Boom Aerospace Company Wants To Bring Back Supersonic Civilian Travel (bloomberg.com)

pacopico writes: A startup out of Denver called Boom Technology has just come out of stealth mode [by] talking-up their supersonic jet. It would carry 40 passengers and travel at Mach 2.2. The company claims that it's about 30 percent more fuel-efficient than the Concorde. Based on this, it could get its prices down to the equivalent of a business class seat on long-haul flights. At Mach 2.2, a trip from New York to London would take 3.4 hours. Boom is meant to start test flights next year out of John Denver's old hangar.

Comments

All they need is...

[Frosty Piss]

...billions and billions and billions of dollars in venture capital.

This sounds great

[jonwil]

If they can get the cost of a 3.4 hour transatlantic flight down to the cost of a business class ticket on a regular airplane on the same route, whoever flies these things will get a good amount of demand (one of the big problems for Concorde is that not enough people were willing to pay the premium vs a normal air ticket, if this new mob has solved it so its as affordable as a regular business class seat that problem goes away)

Re:This sounds great

[jandrese]

Think about this. You're talking about burning 5x as much fuel per person, but still charging them the same price? Oh, and the aircraft is being built from scratch so you have to put amortized R&D costs for a limited production aircraft in there as well? It's not like Airlines operate with huge profit margins today, so where is that extra fuel money going to come from? The more I think about this, the more convinced I am that it is a scam. They could just be hopelessly incompetent, but I'm leaning more towards scam.

Re:This sounds great

[iserlohn]

Actually, AF and BA raised the ticket prices after they bough the planes from the government for peanuts and made loads of profit operationally. The R&D and initial build costs for the plane was burdened on the UK and French taxpayers though.

Re:This sounds great

[legRoom]

I'm leaning toward drag scales with the square of velocity, so mach 2.2 is going to take about 9x the power of commercial airlines mach 0.7.

Lift is roughly proportional to the square of velocity, as well. This allows faster planes to fly higher, where the air is thinner and drag is lower.

Supersonic flight is less fuel efficient, but not really for the reason you think. It's actually because:

1. The type of jet engines (low bypass turbofans or turbojets, usually with afterburners) required to sustain supersonic speeds are 1/2 to 1/4 as efficient as the high-bypass turbofans that work so well for subsonic flight.

2. The maximum achievable lift-to-drag ratio drops significantly as the sound barrier is broken. (This is a totally separate effect from drag's v^2 scaling.)

The end result is that supersonic transports are inefficient, but not nearly as bad as you might expect - as long as they operate at extremely high altitude: 18 km for the Mach 2 Concorde, or 25 km for the Mach 3+ SR-71. Both of these aircraft achieved ranges about 1/2 half that of some high-endurance subsonic competitors (the 747 and the U-2, respectively), at the cost of somewhat inferior payload capacity. This is far, far better than naive v^2 scaling would predict (especially for the SR-71!), without accounting for the higher cruising altitude.

Almost as good as Concorde engineering

[Anonymous Coward]

Next we'll have a plane that goes almost as fast as the SR-71, and a space rocket that can lift nearly as much as Saturn V.

Truly incredible what we have achieved in the computer age in just 30 years.

Re:Almost as good as Concorde engineering

[headkase]

which is why a $100 Android phone is impressive even if it doesn't quite have the horsepower of a 1980s Cray supercomputer.

Actually, a typical smart-phone today kicks the ass of a late 1980's Cray Y-MP super-computer. Shh though, you see, those computers used to be used for certain cutting-edge physics verification calculations. Best if people did think about using a cheap smart-phone for that today.

Longer flights

[danbob999]

Wouldn't it make more sense on a longer flight, say between North America and East Asia?

Re:Longer flights

[Radical Moderate]

Yes, but the trans-Atlantic flights were pretty profitable. Makes sense to start there, then develop trans-Pacific routes. Although range is an issue, the Concorde's max was 4500 miles. San Francisco to Tokyo is 5100 miles, so you might be looking at a refueling stop, which could eliminate any time saved by traveling Mach 2.

Re:Longer flights

[legRoom]

Yes. Range is a big problem.

Standard high-bypass turbofans are very fuel efficient (effective specific impulse 6000s - 9000s) - but they don't work at all at Mach 2+.

This design must be using either low-bypass turbofans (3000s-4500s), or turbojets (about 2000s - 3000s). If they need afterburners to maintain cruise (as most supersonic designs do), that will reduce fuel efficiency even further (1600s - 2500s).

The longer trans-Pacific routes are already at the limits of what a subsonic high-bypass plane can do while carrying a large payload, so don't expect any supersonic transport to be able to compete there, with engines that are 2-4x less fuel efficient.

(Note for anyone tempted to rebut with quotes about the Concorde engine's "high efficiency": that's thermodynamic efficiency, not practical fuel efficiency. The relationship between the two is complicated for jet engines.)

