Flexjet orders 20 supersonic business jets from from Aerion
 

Beginnings of a new supersonic era?

Notably, if the Aerion AS2 flies at Mach 1.2 at or above FL350, its sonic boom will not reach the ground -- possibly allowing supersonic flights within the continental US and Europe, in addition to oceanic flights and regions with no supersonic restrictions (notably China).

Read more at Reuters

Can someone with more theorical knowledge than I do explains this ?

I also fail to see the interest to fly at M1.2 compared to a Citation X at M.9 at 1/5 th of the price.

Sonic booms and mach 1.2
 

A simple explanation of why the sonic boom does not reach the ground when at Mach 1.2 above FL350 is found here:
Quiet Supersonic - NASA Chases Fleeting Booms | Things With Wings

Cubemaster

Thanks cubemaster. very interesting , we'll see if those "evanescent waves" are acceptable or not to people on the ground , but the schema in the article raise another question : would the reflected wave be perceided by following aircraft flying behind/below ?

It's supposed to cruise at M1.4-M1.5 over water. Still not quite Concorde, though.

Maybe a Tech Log question, but is there a good (technical) reason why Concorde couldn't have done that ?

"It's supposed to cruise at M1.4-M1.5 over water. Still not quite Concorde, though."

it would still spare an hour or two on transoceanic flights, in business world that might be worthwhile

Smells like a PR stunt to me. Mach 1.2-1.5 has huge transonic drag and the massive additional fuel consumption will eat away you range, which is not worth the marginal overall speed increase. At least not for a significant number of aircraft to make the development costs break even.

I wondered when this old chestnut would come around again. Massive airships and personal jet packs will be back again sometime as well....:ugh:

Aerion AS2 will be the first production aircraft to employ a Supersonic Natural Laminar Flow wing, after apparently successful tests with NASA demonstrating an SNLF airfoil at high Reynold numbers suitable for a commercial jet.

A laminar flow wing significantly reduces drag, up to 90% reduction compared to current supersonic wings. The reduction in total drag (including other parts of the aircraft) is more modest -- predicted to be around 20% -- but that's enough to make supersonic flight economical.

Aerion's airfoil was able to simultaneously maintain laminar flow while shaping the sonic boom to enable quiet flight.

If the 12 people that you are flying are paid in the order of $10,000 an hour or more, then the sums may well add up for the companies using seats on such a biz jet as a journey need not take a full working day out. Add continual Internet over SATCOM so work can be done during flight.

You can be sure that the beancounters will have worked out the comparative costs of travel by different means, including down time while traveling.

What might be in the rear half (approximately) of the fuselage? - just something to hang the wings and engines on?

With AS2 an executive might have morning meetings in New York, then head to London to sign a deal, then make it back to New York in time for dinner & daughter's piano recital that evening.

When you're a billionaire, why not?

I know about a couple of people which are looking into a A340 Private Jet. O.K the aircraft is rather cheap, but the cost for conversion and the tco :} or think about what people are willing to paar for the Gulfstream G650
From my point of view the market is there.

Also, whilst there are a couple of jets that cruise at 0.9+, how many actually do it more than once after they see the fuel consumption?

The current "fast" jets are mostly top trump machines themselves.

There are a fair number of "cost is no object" people out there - Boeing has delivered over 200 Boeing Business Jets (including seven 777, nine 787, and eight 747-8) and the cost of the custom interiors is typically similar to the cost of the airframe.
It's long been speculated that the next supersonic passenger aircraft would be a business jet - this would seem to confirm that.
All that being said, I'll believe it when I see it. There are some major regulatory challenges (today's regulations are far removed from what Concorde was certified to), and the greenies will certainly have a hissy fit over the environmental impact and carbon footprint of a supersonic toy.

Every time I see a picture of the Aerion AS2 I think "Douglas X-3 Stilletto". The Stilleto configuration (long skinny fuselage with high polar moments and really short wings) had severe inertial coupling problems at high speeds. Joe Walker barely survived an inertial coupling episode in the X-3. How is Aerion overcoming this problem which is inherent to that configuration?

As the Air and Space Smithonian website says:
Every research aircraft poses a question. Sometimes the answer is "forget it."

The X-3 Stiletto | Air & Space Magazine

http://www.themanufacturer.com/wp-co...AS2-design.jpg
http://www.diseno-art.com/news_conte...Stiletto-6.jpg

Then there was the Lockheed Starfighter.

We've had unstable aircraft with computer-controlled control surfaces for over 40 years, the inherent inertia coupling tendencies will be controlled by that same philosophy.

The X-3 was designed in the late 40s/early 50s and hence couldn't benefit from small lightweight digital computers because they were not developed until 15 or more years later.

Just read the remainder of the X-3 Wikipedia article. Quite sobering. 260kt take-off speed and +/-7g roll-coupled pitch oscillations on the flight where Joe Walker nearly lost control.

The Aerion is real enough - a friend of mine, one of my instructors, is a senior engineer on the project. Lots of interesting stories... (not to be repeated here I'm afraid).