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The Concorde's baby - new supersonic commercial aircraft

They'll come up against the same problems. Unless the serfs are made to accept sonic booms over their heads while the patricians jetset around the world filling their boots
 
There are masses of hurdles to get over, not least the fact that most of the world bans super-sonic flight through their air-space. There is supposedly some clever engineering to reduce the sonic boom, but.................

As for CO2 from it - I believe that it is supposed to be flying very high (only possible long haul, which is the only circumstance where the speed would be of any use anyway), so do not assume that speed equates to increased emissions.
 
From that link in the first post:

"Boom has completed the design of the demonstrator and has started the build process, with plans to have it ready for flight by the end of 2017."

Er, they'll be missing that then.
 
Vinny said:
As for CO2 from it - I believe that it is supposed to be flying very high (only possible long haul, which is the only circumstance where the speed would be of any use anyway), so do not assume that speed equates to increased emissions.
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Can you explain that a bit more?
 
The simple explanation, that you probably didn't require, first - a large proportion of the flight would have to be super-sonic for the speed to significantly affect journey time. A flight that was as much take-off, climb, decent and landing as it was actual flight, would gain not much if anything.

The current crop of standard medium-large civil aircraft engines (high by-pass turbo-fans) are burning something like 20% less fuel than the equivalent engines of 20-30 years ago, for a whole raft of reasons in terms of design although they boil down to running hotter in the combustion chamber and turbines, and working at higher compression ratios. (That does nothing to offset the VAST increases in air travel however.)

Flying very high, air resistance is less, so requires less energy - that is simple maths, although you do have to get there and back and be able to actually fly in very thin air.
I have just seen that, very oddly, they are looking to use an ancient, very simple single shaft GE engine, most commonly used (as a variant with an after-burner) in military planes. That would make you think that fuel economy/emissions would be pretty horrible. Presumably the problem is one of cost for developing a new engine from scratch???? Educated guess for a new engine - $100,000,000???? More????
 
I expect the only engines designed for supersonic flight are military ones, and the one they've chosen is probably chosen on the basis that a) they can get hold of it, and get support for it and b) it develops sufficient thrust for the design prototype. It's been a while since I looked at jet engines in any detail, but my understanding is that high bypass designs are unsuited to either afterburning, or supersonic applications.

If you're designing a low-bypass turbojet for military applications (including high-g manoeuvres) I can see that the simplicity and robustness of a single-shaft design would be attractive. I believe, for example, that the gyroscopic forces in a sustained high-g turn will pull some engines apart.
 
Mach 2+ requires huge amounts of power, even at high altitude, say 60-80,000ft.

Their project seems to be aiming at Business Class customers. Are they willing to spend the company cash on such a luxury? Post 9/11, most of the world said no. But let's say there'll be enough customers. It'll be a big aircraft, swallow fuel, cost a fortune to maintain unless they get economies of scale from selling, say, 100 of them. Concorde was, for almost all it's life, a loss making halo product. If only made real cash when Joe Public started buying tickets for little trips across the Bay of Biscay etc.

If they can keep the overall weight down with composites and modern bonding techniques, then they might come up with a case for the elite to travel around in such a thing, but it won't be using too many European airports unless it can take off dry, not in reheat.
 
Sue Pertwee-Tyr said:
If you're designing a low-bypass turbojet for military applications (including high-g manoeuvres) I can see that the simplicity and robustness of a single-shaft design would be attractive. I believe, for example, that the gyroscopic forces in a sustained high-g turn will pull some engines apart.
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High G turns at supersonic speeds aren't generally a done thing. Typhoon can do it, but supersonic is pretty much only used for getting there, or getting the hell out.
 
Tony Lockhart said:
High G turns at supersonic speeds aren't generally a done thing. Typhoon can do it, but supersonic is pretty much only used for getting there, or getting the hell out.
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Yes. I wasn't suggesting high-g turns at supersonic speed, just noting that military applications are ones where both are likely to be within the normal operating envelope (albeit, as you say, not at the same time), and engines that do both are going to have to be robust, ie pretty simple.
 
Military engines, in military use, do cost a lot to maintain - that is part of the design - the components are designed to run at their absolute limits for relatively short periods - performance is almost everything, almost.

However, the proposed GE engine is already in use, in one form or another, in lots of civil aircraft so is unlikely to cost a great deal to maintain. What will be certain, is that they will know, very, very, accurately, what maintenance does/will cost.
I am unsure about other than large and medium civil engines, but they are sold at cost or a loss (yes, even at $7-10 million per for engines like RR Trent, that is a loss). Profits are made in repairs and overhaul, either as needed, or via schemes such as RR TotalCare.
 
I understood that many airlines now leased the engines on their fleets, on a 'power by the hour' basis including maintenance costs, rather than buying them outright.
 
Commercial aircraft may be bought by the user, or they are leased - one of the biggest lessors is GE. I wouldn't like to put a figure on it, but a large percentage of all civil aircraft are actually leased; only the very largest airline groups, such as IAG, actually buy aircraft.
Certainly for large civil aircraft, when an aircraft is bought, the engines are bought separately even if there is only one engine model approved for that model of aircraft. This is probably the case on smaller "private/executive" aircraft as well.
Irrespective of who buys the engines, airline or lease company, certainly in the case of RR, (and I would be surprised if GE, Pratt, Safran/CFM and Engine Alliance did not do similar) the buyer can elect to buy some form of engine care deal from the manufacturer. There are different levels of care deal but for new engines the full monty means that the user pays nothing after the deal is agreed - the manufacturer monitors the engines and ensures that they are running at maximum efficiency and the aircraft stays available for use, absorbing all the costs associated with achieving that.

I can't remember the time that the deals cover, probably 5 or 10 years?? Whatever, typically the care deal is much the same price as the engine - so a $10million engine would cost around $20million with the full care deal.
 
One factor that the aviation industry would be far better addressing would be the time spent on the ground going nowhere.

If I want to fly from LHR to anywhere at Mach 2.2, I have to brave the M11 or A12, the M25, then whatever link to the terminal. That's two hours minimum, but three to be reasonable safe. Then, how many hours at Thiefrow for security and having your baggage gone through, belt and shoes removed? Two or three? You then hopefully take off on time, but regs don't allow just going in a straight line to your flight path, more wasted time. You eventually arrive at your destination, wait an hour or so for your case to make its way through the thieves den and onto the carousel, and you can go to the rental car desk/taxi rank/train station. And wait.

Not really adding up, is it.

And if they're going to fly higher than 60,000ft, I think radiation comes into play.

Oh! And how will the crew see the runway when on approach? No mention of a droopy nose.
 
I expect that, like Concorde, this will be a first class only cabin, so limo from the front door, high speed check-in and discreet security will be the order of the day. At FL600 you can pretty much go straight to destination as a) you're above controlled airspace and b) who else are you likely to hit? I agree about cosmic radiation however, especially in a composite airframe. As to the lack of a droop nose, my guess is that they'll have some forward-facing cameras and project a virtual 'glass nose' for landing, a bit like the Land Rover 'glass bonnet' idea.
 
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