BILL READ FRAeS asks if there is a market for the return of commercial supersonic flight or are passengers really just seeking a more pleasurable travel experience?

Could supersonic aircraft return to commercial passenger service? (Boom Technology)

In April holiday travel company issued the results of a survey they had organised which claim that 80% of Britons said they’d book more long distance flights if times were shorter (

Also according to the survey 97% of Britons would welcome the return of supersonic passenger jets like Concorde while a third would refuse to travel anywhere with a flight time of more than five hours. The survey was based on the opinions of 2,643 people aged 18 and over who were asked questions surrounding travel and transport relating to holidays.

One of the questions was: 'Would you like to see the return of supersonic passenger jets like Concorde?' to which 97% of the participants said 'yes'. Of the 3% who disagreed 66% said that they didn't think they were safe while 21% said they thought they'd be 'bad for the environment'. People were also asked when they thought supersonic passenger jets would make a return to the world's airspace, to which the 77% said that they thought a service of this kind of would be available to the public 'within five years'.

Supersonic love affair

Concorde was always regarded as a celebrity aircraft . (E Gammie/Wikpedia)

While the survey did not ask the important question of how much passengers would be prepared to pay for supersonic travel - it nevertheless raises some interesting questions. Even 13 years after the retirement of Concorde, people are still in love with the concept of fast jet travel. Concorde was not just popular with aviation buffs and air passengers but also with the general public who never flew in the aircraft but only ever saw it looking up from the ground.

The key selling point of travelling on Concorde was that it was exclusive. Unlike conventional aircraft where only first class passengers got the best treatment, everyone who flew on a Concorde was special. Concorde passengers had teams of dedicated staff looking after them both on the ground and in the air. There were exclusive check-in and waiting facilities and passengers were treated as individuals.

Although luxurious, Concorde was not noted for the width of its cabin. (Daniel Schwen/Wikepedia)

Yet, despite its eye-catching iconic look, the Concorde design was noisy, polluting, hugely expensive to develop and was not always easy to make money from operating. Although luxurious inside, it had a very narrow cabin interior compared to the large personal space enjoyed by premium passengers on widebody aircraft.

Sons of Concorde

The proposed Antipode hypersonic aircraft could cross the Atlantic in under 30 minutes (Abhishek Roy)

However, despite these drawbacks, there is rarely a month goes by without some mention of some new ‘Son of Concorde’ or ‘Concorde 2’ project to revive the concept of supersonic commercial transport. However, nearly all these projects have been for much smaller supersonic aircraft designed for business executives and the ultra rich.

One of the major obstacles to the wider acceptance of SSBJs is that of the sonic boom created by the aircraft when travelling at speeds of over Mach 1. While the noise from a sonic boom is not an issue when flying over water, it is not acceptable when flying over populated areas - a problem that also doomed the wider acceptance of Concorde. However, work is being done to address this problem. Lockheed Martin recently won a $20m contract from NASA to undertake feasibility studies on the design of a supersonic aircraft which is quieter and more environmental friendly than Concorde but is not due to publish its findings until mid 2017.

The two most advanced SSBJ projects are from Aerion and Spike Aerospace. Aerion is working on the triple-engined 12-seat Aerion AS2 designed to fly at 49,000ft at speeds of up to 1,100mph. In 2014 Aerion entered into a collaboration with the Airbus Group to help develop the AS2. First flight of the AS2 is planned for 2021 with entry into service to follow in 2023. The second SSBJ contender is Boston-based Spike Aerospace which is developing the 18-passenger Mach 1.6 Spike S-512 SSBJ with first deliveries aimed for the early 2020s. Spike has conducted research into the sonic boom problem and has developed what it describes as quiet supersonic flight (QSF) technology to enable flying faster than speed of sound possible without the associated noise.

The latest project to propose a successor to Concorde comes from a startup company based in Denver called Boom Technology which is proposing to develop a 40-seat Mach 2.2 supersonic jet. Sir Richard Branson is reported to have options to buy ten of the Boom jets for Virgin.

There are also longer term proposals for ever faster passenger aircraft. UK Reaction Engines, which is developing its unmanned Skylon spaceplane is also working on the EU-funded LAPCAT project looking at the technology needed for a hypersonic passenger aircraft which could fly from Europe to Australia in two to four hours. Canadian industrial designer Charles Bombardier is also proposing ever faster concepts - the 75-seat Mach 10 Skreemr (which would be launched by a magnetic railgun) and the 10-seat Mach 25 ramjet-powered Antipode (fitted with detachable rocket boosters) which could fly the 3,459 miles from New York to London in 11 minutes.

