NASA begins quiet supersonic flight series operations

victoria@aviationnews-online.com
By victoria@aviationnews-online.com November 7, 2018 11:34

NASA begins quiet supersonic flight series operations

NASA is inviting journalists to learn about the agency’s Quiet Supersonic Flights 2018 campaign during a media day event taking place on Friday, Nov. 9, in the Houston area. NASA’s Quiet Supersonic Flights 2018 series, or QSF18, will feature an F/A-18 flying off the coast of Galveston, helping NASA to confirm techniques for X-59’s future community response flights. NASA is testing ways to measure the community’s response to a unique acoustic experience.

NASA has recently begun flying F/A-18 research aircraft to perform a special dive manoeuvre that will create a sonic boom out over the Gulf of Mexico in such a way that residents in Galveston would perceive it as a quiet thump – that is, if they are able to hear them at all.

NASA has used microphones to measure the levels of these sounds, and has studied the thumps to confirm they pose no danger to people, animals or structures.

Normally, an aircraft flying at supersonic speeds (faster than Mach 1, the speed of sound) produces a sonic boom so loud that, today, commercial supersonic flight is prohibited over land.

NASA test pilots will fly an F/A-18 supersonic research aircraft in a unique manoeuvre that creates a quieter “thump.” Capturing how people and sensors on the ground respond to that sound is the goal for the Quiet Supersonic Flights 2018, or QSF18, campaign.

“QSF18 is a big step in NASA’s efforts to understand what is required for acceptable supersonic overland flight,” said NASA’s Commercial Supersonic Technology Project Manager Peter Coen. “This is the first time in decades that we have reached out to a large community as part of our supersonic research. 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 well-planned. We greatly appreciate Galveston’s interest and support.”

The F/A-18 is a typical supersonic aircraft so, in order to shush the boom, it will be put into a quiet supersonic dive manoeuvre. Starting out over the water at around 50,000 feet the aircraft will be 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.

QSF18 is unique for another reason. For the first time, NASA’s Johnson Space Center, located just north of Galveston, will provide critical support for a NASA activity is about flight but not into space. The center’s flight operations staff are part of the team supporting the QSF18 aircraft, pilots and other crew based out of nearby Ellington Field.

“NASA’s role as a leader into new frontiers paves the way forward towards new technologies, opportunities, and milestones across multiple endeavors, as we have always done throughout our history,” said Mark Geyer, director of NASA’s Johnson Space Center. “As our efforts also continue to expand our boundaries and capabilities in space, Johnson Space Center is proud to be working with our colleagues at NASA’s research centers at Langley and Armstrong, and to take part in the agency’s aeronautics research efforts to lead aviation into a new era as ‘One NASA.’”

In Galveston, community feedback data will be gathered through the use of a survey, in which 500 recruited volunteer residents, if they hear the thumps, will define the level at which they were able to perceive the sound. QSF18 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 directly fly over yet-to-be-selected communities to collect data using lessons learned from QSF18.

“Galveston is both honoured and excited to be part of this project,” said Galveston Mayor James Yarbrough. “This is the type of project that motivates engineers and innovators. In Galveston, we have a long and proud history of being involved in advances in science and technology, whether that’s in medicine, rail, or shipping. In this case, our residents will have an opportunity to participate in a study to advance aviation and the design of commercial planes that can break the sound barrier quietly. We’re excited to be a small part of it, and we’ll do what we can to support NASA and help ensure the success of this study.”

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, which may be heard differently from other areas. 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.

victoria@aviationnews-online.com
By victoria@aviationnews-online.com November 7, 2018 11:34