Is killing the boom the key to supersonic air travel?
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Firstly, all the big commercial investment has gone into sub-sonic planes, so they've gotten much cheaper. So to just have the same cost-ratio as concorde between supersonic vs. Standard flight is a big ask today. Secondly, Concorde wasn't just expensive -it was uneconomical because they couldn't fill the plane at those prices. Concorde was built in an era before deregulation - flights are far more cost competitive today. Thirdly, removing the sonic boom seems to imply inefficient shapes for the aircraft in terms of fitting numbers of passengers in. So even if the engines were far more efficient, you still have the fuel efficiency per passenger to worry about. For example Boom Supersonic are planning a 55 passenger plane. That is laughable as a commercial proposition.
I'm certain that companies working on this have concrete expectations of the cost o f a flight per person and the expected demand, I would just love to know what those are.
Do you feel that is too big, or too small? The market for supersonic travel is likely to align with the very high-end, private jet market. Those who want to get somewhere fast and don’t care what it costs.
It may be easier to overcome noise issues with a smaller design, too.
Cessna is killing the X, the fastest civilian airplane, in favor of slower airplanes. I'm not convinced that supersonic transport to/from major airports is going to threaten business/private jet aviation.
I see no reason this should not work.
There are 19K runways in the US, the vast majority of which have a longest runway under 4000'.
Make a supersonic aircraft too big and you risk not being able to find enough passengers willing to pay fares that make it viable - which is one of the issues that killed Concorde.
On top of that the top 0.1% is both larger and more wealthy making filling ~50 seats a flight at 30,000+$ a pop easier than you might think. Drop that into $5,000 territory and some people would this every week.
IMO it's actually business jets that are the best market. They fly fewer trips making fuel less of an issue.
But I would LOVE it if we could find a way to speed up the time spent at the airport. The amount of time I spend traveling to the airport, dropping off bags, queuing for security, getting pulled aside because I forgot I was wearing a belt that day, waiting for the gate to open, getting on a train to the gate, queuing to board the gate, getting on a BUS to the plane, queuing to get on the plane, waiting to put my overhead bags in the bins, waiting on the tarmac for the plan to find a free slot on the runway.
In the future I still have to do all this before we finally take off and travel at supersonic speed (yay), but then I land and basically have to do it all again.
Most of the time spent traveling by air is spent on the ground.
Train: Go to the station (near city center), arrive 10 mins before train departs, get on the train, read/work/eat/drink for 6 hours, get off the train. And then you are already at the city center of your destination!
The total time spent when flying might be shorter (4.5-5 hours), but that is not worth the hassle.
Uhm, flying is OK in terms of emissions per passenger mile. Not as great as train, but better than driving solo in a gasoline car.
The problem is transcontinental flights. While they're OK in terms of efficiency per mile, the number of miles is staggering.
The problem is, those trips can't be made by train.
So in terms of flying, I think the main focus should be not to fly long distance if it can be avoided. Sure, it's much better to take the train if possible, but if you fly between countries within europe a dozen times a year, that's not a catastrophe.
But as with all radically new technology, there needs to be a strong industry, government and consumer push. The program that produced the Methane turbofan concept (SUGAR Freeze) has lost any political appeal.
You can incompletely combust a 10-carbon molecule and wind up with other hydrocarbons but if you burn up CH4, you're definitely just getting one CO2.
Transcontinental flights (one side of the continent to the other, see [1]) can usually be taken by train. You probably mean intercontinental flights.
[1] https://en.wikipedia.org/wiki/Transcontinental_airspeed_reco...
But even if we could replace most <500 mile flights along the most popular routes (starting by connecting cities up and down the coasts), it would be a huge win as far as fuel economy is concerned.
The claim was that the trip can't be made, not that it can be made but is undesirable as compared with alternatives.
It was my understanding that driving is better for shorter trips, because the overhead of taking off and landing is significant. I don't have a source. IIRC I read this in "Doing Good Better."
They can't now, but they could be. All that is required is a level of capital investment that can't ever be recovered while in competition with air and sea-surface travel...
The transatlantic tunnel has been a sci-fi fantasy since 1895. It could cost as little as $500 billion today.
However the thing about flying is of course that it burns fuel at a much, much faster rate, so if it means the difference between you driving to workplace A vs. flying to workplace B regularly, then you'll be burning one hell of a lot more fuel by flying.
