Sonic boom or bust? Dreams of super-fast jet travel revival face headwinds

Reuters via Yahoo ^ | 12/22/2017 | Jamie Freed

[DFG]

Supersonic passenger travel, which died out with the Concorde's demise in 2003, will make a comeback by the mid-2020s if three entrepreneurial U.S.-based companies can make jets quiet and efficient enough to win over buyers and fliers.

Fifteen years ago, Boeing Co canceled plans to build the near-supersonic Sonic Cruiser, the last big attempt by a major manufacturer to speed up commercial travel.

Now Japan Airlines Co Ltd <9201.T> and Virgin Group are backing one of the three U.S. supersonic projects, Denver-based Boom Technology Inc, which plans a 55-seat all business class jet.

Lockheed Martin Corp is partnering with Aerion Corp to develop smaller supersonic business jets, with Spike Aerospace Inc also targeting the private jet market given many see the super-rich as the likeliest early adopters of supersonic travel.

[Regulator]

Interesting that one guy says the engine will be the problem.

That’s not the issue. It’s sonic boom attenuation.

Supersonic fanjets have been around for a long time and are relatively straightforward to design. The question is simply design point and cost.

Fuel is relatively cheaper now then in the late ‘70s or early ‘80s so that’s less of a concern. The pax on a plane like that aren’t going to be that price sensitive anyway - their time is what’s valuable.

The Sonic Cruiser was not supersonic either - was a transonic cruiser and made little sense. It would improve transoceanic durations by minutes, not hours. Boeing did the sensible thing and built the 787 instead.

But building and flying a supersonic bizjet or Business Class jet is a linear exercise governed by one real technological challenge. When the sonic boom signature is mitigated, these jets will be extremely popular.

And the boom problem will be solved.

[ClearCase_guy]

many see the super-rich as the likeliest early adopters of supersonic travel.

Ya think?

[EQAndyBuzz]

What’s the problem with the sonic boom? If you go supersonic 100 miles out to see, who is going to hear it?

[ontap]

Concord never turned a profit!!!

[mountn man]

Not true.

It was making a profit before the crash.

[irishjuggler]

Whenever I fly, I can’t help but marvel at the stagnation that has existed in the aviation industry over past half century or so. Other than personal video screens, smoking bans and a much cushier business class, commercial air travel is pretty much the same passenger experience I remember as a kid in the 1970s. Someone (Chuck Yeager?) pointed out a few days ago that from the Wright Brothers’ flight to supersonic flight was a mere 44 years. That’s a pretty stunning rate of innovation. The last 44 years? Meh.

[Lazamataz]

What’s the problem with the sonic boom? If you go supersonic 100 miles out to sea, who is going to hear it?

Fish.

We cannot annoy the fish.

[mountn man]

The problem is airports.

You’re limited to near ocean airports, and strictly transoceanic routes.
The Concorde was limited to NY runs, from London or Paris.
They also made some runs down to the Bahamas

Make a supersonic aircraft, with a mitigated boom, and LA to NYC, SF to DC, CHI to anywhere, Or London to Hong Kong, etc, become a reality. Thus more aircraft built, more routes run and lower operational costs.

[Magnum44]

I can’t help but marvel at the stagnation that has existed in the aviation industry over past half century

Some things are limited by physics. We can control the aircraft design, make them cheaper, more efficient, etc, etc. But we can hardly control the atmosphere around the plane that it must fly through. We might as well try to control the weather as try to harness shock waves in the atmosphere. God gave us a universe to explore (within its rule set). It will come as a disappointment to some that humans cant overcome everything. Some limits we will have to live with.

In the meantime I have to attend to some important business in 1955...

[ontap]

It was owned by the British government so it made a profit the same way Amtrac makes a profit.

[mountn man]

Do some research

Before spouting things you know nothing of.

Concorde was HEAVILY scrutinized over other aircraft operations. BA went private in the 80’s and BA bought out all governmental ties to the aircraft.

[irishjuggler]

God gave us a universe to explore (within its rule set). It will come as a disappointment to some that humans cant overcome everything. Some limits we will have to live with.

I tend to blame government (over)regulation more than God. Many, many physics 'barriers' that were declared insurmountable have been broken by human ingenuity and trial and error. But when the FAA and similar governmental agencies around the world have blanket bans on non-military supersonic flight, it discourages aerospace from even attempting to innovate in that area. It's a situation where your ability to test new technologies is artificially limited by the government, and even if you succeeded there's a strong possibility that you'd be legally barred from commercializing your innovation.

