Why supersonic jet travel is set to take off again — fast

Updated on March 26 2018

A typical flight from New York to London typically takes around seven hours. That’s almost a third of the day spent sinking into mind-numbing boredom whilst sat next to someone you hardly know. “Time is money”, people used to say, and when 12 percent of flight passengers are business travellers, you know they’re not happy to know they could be elsewhere amassing their millions.

The Concorde famously cut travelling time by almost half by flying at supersonic speeds.

But what if that same flight could be done in just slightly over three hours? People used to joke about teleportation as the fastest means of getting around but unless we manage to break the space-time continuum, we have the next best thing. Supersonic air travel, which saw its demise alongside Concorde’s in 2003, will make a comeback by mid-2020s. That’s if three ambitious entrepreneurial aviation firms — with the mighty NASA — can garner enough investment and make jets quiet and pocket-friendly enough to win over buyers (and the government) again.

The faster, the better

While we’re talking about billion-dollar investments here, it shouldn’t be too hard a deal to cut. The demand for faster travelling are on the rise. Yes, new era of supersonic planes remains a concept for now, bullet trains are already a reality worldwide — and they’re getting faster.

The world’s fastest train — the Shanghai Maglev — runs 19 miles from Shanghai’s Pudong International Airport to the city’s outskirts at Longyang metro station via magnetic levitation. The trip takes only 7 minutes with top speeds of 430kph. In contrast, a car drive there would take more than half an hour, while the regular subway would take up more than an hour.

Hyperloop aims to change the way we travel, taking you to your destination at 700 miles an hour in floating pods within low-pressure tubes.

Across the Pacific Ocean, a manifesto published by Elon Musk five years ago on a system he calls Hyperloop aims to reinvent travel in a similar way, and it’s edging closer to reality. The retro-futuristic dream of travelling via vacuum tubes honestly sounds like a claustrophobia-inducing nightmare to us, but is heralded as the future of technology and travel. DevLoop — a 500-metre-long testing environment in the Nevada Desert — is a S$395-million dollar investment by Virgin Hyperloop One. If it works, it’ll provide a faster option than traditional train or bus systems, while easing congestion on the roads.

As the masses get more demanding with interstate land travel, it’s only a matter of time before the same impatience hits the air, and that’s when supersonic air travel will truly take off. Indeed, it’s strange to realise that we aren’t flying any faster now than six decades ago, when Boeing launched its 707 plane to the world.

As technologically superior as they sound, the aircrafts were already developed in the second half of the 20th century — fighter jets being the most common example. By definition, they’re planes that are able to fly faster than the speed of sound (Mach 1) and this requires design principles that are discernibly different than subsonic planes. Entering break-neck speeds require greater engine power and more streamlined airframes to combat the drastic surge of aerodynamic drag.

Challenging the speed of sound

The visible part of a sonic boom is actually air that becomes squashed by sound waves.

At sea level, supersonic jets will fly at 1,223kph. In contrast, the typical cruising speed for commercial passenger aircrafts averages 900kph.

This exceptional speed isn’t without problems. Sonic boom — the sound made by shock waves when an object travels faster than the speed of sound through the air — sounds similar to a loud explosion. Now imagine if every commercial plane in the sky made such a ruckus. While this can be easily avoided if the aircraft restricted its prowess to above oceanic regions or desolate deserts, it also means every populated area in the world will be precluded. It simply wasn’t convenient nor economical.

Very specialised design departments will also face a conundrum far more pressing than just making the plane look cool. For optimal performance, the aerodynamacy of an aircraft should vary with its speed — by theory.  So ideally, the vast spectrum of speed at which they operate at would require the aircraft to change shape during the flight. Then there was fuel economy — supersonic jets are notorious for gobbling a ridiculous amount of fuel.

The Concorde could fly faster and higher than any other commercial plane.

Take for instance the only commercial supersonic aircraft that ever existed: the Concorde. For almost 30 years, the plane rattled windows as it shuttled the rich and famous across the Atlantic in speeds previously unimaginable.

Inarguably the most exciting, fastest, and most prestigious commercial aircrafts to grace our skies, the 20 turbojets made were operated by British Airways and Air France for almost 30 years, its almost-flawless safety record only tainted by one hull loss throughout its lifetime.

Equipped with afterburners, the four Rolls-Royce/Snecma Olympus 593 engines could accelerate the aircraft up to a cruising speed of Mach 2 (twice the speed of sound). What made Concorde unique compared to most supersonic jets is that it could maintain that cruising speed without needing to have the afterburners switched on (otherwise known as supercruising). It could also fly higher than any other commercial aircraft, with a cruising altitude of 60,000 feet. Your subsonic commercial jet usually tops out at around 41,000 feet. To say that Concorde owned the skies then is an understatement.

The end of an era

As technologically-advanced as it was for its time, Concorde could not avoid the dreaded sonic boom. More than a nuisance, it was also a commercial problem when strict laws were enacted. In the end, the only commercial routes were London and Paris to New York, as well as Washington DC, Miami and Barbados. A number of other services did run through the years, including a London via Bahrain service to Singapore. Unfortunately, service in this region didn’t last long following complaints by Malaysia and India. While all the other routes change from time to time, only the New York service remained until its closure in 2003.

