Supersonic business jets: Flights of fancy or soon to be reality?

Alud Davies
By Alud Davies January 10, 2014 12:30 Updated

Supersonic business jets: Flights of fancy or soon to be reality?

More companies are throwing their hats in the ring to announce supersonic business jets, but are they dreaming, or will they soon be reality?
The sun sets on Concorde in 2003 (Photo: David Apps)

The sun sets on Concorde in 2003 (Photo: Dave Apps).

For busy executives and bankers travelling between London and New York or Paris and New York, the removal of Concorde from commercial service in 2003 was a major blow.

Now stuck on regular airliners, former Concorde passengers faced doubling flight times, with a resulting loss of productivity. It also meant that on a regular London to New York round-trip, they faced the prospect of being out of communication for a further eight hours. And while that might not seem like a huge amount of time to most of us, for top level executives and bankers, eight hours could be the difference between making, or losing millions of dollars.

So for some people, Concorde was a time machine. In the morning you could leave London and arrive before you’d left, giving you a full working day in New York. On the way back, you’d be home in time for dinner.

But for all its time-saving wonder, Concorde had a problem; a big problem that ultimately stopped sales of the supersonic airliner from really taking off. In fact, despite receiving non-binding order options from the likes of United, American, Japan Airlines and even Iran Air, only 20 aircraft were ever built.

Concorde’s problem wasn’t a new one, but it’s a problem that’s plagued supersonic aircraft since their inception and unfortunately it’s a problem that doesn’t look like being solved anytime soon.

Breaking the sound barrierĀ 

Travelling faster than the speed of sound means breaking the metaphorical sound barrier. Having taken off and accelerated to this point, breaking the sound barrier itself creates a sonic boom, a wave of pressure that’s created as the aircraft speeds up.

Made up of a series of smaller pressure waves that merge together once the sound barrier is reached, a sonic boom is created when there is a sudden change in pressure. It actually occurs twice as an aircraft passes over, first as the pressure suddenly rises and secondly when the pressure suddenly returns to normal. In simple terms, this can perceived as firstly, when the nose of the aircraft passes through the sound barrier and secondly, when the tail does.

It’s this sonic boom that was Concorde’s downfall. It meant that the aircraft couldn’t fly over populated land, as the resultant effect of the sonic boom was capable of breaking windows in houses on the ground it had flown over.

As a result, Concorde’s routes – or at least the routes where time savings could be made – were restricted to those that flew almost exclusively over large stretches of water. London to New York, London to Washington and Paris to New York were the most successful.

Due to American resistance to Concorde using US airports, British Airways first deployed its Concorde’s to Bahrain, where the aircraft was restricted to flying supersonic for only a small portion of the flight. Air France, on the other hand, sent its Concordes to Rio de Janiero – via a technical stop at Dakar Senegal – on a specially lengthened runway that later served as the primary transatlantic landing site if the Space Shuttle needed to abort its mission a few minutes after blast off.

Concorde’s first revenue services were in 1976, with Air France and British Airways successfully choreographing their inaugural services to the second. The last service, a British Airways flight from New York, landed at London’s Heathrow airport in 2003.

Solving the sonic boom

11 years later – and despite millions being poured into research projects – are we any closer to solving the sonic boom problem?

The most-publicised efforts were carried out by the US private jet manufacturer Gulfstream and NASA, who between them collaborated on a project dubbed as ‘Quiet Spike.’

Using a 24 ft long retractable composite lance attached to a NASA F-15B, the spike works by sending three parallel shock waves directly to the ground, mitigating the usual shock waves formed at the front of aircraft.

The collaboration was pronounced a great success in early 2007. Gulfstream’s Pres Henn said: “The Quiet Spike has proven remarkably successful. This is a very exciting day for us; it marks the completion of a major flight test program, one that is critical to moving us forward in the development of a supersonic aircraft.”

We’ve yet to see a Gulfstream application using this technology, but that could be more to do with the world economic meltdown rapidly dwindling the market for such an aircraft rather than anything else. Still, it hasn’t stopped others coming forward to announce plans for supersonic business jets of their own.

Aerion and Spike: Supersonic business jets

Aerion Corporation presents an ambitious concept for a SuperSonic business jet and is currently looking for a manufacturer willing to build the aircraft. The Aerion SSBJ gets around the sonic boom issue by flying subsonic speeds over populated land. The company’s research into natural laminar flows mean that the aircraft can cruise comfortably at Mach .99, while its maximum speed breaks the sound barrier at Mach 1.6.

The aircraft would hold a maximum of 12 passengers and have a maximum range of 4,000nm – roughly equivalent to that of Concorde’s – which would allow the Aerion design to reach Europe from the east coast of the US.

Although Aerion began talking about the SSBJ in public in October 2004 – announcing a string of orders in 2007 – as of January 2014, no manufacturer has come forward to announce their intentions of building the aircraft.

An artists impression of an Aerion SSBJ in flight

An artist’s impression of an Aerion SSBJ in flight.

Hypermach Aerospace Industries isĀ talking to manufacturers about production of its SonicStar jet, which promises New York to London in just one hour. Another company that’s recently come forward with high-ambitions is Spike Aerospace, who in September 2013, announced that it is working on the catchily-named Spike S-512 SSBJ, scheduled to enter service in 2018.

Like the Aerion, the S-512 is meant to fly at subsonic speeds over land, opening up to a maximum speed of Mach 1.8 over seas. The S-512 also matches the Aerion’s 4,000nm range, promising to reach London to New York in three to four hours.

Spike S-512 supersonic jet

The Spike S-512 supersonic jet will have a maximum range of 4,000 nautical miles.

So, to answer the question raised in the headline of this, the answer is reality… but also fancy.

All of the SSBJ projects that have been publicly announced share one crucial theme in common: they can’t fly supersonic over land. Like Concorde, the range of city pairs that they can connect are very limited. The largest business aviation market in the world is the US domestic market, but to fly city-to-city in the US, you always fly over land, which makes supersonic speeds a moot point. Even in Europe, the vast majority of city pair connections don’t go anywhere near oceans.

The market is there, however, for transatlantic crossings. Concorde proved this. But 38 years since its first commercial services in 1976, we’re still having the same issues. And until those issues are solved, the dream of supersonic travel will remain a niche market that’s only available to the super rich.

Alud Davies
By Alud Davies January 10, 2014 12:30 Updated

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