Good news inside but bad news outside?

Spike S-512 SSBJ interior. (Spike Aerospace)

There is no doubt that building a new supersonic jet is technically possible. New carbon-fibre materials have been developed which enable aerostructures to be much lighter while computer simulations and advanced construction methods will greatly reduce development and construction costs. Cabin interiors could also be a step change up from those experienced on Concorde with such ‘second generation’ features as inflight entertainment and connectivity (IFEC) options, personally controlled lighting effects, seat-side TV screens, virtual windows, pull up tables, revolving seats and flat beds? However, passengers accustomed to carrying several items of carry-on luggage could find that there is no longer room to store them in the restricted space aboard a slim-line supersonic aircraft.          

There could also be other problems. Any new supersonic passenger jet will enter a world far different from than the 1970s with concerns about the welfare of the planet and accusations of conspicuous consumption by the 1%. Even when not flying supersonic, Concorde was a noisy aircraft - although the general public seemed remarkably tolerant of this aspect of its operation. However, environmental concerns over excessive noise and pollution from a future supersonic aircraft will not be absent. There is also the problem of air traffic congestion – it is no use in getting to Heathrow in two hours if you spend another hour circling the airport waiting to land. Shorter times spent in the air will also be no advantage if more time is spent on the ground getting in or out of an airport.

Expensive to build

The Aerion AS2 SSBJ has a price tag of $120m. (Aerion)

While a financial case could be proposed for a SSBJ where the operator has plenty of money, the economics of commercial supersonic flight are more uncertain. There are a number of variables that could change to the disadvantage of the operator - such as a rise in the price of fuel or an accident or economic downturn which reduces passenger demand. 

The new generation of supersonic business jets won’t come cheap. Aerion is marketing its SSBJ at $120m - considerably more than Gulfstream’s largest G650 business jet which sells for around $65m. The cost of a larger design would of course be much greater.

Larger aerospace OEMs have not had particularly positive experiences with supersonic projects. Boeing has got its fingers burnt twice, firstly with the cancelled 200 to 300-seat Mach 3 Boeing 2702 supersonic transport project of the 1960s and then again with the faster but still subsonic Sonic Cruiser of the early 2000s. However, Boeing has not abandoned the concept, as NASA’s supersonic boom wind tunnel tests, included a model of a Boeing supersonic design. Airbus’ involvement with Aerion’s SSBJ is interesting, although it is not directly involved with either the aircraft’s construction or marketing.

Could the moral of this be that, if it was easy to make money from civil supersonic aircraft, then we would have seen more built by now?

Expensive to operate

Could you fly supersonic for the same price as business class? (Boom Technology)

A second question is that of ticket prices. Blake Scholl, Boom’s founder and CEO, claims that round-trip tickets on the 40-seat Boom Jet between New York to London could cost around $5,000 - a similar price to business class on a conventional aircraft. However, how he will be able to afford to charge such prices for seats on a relatively small aircraft is a different question. Supersonic travel is expensive. To make fast aircraft profitable, operators need to charge premium fares - not just to get their money back for the high operating and purchase costs of the supersonic fleet but also to avoid diluting passenger demand for the airline’s subsonic flights.

Travel time vs the journey experience

Airbus recently launched its Airspace by Airbus cabin concept - but will it be enough to win over the third of Britons who don't want to fly long-haul? (Airbus)

Returning to the results of the survey, could faster aircraft make a difference? If asked the hypothetical question as to whether you would travel more if travel times were shorter, most of us would probably say yes but whether we could afford to fly supersonic in the real world is a different matter.

Another interesting result from the survey was that one third of passengers don’t want to fly more than five hours but what was not explained is why. For a business man or woman, it might be a case of ‘time is money’ but, if the survey was based on the opinions of ‘ordinary’ passengers, it could just be because they don’t want to be on an aircraft for any longer than they have to. Could the desire for speed stem from the fact that, for most passengers, the current air travel experience is one to be endured rather than enjoyed? While a few privileged passengers in first and business class enjoy the luxuries of extra legroom, flatbeds and individual ‘pods’, for those in economy, flying is often more of an uncomfortable ordeal coping with airport security queues, flight delays and restricted seat width and pitch.

So is faster really better? Is the latent message from this survey that passengers just want a better, more comfortable travel experience? Could airlines (and OEMs) encourage more people to fly by improving the travel experience for the ordinary passenger, so that the time taken in the air is no longer so important? 

On 26 May the RAeS will be hosting a one-day conference 'What Price Speed'? looking at some of these issues and the optimum speed for different aerospace applications.

6 May 2016