NASA tests ‘quiet sonic booms’ near Isle
Two-week effort uses jets flying over Gulf to determine public reaction to the noise
NASA has begun a series of quiet supersonic research flights off the Texas Gulf Coast near Galveston to test how the community responds to the noise from a new experimental aircraft that eventually could cut commercial flight times by half.
The space agency on Monday began testing “quiet sonic booms” near the island community using F/A-18 jets as part of its Quiet Supersonic Flights 2018, or QSF18, campaign. The jets are flying over the Gulf of Mexico in a unique maneuver as part of a twoweek project to assess public reactions to the noise.
“QSF18 is a big step in NASA’s efforts to understand what is required for acceptable supersonic overland flight,” said Peter Coen, NASA’s commercial supersonic technology project manager, in a statement.
“This is the first time in decades that we have reached out to a large community as part of our supersonic research,” Coen said. “NASA has performed similar tests at our Armstrong Flight Research Center, using similar sounds created by the same F/ A-18. We’ve measured the noise levels and the impact on structures, as well as surveyed people for annoyance, to make certain that these tests are safe and wellplanned. We greatly appreciate Galveston’s interest and support.”
NASA officials hope the Galveston tests will help further the agency’s goal of perfecting supersonic flight — an elusive goal marred by previous efforts decades ago with the Concorde, an aircraft that could cross the Atlantic in just over three hours by traveling twice the speed of sound. It was eventually banned by federal aviation officials after residents complained about noise from the plane’s sonic boom.
The public response data that NASA collects will be provided to the Federal Aviation Administration for use in developing new rules about potential supersonic
passenger flights that could cut cross-country commercial flight times in half. Currently, the FAA bans these flights over land, in part because of concerns about how they would affect communities and infrastructure on the ground.
A quieter ‘thump’
The F/A-18’s supersonic dive maneuver starts out over the water. At around 50,000 feet, the aircraft are put into a special dive that still creates a regular sonic boom; however, when the sound reaches land, it should be heard as a quieter “thump” instead.
While the “quiet thumps” produced by the F/A-18 present no risk of causing physical damage to people or structures, NASA has learned that elements such as atmospheric turbulence and humidity can influence how certain areas may perceive the sound. NASA will operate a number of microphone stations in the area to match up the community’s response with the decibel level of each sonic thump.
The agency will be conducting community surveys to get feedback on the sound levels of the
sonic booms.
NASA recruited 500 volunteer residents in Galveston to participate. If they hear the thumps, they will define the level at which they were able to perceive the sound.
“Galveston is both honored and excited to be part of this project,” Galveston Mayor James Yarbrough
said in a written statement. “This is the type of project that motivates engineers and innovators.”
The data will be used to help NASA better understand successful data-collection methods for future flights using an experimental aircraft called the X-59 Quiet Supersonic Technology, or
QueSST, demonstrator. Starting in 2022, the X-59 will fly directly over yet-to-be-selected communities to collect data using lessons learned from QSF18.
‘Still rattles the windows’
The “quiet thumps” produced by the F/A-18 present no risk of causing physical damage to people
or structures.
A handful of Galveston residents posted on Facebook about the sonic booms on the first day of testing.
“I heard the ‘quiet thump’ this morning,” wrote Jeff Daniels underneath a Facebook post from the city of Galveston about the sonic boom testing. “It’s definitely much better than a traditional sonic boom, but I wouldn’t want to listen to it all the time such as regular commercial air flights. It still rattles the windows.”
Jerry Baker, another commenter on the same Facebook post, wrote, “I just heard LOUD boom. East end, near beach. Windows lightly rattled in this old house.”