A Design to Block the Boom of Supersonic Flight

Supersonic flight, or the ability to fly faster than the speed of sound, has been a long-standing dream for many aviation enthusiasts and travelers. However, one of the major challenges of supersonic flight is the sonic boom, a loud and disruptive noise that is generated when an aircraft exceeds the sound barrier. The sonic boom can cause damage to buildings, windows, and wildlife, as well as annoyance and complaints from people on the ground. Therefore, most countries have banned supersonic flight over land, limiting its potential applications and benefits.

However, a new generation of supersonic aircraft that promises to soften the sonic boom problem was recently unveiled by NASA and Lockheed Martin. The X-59 Quiet SuperSonic Technology (QueSST) aircraft is an experimental plane that is designed to fly at 1.4 times the speed of sound, or about 925 mph, while producing a quieter sonic thump instead of a loud boom. The X-59 is expected to fly for the first time in 2024, after completing ground tests and validation. The ultimate goal of the X-59 project is to provide data and evidence to help regulators reconsider the rules that prohibit commercial supersonic flight over land, and to pave the way for a new era of faster and quieter air travel.

How does the X-59 reduce the sonic boom?

The sonic boom is caused by the shock waves that are formed when an aircraft flies faster than the speed of sound. The shock waves propagate in a cone-shaped pattern behind the aircraft, and when they reach the ground, they create a loud noise that can be heard over a large area. The intensity and shape of the sonic boom depend on several factors, such as the speed, altitude, size, and shape of the aircraft.

The X-59 is designed to reduce the sonic boom by modifying the shape and distribution of the shock waves. The X-59 features a thin, tapered nose that extends for almost a third of its 99.7 ft length, which helps to break up the shock waves and prevent them from coalescing into a strong boom. The X-59 also has a top-mounted engine that provides a smooth underside to block the shock waves from merging behind the plane. Additionally, the X-59 has a long and slender wing that reduces the lift-induced drag and the shock wave strength.

The result of these design features is that the X-59 produces a series of weaker shock waves that create a sonic thump, or a low rumble, instead of a sonic boom. The sonic thump is expected to be as loud as a car door closing, or about 75 decibels, which is much lower than the 105 decibels of a typical sonic boom. The sonic thump is also more localized and shorter in duration than the sonic boom, which means that it will affect a smaller area and for a shorter time.

How will the X-59 test the public perception of the sonic boom?

The X-59 is not only a technological demonstration, but also a social experiment. One of the main objectives of the X-59 project is to measure the public perception and acceptance of the sonic boom, or the lack thereof, and to provide data and feedback to the regulators and policymakers who can change the rules of supersonic flight over land.

To achieve this goal, the X-59 will conduct a series of acoustic testing flights over selected communities in the United States, starting from 2025. The X-59 will fly over these communities at supersonic speeds, while generating a sonic thump that will be barely audible to the people on the ground. The X-59 will also be accompanied by a chase plane that will record the sound and the shock waves of the X-59 from the air. Meanwhile, a network of ground sensors and microphones will measure the noise level and the impact of the sonic thump on the environment and the wildlife. The most important part of the acoustic testing, however, will be the surveys and interviews that will be conducted with the residents of the communities, who will be asked to share their opinions and reactions to the sonic thump. The data and feedback collected from these tests will be used to assess the feasibility and desirability of allowing commercial supersonic flight over land in the future.

What are the benefits and challenges of supersonic flight?

Supersonic flight has the potential to offer many benefits for the aviation industry and the society at large. The most obvious benefit is the reduction of travel time, which can save money, increase productivity, and improve the quality of life for travelers and businesses. For example, a supersonic flight from New York to London could take about three hours, instead of seven hours with a conventional subsonic flight. A supersonic flight from Los Angeles to Tokyo could take about five hours, instead of 11 hours. This means that travelers can spend less time in the air and more time at their destinations, or even make round trips in a single day. Supersonic flight can also enable new opportunities for tourism, trade, and cultural exchange, as well as for scientific and military applications.

However, supersonic flight also faces many challenges and drawbacks, besides the sonic boom issue. One of the main challenges is the high cost of developing, operating, and maintaining supersonic aircraft, which can make them unaffordable and unprofitable for most airlines and customers. Another challenge is the high fuel consumption and carbon emissions of supersonic aircraft, which can have negative impacts on the environment and the climate. Furthermore, supersonic flight also poses technical and safety risks, such as the high aerodynamic heating, the structural integrity, and the engine performance of the aircraft at high speeds and altitudes.

The X-59 QueSST aircraft is a groundbreaking project that aims to overcome the sonic boom problem and to enable the possibility of commercial supersonic flight over land. The X-59 is designed to fly faster than the speed of sound, while producing a quieter sonic thump that will not disturb the people and the environment on the ground. The X-59 will also conduct acoustic testing flights over selected communities to measure the public perception and acceptance of the sonic thump, and to provide data and evidence to the regulators and policymakers who can change the rules of supersonic flight. The X-59 project is expected to pave the way for a new era of faster and quieter air travel, as well as to offer many benefits and opportunities for the aviation industry and the society at large.