The future of supersonic passenger planes without explosions

Advances in noise reduction technology could help supersonic passenger jets overcome the limitations caused by sonic booms.

AS2 supersonic passenger aircraft design

When the Concorde first took to the skies in the 1970s, it could fly from London, England to New York, America in just three hours. However, the development of supersonic passenger planes was limited by the loud bangs that would occur when they exceeded the speed of sound.

Recent advances in noise reduction technology, coupled with falling prices for commercial flights, could make supersonic passenger planes feasible within the next 10 years, according to Wired.

"It represents a contraction of the world, like the transcontinental railroad and subsonic aviation before it. It is also a sign of the reversal of the stagnation and slow innovation in the aviation industry over the past 40 years," said Samuel Hammond, a researcher at George Mason University in the US.

His research shows that the technology to build supersonic aircraft that do not emit sonic booms is well within reach.

"With lightweight materials, efficient engines, good computer modelling and more experience, we can create an aircraft that is both faster and cheaper than Concorde."

The discovery comes as technology companies race to design the first supersonic airliner since Concorde.

Startups Aerion and Spike Aerospace plan to launch their first product in 2023. In November 2015, Airbus announced that it was working with Aerion to build the AS2 supersonic aircraft, which can fly at speeds of 1,200 mph. The company said its AS2 aircraft would be capable of hypersonic travel, allowing passengers to travel between London and New York in just three hours, and Los Angeles to Tokyo in six hours.

The AS2 aircraft has a maximum speed of 1,931 km/h. Photo: Aerion.

It will fly at a top speed of 1,960 km/h, roughly the same as Concorde's 2,170 km/h. The team claims to have completed initial designs for the carbon-fibre wing structure, fuselage, landing gear and fuel system. The wings will reduce drag by up to 20%, allowing for reduced fuel consumption, increased range and a luxury cabin that can accommodate up to 12 passengers.

A key innovation is the plane's long, thin shape, which helps reduce noise as it flies above the speed of sound. In conventional supersonic aircraft, shock waves from parts like the nose and wings resonate into a powerful pressure wave that radiates from the nose to the tail.

As this shock wave travels through the ground, air pressure increases sharply, then drops suddenly, then increases rapidly again, causing a "double bang" phenomenon.

A longer, slimmer shape is best for generating weaker shock waves. “We see clear, achievable technical solutions for designing a supersonic jet, and a realistic path for Aerion to build and fly,” said Airbus vice president Ken McKenzie.

The AS2 faces competition from the Spike Aerospace S-512, a plane designed by a team of engineers from Boston. Both companies say their planes will be ready in just a few years.

The main competitor to the AS2 is the S-512. Photo: Spike Aerospace.

However, Dr Hammond points out that the aviation industry is being held back by a nationwide ban on civil supersonic flights imposed by the Federal Aviation Administration (FAA) in 1973. They have called for this ban to be replaced with noise restrictions.

"In 1973, the FAA banned civil supersonic flight in the United States, hindering the development of the aviation industry. It is time to repeal the ban and develop more reasonable and moderate noise standards," Hammond and his colleagues concluded.

According to VNE