Shhh...: Gulfstream Researching Sonic Boom Suppression
Can a supersonic bizjet be in our future? If Gulfstream Aerospace's ongoing roadshow, demonstrating what it calls its Supersonic Acoustic Signature Simulator II ™ (SASSII) in an apparent attempt to change existing federal regulation on supersonic flight over the U.S. is any indication, an SSBJ might be close than we think. According to Gulftream, its research into suppressing sonic booms caused by supersonic aircraft has led to SASSII's development, allowing it to demonstrate the results of its research by simulating the sound of supersonic flight: the “Gulfstream Whisper.” Gulfstream says its SASSII demonstrator has traveled extensively -- from Savannah to California to Washington, D.C. The 7-by-11-foot audio booth comprising SASSII, featuring a custom arrangement of high-fidelity speakers and housed in a 32-foot-long trailer, allows comparing the sound of traditional sonic booms to the Gulfstream Whisper. To date, more than 600 individuals have participated in the demonstration.
Gulfstream says is "Whisper" is the sound a person would hear if a supersonic aircraft fitted with Gulfstream’s patented spike for controlling and reducing sonic boom flew overhead at Mach 1.8, a speed approximately twice that of today’s subsonic jets. “We’ve essentially taken the ‘boom’ out of ‘sonic boom,’” said Pres Henne, senior vice president, programs, engineering and test, Gulfstream. “Based on our analysis and testing, the Gulfstream Whisper is so indistinct that most people on the ground wouldn’t even realize a supersonic aircraft had passed overhead.” According to the company, its technology changes the sonic boom's sound wave, resulting in a softer sound, one quieter than the Concorde's by a factor of 10,000. "In most situations, the Gulfstream Whisper would be imperceptible, masked by ambient noises," the company said in a press release. “We need the scientific, environmental and legislative communities to hear the Gulfstream Whisper,” said Henne. “Their collective support in generating acceptance of this technological breakthrough is essential to removing the sonic-boom barrier to supersonic civil transportation.” Toward that end, Gulfstream says NASA in July granted four industry teams $1 million each to investigate the feasibility of developing a demonstration airplane that, when flown at Mach 1 and beyond, is sufficiently quiet to fly over populated areas. Gulfstream is teamed with Northrop Grumman on its own effort.