NASA conducts ‘quiet sonic boom’ tests for new airliner

By Chitwan Kaur

NASA, on November 1,  began conducting tests to check the noise levels emitted by a new experimental aircraft that promises to cut travel time by half.

These tests are being conducting in the Texas Gulf Coast to gauge the reaction of Texas residents to the noise created by the F/A-18 aircraft, as part of the Quiet Supersonic Flights 2018 campaign.The agency claims to have developed technology that creates ‘quiet sonic boom’, allowing the aircraft to break the sound barrier by avoiding the intense clap that normally follows.

“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.

The F/A-18 is being used experimentally to compare its impact on sound levels the X-59 Quiet Supersonic Technology aircraft which NASA claim will travel at double the speed of sound. Tests with the X-59 airliner are set to be held by 2022.

The agency claims that the noise made at 940mph or 1,515 kmph will be ‘no louder than the clunk of a car door closing’.

Source: Daily Mail

The data collected from the responses of the residents would be sent to the Federal Aviation Administration (FAA). The FAA is expected to devise rules for supersonic passenger flights. These flights, although they can potentially cut cross-country travel-time by half, are banned over land because of the damage they pose to people and infrastructure.

The F/A-18’s supersonic dive maneuver starts over 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.

Residents of Galveston, near Texas Gulf Coast took to social media to respond to their experience of the tests.

“I heard the ‘quiet thump’ this morning,” wrote Jeff Daniels on Facebook. “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 resident, wrote, “I just heard LOUD boom. East end, near beach. Windows lightly rattled in this old house.”

The X-59 airliner has been nicknamed ‘Son of Concorde’, after the Anglo-French Concorde passenger aircraft that could travel across the Atlantic within three hours. It was in operation from 1976 to 2003. The maximum speed at which the aircraft could travel was double the sound of speed.

The Concorde was retired from use because of the high cost of travel. After an Air France Concorde flight crashed, killing 113 people in 2000, sales of tickets to the aircraft fell dramatically.

The X-59’s precursor also posed the problem of noise pollution, the issue that NASA seek to tackle with the new airliner.