The X-59 supersonic jet developed by Lockheed Martin (which normally works on classified military projects) is set to halve flight times to Australia. Unlike Concorde, a breakthrough in sound reduction will allow overland flights. Concorde was limited to flying over water because its sonic boom meant it could only break the sound barrier away from population centres. But new technology means a sonic boom of 75 decibels, no louder than closing a car door.
Working with Nasa, Lockheed Martin plans to open up long-haul supersonic fights to all.
Earlier this month Qantas flew its first non-stop subsonic flight from New York to Sydney in 19.5 hours. The X-59, with a speed of Mach 1.45, would be able to cover that route over Europe, Dubai and the Indian Ocean in half that time.
The X-59 is the plane testing the technology to make possible Lockheed Martin’s Quiet Supersonic Technology Airliner (QSTA), a plane for around 40 passengers, flying at Mach 1.6.
Fares are set to fall from Concorde’s days, when a London-New York ticket was £5,774, worth £10,000 today.
Rivals are already in the wings.
Denver’s Boom Super-sonic has 76 orders (including Richard Branson’s Virgin group and Japan Airlines) for an aircraft flying at Mach 2.2 (1,687mph), faster than Concorde’s Mach 2.04 (1,565 mph) top speed. Boom plans a three-hour 15-minute London-New York flight but, restricted to flying over water, its routes will be similar to Concorde’s.
“Though a technological marvel, Concorde was a business failure,” said Peter Iosifidis, X-59 programme manager at Lockheed Martin Skunk Works in California. “Commercial success wasn’t the first priority, and that’s why not many were built.”
The QSTA will seek to meet the needs of passengers, builders and airlines alike.
“All three have to be satisfied for a commercial venture to succeed. The airline needs to make money, the manufacturer has to sell them and the passenger needs to be comfortable with the price,” he said. “Other producers are not addressing the noise issue. Flying a supersonic jet only over water is restrictive, the only benefit being the faster speeds. If you’re only flying fast from London to New York, can you sell enough tickets to enough passengers to make it successful? And, with our technology just around the corner, their shelf life is limited, too.”
The secret of the quiet boom is in the aircraft’s shape. Using Concorde-like wings it adds an extended super-sharp nose to send sonic shockwaves cascading along the aircraft.
Lockheed Martin thinks its quiet boom will convince the International Civil Aviation Organisation (ICAO) to change the rules. And it is being helped by Nasa.
“Concorde’s sonic boom was loud. You can understand how annoyed someone would be sitting on their patio and hearing it 10 times a day,” said Iosifidis.
“Even 10 years ago we never dreamed we could design an aircraft down to 75 decibels.”
Nasa is already working with developers to create hybrid-electric and hydrogen engines that would mitigate the fuel burn of supersonic flights.
After it is handed the X-59 in 2022, Nasa will conduct a two-year test over four US cities to see what people think. It will then make its recommendations to the FAA (Federal Aviation Administration) and ICAO. “We’d like to see regulations changed by 2025 or 2027,” said Iosifidis.
Air Commodore Dai Whittingham, chief executive of the UK Flight Safety Council, said: “Noise restriction has been tightening every decade since Concorde when people used to attend airshows just to hear the sonic boom.
“While Concorde used to be limited to flying the Atlantic, this will allow flights across continents. Add quieter hybrid electric engines and it really will be a game changer.”
Lockheed Martin’s Quiet Supersonic Technology Airliner (QSTA) is the shape of things to come. The sleek airliner will carry 40 passengers each side of a single aisle.
Cruising at 55,000ft with a top speed of Mach 1.6 (1,227mph) it will halve long-haul flight times. Features include a hummingbird nose, movable V-shaped tail and a cockpit with computer screens instead of windows, a design that delivers an almost silent sonic boom. This, says Lockheed Martin, is the key to commercial success as it will allow the jet to cross continents rather than just oceans.
If the ban on overland supersonic flight is overturned, the first passenger planes should be airborne within a decade.