April 9, 2012

What NASA called a “breakthrough” in wind tunnel testing could soon take the “boom” out of supersonic flying, and scientists at the Dryden Flight Research Center believe it could benefit business aviation in “years rather than decades.”
Face it: The biggest reason that business aviation hasn’t gone supersonic yet is the sonic boom. Even when supersonic aircraft fly at high altitudes, that big “ka-BOOM” has proven so unacceptable that supersonic flight has been banned over populated areas for decades.

However, NASA has hailed recent wind tunnel tests of supersonic models designed by both Boeing and Lockheed as breakthroughs.

“It’s the first time we have taken a design representative of a small supersonic airliner and shown we can change the configuration in a way that is compatible with high efficiency and have a sonic signature that is not a boom,” said Peter Coen, NASA’s Supersonic Fixed-Wing project manager, quoted by Aviation Week magazine.

Before now, the characteristics of low drag at supersonic cruise speeds and a low-level boom have been considered mutually exclusive. The breakthrough hailed by Coen came in the discovery that they are, in fact, not.

“The game-changing technology out there is having tools available to design the external shape of the vehicle to give you a low sonic boom on the ground,” said Tom Jones, project manager for SCAMP, NASA’s Superboom Caustic Analysis and Measurement Program. His job, along with investigator Ed Haering, is to create super loud sonic booms in order to study how to create those that are so quiet they would make overland supersonic flight acceptable to the general public.

The tools in question are fast computers and modeling capabilities that weren’t possible before 2003, Haering said.

Because weight is a factor in the loudness of a sonic boom, all three scientists agree that the first supersonic aircraft quiet enough to fly over land may well be a business aircraft.

“It’s definitely easier with business-sized jets than with jumbo jets,” Haering said.

Already, Lockheed Martin has designed a Quiet Supersonic Transport (QSST) it says would cost about $80 million and fly between Mach 1.6 and 1.8. Gulfstream, which had been working with Russian researchers, said it continues its quest for an overland supersonic business jet. For that matter, Russia’s TsAIG research consortium touts its continuing research in the field.

But with the wind tunnel breakthrough recently touted by NASA, researcher Tom Jones is optimistic.

“The first step will be an X-plane,” he said. “It is my hope and my goal to make sure that we develop an X-plane demonstrator in years, not decades.”