[ontap]

You have a propensity to let your mouth overload your brain...you should learn the art of how to disagree without being disagreeable. I don’t doubt your intelligence and you would fair better to give me the same courtesy!!!

https://www.youtube.com/watch?v=a_wuykzfFzE

[TalonDJ]

“That’s a pretty stunning rate of innovation. The last 44 years? Meh.”

Cars have not changed much either.

The exterior shape of aircraft is dictated by the air and was pretty well optimized early on.

If you pull the body off of cars from all the years since Henry Ford you might be surprised how little has changed.

There is actually a pretty stunning amount of progress that has gone into the cockpit of airplanes but most people don’t look at that, or don’t know what they are seeing when they look.

Go look up how many major plane crashes happened in the 1970’s and then look at the same numbers for the 2010’s

[Ozark Tom]

They claimed that man could not fly faster than the speed of sound. A wall existed that would kill any pilot that dared to go there. Then Chuck Yeager showed that their thinking was in fact an illusion, an adjustment of perspective would reveal a practical approach to achieve supersonic.

For now supersonic flight produces sonic booms and requires so much power that fuel consumption is horrendous. Only the military can afford to fly supersonic, and then only sprints between mid-air refueling points. Many claim the shock wave will always accompany aircraft travel faster than the speed of sound in an undisturbed atmosphere; but, who says we can’t tinker with the very air itself?

Richard Lugg has a vision of producing a turbine-electric hybrid propulsion system which has an ability to generate tens of millions of watts of electric power. With that power available, there are various ways to modify the properties of the atmosphere directly ahead of an aircraft, which then allows manipulating the atmosphere to disperse any shock front and concurrently reduce drag. Fuel aboard would then suffice for long journeys at multi-mach speed.

https://www.globalsecurity.org/military/systems/aircraft/hypermach.htm

https://patents.justia.com/inventor/richard-h-lugg

[Magnum44]

The lore of past was not physics based. If you can show through mathematics and physics how you would change the very physics you are governed by, then there is an argument to be made. While we certainly don’t know everything, not even by a long shot, there are some established physics. And physically, you can’t break the sound barrier without creating the shock wave that defines it. Exception, fly in space where the speed of sound is essentially undefined.

[irishjuggler]

Fair enough. You’re right. Aerospace manufacturers have made great strides with airliner safety. I was talking more from the point of view of the basic flying experience which really hasn’t changed much for the typical passenger (i.e., be herded into a cramped cabin, sit in a crappy seat, eat a crappy meal and take 4-5 hours to fly coast-to-coast). I get your point about cars not really changing much either, and aside from safety, comfort and various bells & whistles, there’s some truth to that. At the same time, I think that we might be starting to enter into a new era of rapid innovation in that field (e.g., with self-driving vehicles). I just don’t see that happening with air travel. I’m not expecting a fundamentally different experience 10 years from now. And, as I mentioned in a another post in this thread, I blame that on the heavy government regulation that exists.

[BobL]

” It would improve transoceanic durations by minutes, not hours. Boeing did the sensible thing and built the 787 instead.”

Hours, at least on US/Asia routes. Look it up.

[Regulator]

Mmm hmm

Well the rule of thumb was about 1 hour for every 3000 nm flown, and the original concept was looking at ~10,000 nm range.

That was revised down to about 6500 nm. So with everything pristine and cruising at M=0.98, you could make hours plural.

But that's not what happens, as the reality of trying to do that with the ranges mentioned drives you down a bit in Mach number and also pushes you into fanjets that were at the time on the edge of feasibility.

You are operating right on top of the highest wave drag rise regime in flight. If you could use higher bypass ratio supersonic fanjets and supercruise it would be better - go about M= 1.2 -> 1.4

This is all rather easily determined and you can read a good paper on it here: Martin Hepperle's paper

But as he notes and others will, you will also get killed on time to climb and descend since you still have to operate in the same airspace as the slower traffic, so the time when you can find yourself getting that 20% extra speed margin tends to be attenuated. Maximizing it by lengthening the trip forces you to cruise slower to extend range and...you lose the speed advantage (not completely).

So in the end...maybe better off by an hour and some change?

Would passengers pay such a differential for such an advantage?

Nah. Boeing knew it at the time. I had friends working in that group. It was a concept airplane and they all knew it.

Some people think Mulally was just pulling a feint on Airbus to keep them off track while they went after the 787 design. I dunno, don't think Mulally was that smart. Maybe. It just sounded promising at the time, if...if...if.

Designing transonic engines and airplanes is a real challenge. You oughta try it sometime, I did it for a living many moons ago. Lot more difficult then the simple equations may make it look like.

Boeing people know that. Someday we'll get SupSonic airliners, probably not too long from now. But not transonic. There's no point, and it's right in the rough spot.