Re: Longer flights

[legRoom]

Concorde was capable of supercruise, that is, sustained supersonic flight without afterburners.

Makes sense. The Concorde's range was very impressive, for a supersonic aircraft.

Also, burning fuel at twice the rate isn't a big problem when you're going three times as fast.

Halving the specific impulse does not mean twice the fuel burn - it means twice the fuel burn per unit thrust. Even at high altitude, supersonic flight requires sustaining higher thrust compared to subsonic, so the Concorde really was a lot less fuel efficient per unit distance covered.

I don't have precise numbers, but a quick look suggests that the Concorde burned fuel about 10x faster than the 737 NG (a subsonic aircraft of comparable range and passenger capacity). It also flew 2.6x faster, so that would make it 3-4x more fuel hungry per passenger-kilometer.

And lastly, oil prices have taken a dive recently. I know the situation isn't permanent, but it won't change overnight.

This could help a lot with ticket prices, but it doesn't help at all with range. Aircraft range is basically limited by how much fuel can be crammed on board, without making the plane too heavy to fly safely.

The only way the Concorde could achieve comparable range and passenger capacity to the subsonic 737 NG, was by being a much larger aircraft (180 tons versus 80 tons) with a higher fuel fraction (50% versus 30%?). This technique is expensive, and can only be taken so far. Even with no payload at all, the airframe, engines, etc. will still cap the fuel fraction at perhaps 70%; no plane based on the Concorde's (quite advanced) engines and airframe could ever fly all that much further than the Concorde did, unless it refueled on the way somehow.

30%?

[Bert64]

A 30% efficiency gain over a plane designed in the 1960s isn't terribly impressive... There was already a model B Concorde designed and ready to be built back then which improved efficiency and range... Coupled with new lighter materials, more advanced flight control systems, newer engine designs etc it shouldn't be all that difficult to get 30% or more.

Re:30%?

[Kartu]

If it wasn't difficult Concorde would not have been the only successful supersonic passenger plane.
Soviet Tu - 144 crashed at Le Burget avia show (and was built mostly out of fear that it could have military uses... actually it did).
US Boeing 2707 never took off.

The only company extensively using new materials at the moment is Boeing (in its Dreamliner).

PS
And, frankly, flying supersonic plane built by a startup? No thanks.

Re:30%?

[Kartu]

(As far as mechanics go), electric car is much easier to build, than conventional. Here we have the opposite.

You can't seriously compare consequences (and complexity) of potential problems/safety measures in a plane (and, oh, dear, not just any plain, bloody SUPERSONIC plane) to that of a metal box with 4 wheels that just rolls on the surface.

Re:30%?

[serviscope_minor]

The only company extensively using new materials at the moment is Boeing (in its Dreamliner).

The A400M is also made out of a lot of composites. Also, many airliners make use of composites in the tail and wings, but not the fuselage like the 787. I think the recent A350 is about as rich in composites as the 787.

Next year?

[chispito]

An aerospace startup is "meant to start test flights next year" of their supersonic jet prototype? The 1/3 scale prototype that doesn't yet exist? I'm more than a little skeptical.

Re:Next year?

[jandrese]

I'm more than a little skeptical. Either this tiny startup is so incompetent that they don't even have a basic grasp of the scale of the problem they're attempting to tackle, or it's a straight up scam. An all new advanced materials airliner ready to fly in 20 months? If this were some wartime thing and you had a fine tuned skunk works with a Kelly Johnson type at the helm and you had engines ready to go from a different division and an airframe you could modify and a prebuilt avionics cluster then maybe. For a brand new startup it looks outright impossible.

The almost complete lack of detail on their page is another huge red flag. As far as I can tell they have some computer render of a curvy jet and what looks like a scale model of a very old jet engine.

Re:Demand?

[jandrese]

To be fair however, that $5000/seat cost assumes that the supersonic jet fairy visits them some time in the next year and magically makes the jet appear.

This was already killed off by the US airlines

[gavron]

TL;DR - US airlines lobbied against supersonic travel over the continental US. Congress got the FAA to ban it. End of story. The rest is wishful thinking while ignoring the regulatory situation on the ground. (The original article has many inaccuracies and made up stuff... but hey, ads.)

Long Version
When British Airways and Air France pooled their resources to finance the entire Concorde project it was designed not only for UK/FR to US flights, but also NYC to SFO, and SFO/LAX to Asia and Oceania flights. Their projections were for seat prices about 1.5x regular first-class fares and travel 2-3x faster.

