been dubbed the High Speed Civil Transport (HSCT) is a multibillion-dollar gamble fraught with technological challenges. To be profitable, the plane will have to carry more than twice as many passengers as the Concorde, operate at higher speeds, span greater distances, use less fuel, run quieter and produce far less pollution. Can do, say the plane's advocates, though any such plane isn't likely to fly until at least the year 2005.

The payoff could be enormous. The nation or group that successfully develops the HSCT is likely to dominate the aircraft market well into the 21st century.

The job is too big for any one company. Aerospace firms are forming joint ventures and seeking government subsidies to foot the research bill. NASA is spending $284 million over five years to develop technologies that U.S. companies can apply to their work on the HSCT. Rival U.S. aircraft builders Boeing and McDonnell Douglas have teamed up to design an airframe, as have British Aerospace and France's Aerospatiale, the same partnership that built the Concorde. American jet-engine builder Pratt & Whitney is working closely with its nemesis, General Electric, to build a power plant that is quieter, more economical and clean burning. France's Snecma and Britain's Rolls-Royce have launched a similar joint project. Gulfstream, which makes business jets, is working with British and Russian designers to build a 19-passenger supersonic business jet. "Our clients will pay almost anything to go faster," says company CEO Allen Paulson.

Like shrewd roulette players, the Japanese are spreading their money around, spending millions on overseas research projects. Since the country lacks the experience to build an HSCT on its own, the Japanese are investing "just enough in both European and American projects so they can jump in with the winner and become partners," says John Swihart, a U.S. aerospace consultant.

British Aerospace has a team of 50 engineers working closely with France's Aerospatiale on a "son of Concorde" that will carry 250 to 300 passengers at Mach 2 as far as 5,500 miles. The Germans, for their part, have an even loftier plan. Deutsche Aerospace has been developing the Saenger project, a hypersonic plane that would fly as fast as Mach 25 by the year 2030. As a first step, the company is experimenting with a version that would fly at Mach 5-6, launch a satellite into orbit and then glide back to earth. "The Germans have spent several hundred millions of dollars developing Saenger, and it could give them a head start with the HSCT," says Jerry Grey, a director of the American Institute of Aeronautics and Astronautics.

American plane builders have been down this runway before -- and got burned. In 1971 Lockheed dropped its plans for an SST. Later that year Boeing too killed its project, after Congress scrapped subsidies because of concern about noise, pollution and cost. The $4 billion Concorde project went ahead, but only 16 planes were built, and aviation experts believe the original investment has never been recouped. Many aerospace executives now believe the supersonic transport's time will finally come, but its success will depend on the scientific ingenuity brought to bear on a host of technical problems.

Probably the biggest concern is environmental. To save fuel, the plane will have to cruise in the thin atmosphere at about 60,000 ft., close to the ozone layer, which protects the earth from ultraviolet rays. But jet engines produce nitrogen-oxide emissions, which at that altitude could potentially destroy more ozone than chlorinated fluorocarbons did before they were banned in 1978. Engineers at Pratt & Whitney and General Electric are working on several concepts to reduce such emissions by heating and burning the fuel in gradual stages. The goal is daunting: to reduce nitrogen-oxide exhaust to as little as 10% of the volume emitted by conventional airliners.

To achieve high speed and long ranges, the HSCT will require an airframe that is proportionately 30% lighter than the Concorde's. The answer lies in modern composites of silicon and carbon, which will be able to withstand aircraft-skin temperatures that reach 600 degreesF or more at Mach 3.

Noise reduction may be the biggest political problem for the plane to overcome. By tinkering with the plane's silhouette, engineers believe they can reduce the impact of its sonic boom, though probably never enough to allow supersonic flight over populated areas. To reduce noise during takeoffs and subsonic travel, designers hope to build a combination engine that can operate in a quiet, turbofan mode on flights from, say, Chicago to Los Angeles but then kick in to a more powerful, turbojet mode for the supersonic trip from California to Japan.

But will the plane be economical? Boeing officials believe the HSCT needs to break even with no more than a 10% to 15% surcharge over regular ticket | prices. "I'm not interested in building a plane that only rich people can fly," says Boeing senior vice president Benjamin Cosgrove. The Concorde's ticket prices, which barely cover its fuel costs, run about four times as high as conventional fares. Aircraft manufacturers predict that the HSCT will be economically feasible to build and operate only if the fleet is large, from 1,000 to 2,000 planes. This means that two or perhaps three competing designs for the HSCT may eventually emerge.

Engineers hope that full-scale production of an HSCT could be under way by the end of the decade, with commercial operation a few years later. One obstacle might be a decision on the part of Boeing and Europe's Airbus to build huge new subsonic aircraft that could carry 600 to 800 passengers. If manufacturers switch their attention to the new subsonic craft, the drain on resources could delay the HSCT until 2015. But as business and tourism grow ever more global, the lure of a high-speed aircraft increases. "I never thought a supersonic civilian aircraft was needed," says Thomas Donahue, general manager for advanced technology at General Electric. "But I just got back from doing business in Australia, which means a 14-hour flight. Believe me, now the prospect of such a plane seems very real."

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With reporting by Edwin M. Reingold/Los Angeles