Supersonic flight inches closer to reality

Supersonic flight, a longtime dream for makers and owners of private planes, is inching closer to reality.

Nine years after the last trip of the Concorde jetliner, the quest for speed without window-rattling sonic booms is spurring research by billionaire Robert Bass, General Dynamics's Gulfstream, Boeing, Lockheed Martin, NASA and others.

The efforts signal that the time may finally be nearing for corporate aircraft flying faster than sound, about 750 miles (1,207 kilometers) per hour at sea level. Technological leaps since the Concorde's development in the 1960s are converging with the willingness of globe-trotting chief executive officers to pay more for ever-bigger and longer-range jets.

"Most all of the manufacturers have done size, have done luxury and opulence," said Andrew Hoy, a managing director at broker ExecuJet Aviation Group in Zurich. "Time is the biggest opportunity for them all and the only differentiator left."

High operating costs and scant demand for the Concorde's premium fares forced its retirement in 2003 after 27 years in service. The 100-seat jets streaked from New York to London at twice the speed of sound, slicing travel times in half to about three hours.

Planemakers took away a lesson in supersonic economics: It may be easier to find CEOs and wealthy individuals who crave faster corporate aircraft than to persuade airlines to invest in a Concorde successor.

"Given the amount of fuel you need to burn to achieve supersonic speeds, it's going to be a more expensive proposition that only a sliver of the market is going to pay the price for," said George Hamlin, president of Hamlin Transportation Consulting in Fairfax, Va. "When you're talking about a supersonic business jet, that begins to make more sense."

The largest corporate planes already cost almost as much as the smallest Boeing and Airbus SAS airliners, and can fly about 90 percent as fast as sound. Gulfstream's G650 lists for $58.5 million. Bombardier's Global 7000 and 8000 jets retail for as much as $65 million. Warren Buffett's NetJets unit ordered 20 last year.

The chief obstacle to supersonic flight is the same one that bedeviled the Concorde: the sonic boom. The U.S. Federal Aviation Administration outlawed such flights by civilians over land in 1973 because of the noise, and other countries followed.

Reversing that ban will be pivotal to any revival of supersonic travel, because the planes would lose their business case if they can't fly at top speed, according to Savannah, Georgia-based Gulfstream.

"That requires a solution to the sonic boom problem, and that's where our research efforts are focused," Preston Henne, Gulfstream's senior vice president of engineering and test, said during an aviation conference in Orlando, Florida, on Oct. 29. "We continue to make progress on that."

NASA expects to start building a demonstrator plane in 2016 to show that disruptive booms can be minimized, and that jet may fly after 2020, according to Peter Coen, chief of supersonic research. In an industry in which Boeing's Dreamliner took more than a decade to go from the Sonic Cruiser concept to first delivery, that's not a long-range timeline.

"This is a high-value niche market; the winner here will be the first to market," said Brian Foley, an aviation consultant based in Sparta, N.J. "That's why there's interest and that's why there's motivation for these people to keep on trying."

Success for a new generation of planes is hardly assured, said Foley, who spent 20 years as marketing director at Dassault Aviation SA's Falcon business-jet unit.

No follow-on aircraft has emerged since Air France and British Airways parked their Concordes, which were grounded for more than a year after the 2000 crash in Paris that killed 113 people when one of the Air France jets struck runway debris.

The planes slurped twice as much fuel as a Boeing 747 jumbo jet with only about a quarter of the passengers, and round-trip tickets in 2003 fetched as much as $13,500, then the sticker price on a Dodge Neon compact.

While new designs and engines may tame the roar billowing from a supersonic jet in flight, engineers still must muffle the so-called focused boom, the sharp crack that occurs as a plane first goes past the sound barrier. Emissions and maintenance on high-performance engines also remain challenges.

"It doesn't matter which manufacturer is working on it at the time, when you ask them when it's going to be a reality, they generally all say, 'Within 12 years,'" Foley said. "That seems to be the magic number. It doesn't matter if someone asks them in 1980, 1990 or 2000, there will be one within 12 years."

Supersonic-flight boosters such as NASA's Coen see reason for optimism. Planemakers can employ more-powerful engines, use new materials such as the lightweight composites on Boeing's Dreamliner and draw on years of aeronautical knowledge from the Concorde's operations and from making supersonic warplanes.

Gulfstream is experimenting with a telescoping rod protruding from a jet's nose to disrupt the sound waves that cause sonic booms. Bass, a co-founder of investment firm Oak Hill Capital Partners, has hired a NASA research jet to test a high-speed wing design from his Aerion Corp.

Boeing and Lockheed have devised supersonic concepts with slender fuselages and rear-mounted engines to damp drag that contributes to the noise. NASA is testing models as long as 3 feet (0.9 meter) in wind tunnels and studying nozzles from General Electric Co. and Rolls-Royce Holdings Plc for future engines, Coen said.

"We were able to achieve both good aerodynamic elements and low sonic boom simultaneously," Coen said. "We think we're there or pretty close. That was a really exciting development over the past year."

After holding public meetings on supersonic flight from 2008 through 2011, the FAA is shifting to gather data from NASA and industry groups as it weighs noise regulations.

"Current research has demonstrated enough progress on reducing impact of sonic booms before they reach the ground for us to revisit this issue," the FAA said in an e-mailed response to questions. No new public sessions are scheduled.

Bass's Aerion doesn't want to wait for any regulatory changes. The Reno, Nev.-based company has a low-drag wing design that it says will allow a jet to fly efficiently at subsonic speed over land and at as much as Mach 1.6, or 1.6 times the speed of sound, over the ocean.

Aerion was in "deep discussions" on a planemaker partner to build the craft as the recession began in late 2007, Chief Operating Officer Douglas Nichols said. Before the economy tanked, Aerion had 50 commitments for an $80 million supersonic plane, Nichols said. Bass declined to comment on Aerion through a spokeswoman, Marcia Horowitz.

"We have a thoroughly committed and patient investor who believes these things and is heavily involved in the business," Nichols said. "The next frontier is speed and the industry will get there sooner or later. Our wish is sooner."