Fearing competition from these faster planes, US carriers lobbied the US Congress to forbid these aircraft, claiming that the sonic booms would be devastating to the people below, that air traffic control could not handle such fast aircraft, and that it would be unsafe. In reality, air traffic controllers handle supersonic (military) aircraft all the time, as they are allowed (with authorization) to exceed the speed of sound. As the majority of travel would be intercontinental even the sonic booms could occur over the ocean prior to turning inland to make the Mach-2 flight to the other coast. Finally, there were no safety issues with the Concorde, as it had yet to enter service in the US. Until its one fatal accident of ingesting FOD into its engine the Concorde had the unenviable perfect safety record -- unmatched by the conventional US air carrier services.

Concorde seats did not cost $20,000 (you *did* read the original article, right) they cost $5,000 to go JFK-CDG. Boom wants to compete with that with $5,000 seats. That price was keeping the Concorde full and this would too... but they'd need to do overland CONUS travel to make a profit. Those routes would require a change in FAA rulings. Also there was *NOTHING* about September 2011 that stopped the Concorde. It had long been shelved after the 2000 crash in France. (Seriously, the original article just wasn't paying attention...)

To start a supersonic program today is in some ways different than in the 1970s. Our technological advances are great; our computers and modeling and simulation are awesome. However, our litigious culture has become much worse. Our astroturf-root organizations and sock-puppet lobbyists have gone from mere industry mouthpieces to an entire industry of opposing anything "revolutionary" or "disruptive." Other than cute little ads that tell you a dollar razor is "disrupting the shaving industry", that the Segway is "disrupting the bicycle industry", or that the Occulus VR is disrupting the video game industry, you can rest assured that in modern over-regulatory-happy America it's easier to legislate against change now than have to explain why you didn't prevent it later.

Do these guys have a plan? Yes. Do they have a product idea? Yes. However, until they address the regulatory issues that led to the demise of the Concorde, there will be no market success.

Please note: If you like getting your facts from Wikipedia, please remember that it's a compromise of facts from everyone who chooses to edit it. That means that you're not going to find "The US airlines acted like spoiled children and pissed all over Concorde and bought Federal Legislators until Concorde left for Europe." It's still the way things happened. You're also not going to find "military flights can go supersonic any time they want" in there because there's a desire on the industry's part to leave us thinking that supersonic is just plain loud and dangerous. It's still the way things happen.

To get a better perspective (at least with only its one author's bias) I recommend these two books:
1. Concorde: The Rise and Fall of the Supersonic Airliner
2. The Concorde Story

Enjoy.

Ehud
P.S. I would love to see supersonic passenger travel back. It may start at $5,000 a head, but soon there will be deadhead flights, specials, two-fers, red-eyes, and we can fly from LAX to JFK in two hours (30 to get to the coast and transition to supersonic, 1hr flight, 30 to subsonic and approach).

Re:This was already killed off by the US airlines

[Solandri]

The "U.S. killed Concorde by prohibiting it from flying over land" theory is cute. But there were plenty of over-land routes in Europe and Asia that Concorde could've been flying even towards the end if it had in fact been economically viable.

The 1973 Arab oil embargo and subsequent spike in fuel prices is what really killed Concorde. Fuel prices climbing to 2.5x higher than when you began designing the plane, and 5x higher than design price within 4 years of first flight will do that to a fuel-guzzling plane.

Don't engineer near the limits.

[EmperorOfCanada]

One of the rules in engineering is that you really shouldn't engineer near the limits of your materials. For instance a modern day hammer is so well below what can easily be made with steel and wood that we don't worry about its reliability; even a 50% reduction in strength because of a flaw would still give you a pretty useful hammer, or if the person wielding the hammer is unusually strong, still not a problem . At the opposite end of the spectrum are the materials that go into supersonic or hypersonic transport. If the slightest thing goes wrong the whole thing will just turn to crap. There are all kinds of pictures of airplanes that had fairly catastrophic failures (Aloha Airlines Flight 243 where it went convertible) and the plane landed fairly well. In hypersonic flight a tiny failure would typically result in the thing turning into a meteor.

So the question is not if a hypersonic transport can be built, but if a rough and ready hypersonic transport can be built. The answer at this point is NO.

As was discovered with Concorde. The plane could fly under ideal circumstances but the Concorde that crashed wasn't that badly damaged as far as a 747 would have been concerned. This is why there are a zillion 747s and no more Concordes.

So the only way for these sorts of planes to ever make it to civilian use will be that ever greater testbeds are produced that prove the foolproof nature of the state of the art. A military transport would be a good start. Then when we see pictures of large hypersonic planes where huge bits are torn open and the plane successfully made it to the ground we will not only feel safe to fly in them, but the insurance companies will green light their future.

Another great example of this sort of engineering being at the very edge would be the damage done to the last shuttle where it was hit by foam. Then the minor damage from the foam basically burned the wing off on reentry. Again the same damage to a 747 might not have been noticed by the flight crew and only picked up when someone was looking at the parked airplane on the ground.