Tuesday, September 11, 2018

Supersonic jet maker’s planes won’t go boom: Aerion’s jet will fly just below supersonic when above ground, and then speed up to Mach 1.4 over water

Plans to launch supersonic commercial jet travel have long been hampered by a U.S. ban on such flight over land.

But rather than limit routes to transoceanic travel, Aerion, Corp. of Reno, Nevada, plans to push its AS2 supersonic business jet right to the limit — flying just a hair below supersonic when above ground, and then speeding up to Mach 1.4 over water.

Maneuvering around the rule will be crucial for the few companies that want to establish a market for supersonic business jets. Spike Aerospace Inc. of Boston is developing a needle-nose plane that would travel at Mach 1.6 and carry 12 to 18 private passengers. Boom Technology Inc. of Englewood, Colo., plans to build a 55-seat supersonic airliner that would have a ticket prices on par with business-class travel.

Today’s supersonic jet manufacturers hope to avoid the problems that plagued the Concorde airliner, which flew for the last time in 2003. The Concorde was ultimately doomed by high maintenance costs, a soft market for air travel after the Sept. 11, 2001, terrorist attacks, and its high ticket price — as much as $18,260 in 2017 dollars for a London-to-New York round-trip flight — which left many seats empty. Sonic-boom restrictions kept the Concorde on mostly transatlantic routes.

Technology improvements, including carbon-fiber composites known for their strength and light weight, could make the new jets more efficient. The Federal Aviation Administration has been working with other aviation organizations around the world to develop international noise and emissions standards for supersonic flight, but Aerion says its jet will be able to start flying without any rule changes.

“Part of our business case was we don’t require any regulatory changes to fly our airplane,” said Tom Vice, chief executive of Aerion, who previously was president of Northrop Grumman Corp.’s aerospace systems sector in Redondo Beach, Calif. “It’s hard to convince somebody to buy an airplane and say, ‘We’ll get the laws changed.’”

The company intends to sell its planes for $120 million each, a price that would allow the company to pay back investors and invest in new technologies, Vice said. That compares with the price of a high-end business jet, which can be $60 million to $80 million. Aerion believes the savings in flying time — it plans to cut a flight from New York to Tokyo by 1 hour and 57 minutes — will justify the cost.

“Time is our most precious resource,” Vice said.

Aerion said it has already sold 23 aircraft, 20 of which will go to Flexjet, a Cleveland company that offers fractional jet ownership and leasing.

The business jet market shows the most promise for supersonic jets because large corporations and wealthy individuals are more likely to pay top dollar to save time, industry analysts said.

“Speed is not that high a priority for a commercial airline,” said Ray Jaworowski, senior aerospace analyst at market research firm Forecast International. “A supersonic business jet would be the ultimate prestige aircraft.”

And it has to be luxurious, Vice said. Aerion’s AS2 plane will have a large cabin that can fit as many as 12 passengers, putting it in the same size category as the Gulfstream G550 or the Dassault Falcon 7X. The wider fuselage design is known in aviation jargon as a “double bubble” and will allow more foot space.

The aircraft will largely be made of carbon-fiber composites and is being designed to fly at Mach 1.2 without generating a sonic boom. The company has been working with Lockheed Martin Corp. on the air frame and aerodynamics since December.

Aerion had previously worked with Airbus Group on several design aspects, including structures and high-speed wind tunnel tests. That partnership ended last year. The European aviation giant wanted to learn more about how air flows over parts of the wing and was not interested in developing a supersonic business jet, said Bart Greer, an Airbus spokesman.

Aerion is also working with General Electric on the plane’s engine, which is composed of an existing engine core that was modified to allow for more efficient subsonic and supersonic flight, Vice said.

Developing an entirely new engine might deliver more speed, but it would be expensive, said R. John Hansman, professor of aeronautics and astronautics at MIT. “You’re paying a performance penalty for that, but it makes total sense.”

Aerion’s long-term plan envisions possibly developing a larger commercial supersonic airliner, which could start off as a 24-seater and grow to 100 to 150 seats, though Vice said that could be many years in the future.

In the meantime, the field is growing more crowded. Boom, whose supersonic jet would carry more passengers and is aimed at ticketed commercial service, has already secured a $10 million investment and a 20-aircraft pre-order from Japan Airlines, as well as pre-orders from British billionaire Richard Branson’s Virgin Group.

Original article can be found here ➤ https://www.heraldnet.com

1 comment:

Jim B said...


All solid bodies traversing air at > Mach 1 generate a shock wave (boom) no matter what.

The trick is to reduce the (boom) to an acceptable level. Streamlining goes a long way but the shock wave is still there, though by design can be reduced considerably.

The relatively thick cambered wings of subsonic airliners (and private jets) are generally limited to Mach 0.74 in cruise to avoid the transonic drag rise due to the flow accelerating to Mach 1 over the top of the wing, which if sustained, leads to shock induced separation (buffet and stall).

This is why most airliners cruise at ~440 kts at say FL30. which equates to about Mach 0.76 or so.

Go faster and this pulls the shock to the leading edge of the wing which re-establishes stability, but now one has a leading edge shock (above and below the wing) to contend with which is more intense, thus a bigger (boom).

Any faster than Mach 0.75, the fuel bill (ticket) goes up rapidly, but to some customers this is not an issue.