With a glitzy target audience that included important business executives and celebrities, Concorde was very expensive to fly on, mainly because it guzzled four times as much fuel per passenger than a standard airline. The cost of a return trans-Atlantic trip creeped up to over US$20,000 (S$26,300). What you got from that was a very small seat in a 2+2 configuration, with a decent sit-down French meal. Still, it was nowhere as comfortable as being in First Class on a Boeing 747. Luckily, you didn’t have to stay cramped for too long; in westbound flights, the five-hour time difference means you’d arrive even before you had left.

image gerard helmer
The G-BOAD Concorde, which proudly displayed the Singapore Airways livery on one side of the fuselage and the British Airways Negus livery on the other. (Image: Gerard Helmer)

High prices weren’t the only factor in its demise. Following the Air France Flight 4590 crash in Paris in 2000, consumer faith significantly decreased and inevitably, its demand too. On October 24, 2003, its swan song would be a British Airways flight from New York to London, a trip forever immortalised by journalists Jeremy Clarkson and Piers Morgan when they got in a fight and started throwing glasses of water at each other.

It was believed that commercial supersonic travel would’ve ceased to exist with Concorde, but recent years have seen a resurgence. Only this time, it’s the private aviation sector that gets to fly faster. The engineering expertise and costs of developing new technology, building test planes and then conducting test flights have proved too steep for mass-market commercial lines to bear. It’s also more viable that the planes are built on a smaller scale before being adapted for expansion into larger commercial carriers like Concorde.

As some tycoons find themselves spending more time in business class than their own couch at home, surely the thought of cutting travel time to as much as half is an attractive enough proposition to order a supersonic private jet. Companies that rely on shuttling between cities constantly will also benefit this enhanced mode of transport as a more time- and money-efficient way of getting around offices.

The race is on

In the four decades since Concorde first entered service, no commercial plane has flown faster, despite better technology. Today, a crop of start-ups are looking to chase the dream that should’ve been realised years ago. The renaissance is spearheaded by small companies like Boom Technology, Spike Aerospace and Aerion to create a commercially and technically viable supersonic jet.

The swanky interior of Boom’s jet looks worlds apart from Concorde’s.

Backed financially by Japan Airlines and the Virgin Group, Denver-based Boom Technology is planning a 55-seat all-business jet, claiming engine, aerodynamics, fuel storage and material improvements that will help make planes lighter and fuel efficient. It’s raised US$33 million (S$43.4 million) so far, enough to build and fly its first supersonic jet, the XB-1, or more affectionally known as “Baby Boom”. The S$262 million-dollar aircraft will aim to hit Mach 2.2 when it launches in 2023.

The Aerion AS2 will adopt technology from a F-16 fighter jet.

Aerion on the other hand is enjoying a headstart with the support of F-16 fighter jet manufacturer Lockheed Martin, so it’s no surprise it has the most advanced of proposed supersonic jet projects. It’ll work with GE Aviation to develop an engine based on a core used in F-16 fighters, instead of developing an entirely new one. The 12-seat plane will have a planned speed of Mach 1.4 (top business jets peak at Mach 0.9), and will make its first test in 2023, with entry into service in 2025.

Spike Aerospace’s private jet is capable of speeds that could take on a F-18 fighter jet.

Spike Aerospace’s S-512 Supersonic Jet first made the news in 2013, but the Boston-based company’s project is still a work in progress. Equipped with features such as newly-designed “delta” wings and a modified tail — which supposedly increases aerodynamic efficiency, reduces drag, and improves fuel economy — it’ll have a claimed maximum speed of Mach 1.8. That’s the equivalent of the F-18 Hornet military fighter jet’s top speed. As a business jet, the S-512 is sobering S$79 million away, but CEO and president of the firm, Vik Kachoria, strongly believes that “flying supersonic is clearly the future of aviation.”

But if there’s anyone more qualified to take on these three, it’d be NASA. In 2016, everyone’s favourite space agency began working with Lockheed Martin to develop a quiet supersonic jet design under the Quiet Supersonic Transport (QueSST) program. The experimental plane under this project is the Low-Boom Flight Demonstrator (LBFD) — a test bed for technologies that could one day be implemented on commercial planes. Its first test flight is ambitiously scheduled for as early as 2021, but may well become a reality now that the Trump Administration’s budget proposal for 2019 includes full funding for it.

NASA aims to break the sound barrier without so much as a small thunderous roar.

No surprise that the brightest minds at its Washington, D.C headquarters are on it. ”Future supersonic aircraft seeking to achieve a low-boom, such as NASA’s LBFD, will rely on a swept wing design in order to fly at supersonic speeds without producing a loud sonic boom,” said NASA.

Their solution isn’t to remove the shockwaves, but to change their paths to disperse the vibrations. Their target? 60 to 65 decibels per boom from the ground, “so quiet it hardly will be noticed by the public, if at all…like distant thunder or the sound of your neighbour forcefully shutting his car door outside while you are inside,”

The demand for business travel is growing every year (it accounts for a total global economic contribution of almost S$1.45 trillion dollars annually), so the market couldn’t be more ready for options. Ask many a seasoned traveller and they’d give up their plush, fully-reclinable first class seats and bottomless champagne for a flight that gets there in half the time. If the aviation world can deliver a fuel-friendly and less shock-inducing supersonic jet in the near future, perhaps the world will seem even smaller than it already is.