[1] https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft#Airli...
Hopefully, aviation can be electrified too one day (or it’s emissions reduced with hybrid technology), but unlike ground transport, the technology is not quite here yet.
It’s now just a case of getting costs down and infrastructure built out. But that’s the easy part.
Really? It seems to me that decent EV ranges are around 150mi right now, with the best ones going to 300mi... meaning they generally might get you halfway from (say) SF to LA, and you can bet that none of them will get you all the way. And that's not even that long of a distance, depending on what your standards are. Now charging times run into multiple hours, right? How is that even remotely close to gasoline?
The new generation of 350kW / 800V chargers will bring that down into the 15-20 minute range.
I realize I'm not most people (I love to drive), but this seems like it's bordering on extraordinary-claim territory. I don't actually expect evidence, since this would be the kind that's particularly difficult to gather (you could ask people, but what people say doesn't necessarily translate to what they do).
Regardless, it seems unlikely to me that anyone would want to be forced to take a break at the 4 hour mark rather than waiting for their destination at the 5 hours mark (e.g. SJ-LA).
I realize, of course, that it's just a matter of (not that great a) degree between 20 minutes every 300 miles for charging versus 10 minutes every 400 miles for fueling. However, because we're not even there yet for a comparably-priced/affordable electric car, it may be premature to think that way.
All those "shoulds" being forced on a consumer are likely to be disincentive to purchase, no matter how "bad" or irrational that might seem.
Considering that the vast majority of trips are within the 200-300 mile range of a modern electric vehicle, the fact that it's already "full" and ready to go every morning can be seen as a major advantage.
Not really, since this is a requirement of electric vehicles, too.
> the fact that it's already "full" and ready to go every morning can be seen as a major advantage.
That's not a fact but a speculation. It requires infrastructure at every vehicle owner's home (including adjacent, dedicated parking for every such vehicle!) that does not yet exist, for this to be true. (Substitute/add "workplace" for "home" may be slightly more likely but not for any specific vehicle).
A combustion vehicle owner could have similar infrastructure installed for liquid fuel, or hire a service to top vehicles off at night. It's too expensive, so "nobody" does it.
Is there even data that shows what proportion of commuters actually park in their garage, carport, or somewhere similarly electricity-adjacent?]
It's easy and inexpensive to install EV chargers at any home with a garage or parking space where electrical wiring can be installed. (In fact you don't even need to install a dedicated charger: you can charge an EV from any electrical outlet, if you don't mind slower charging speeds)
The vast majority of "typical suburban commuters" fit into that category, and they are the majority of car owners in North America and Europe.
OK, it's more of a challenge if you're an apartment dweller or live in a dense urban environment with only on-street parking.
But these are being solved, too: cities are installing kerbside chargers (including the ones built into lamp-posts that take advantage of existing wiring), and building regulations require new housing developments to include EV charging. Worst case, you can always make a trip to a nearby fast charger, but of course it's most convenient if you can charge at the location where you normally park anyway.
Dense cities like London and Amsterdam have exactly these issues, and it hasn't stopped an ever-increasing number of people from buying EVs.
Maybe today. Those are the early adopters. You're still speculating about a future that doesn't exist yet.
> It's easy and inexpensive to install EV chargers at any home with a garage or parking space where electrical wiring can be installed.
Are you a brochure for an EV/charger? :) The "where electrical wiring can be installed" implies installing electrical wiring, which is neither easy nor inexpensive (not in the US, as it will, for most people, involve an electrician and always, AFAIK, require permitting/inspection).
> if you don't mind slower charging speeds
It's not a question of minding but of whether it gets the job done of obviating the need for the separate fillup. If a Leaf needs 17 kWh for 50 miles, it would need 13 hours drawing 12A (max continuous for a 15A circuit) at 110V, which is doable but not exactly a long commute. 70 miles? Nope.
> The vast majority of "typical suburban commuters" fit into that category, and they are the majority of car owners in North America and Europe.
Which category, exactly, though? The one where they live in a neighborhood that merely has garages and carports? Or the one where they actually park every single car in a garage or carport space? (I live in a suburb, and the streets and driveways are pretty full at night.) Also, a majority of a majority can easily be a minority.
I still think you're speculating, and maybe wishfully thinking, without firm numbers.
> Worst case, you can always make a trip to a nearby fast charger
And again you return to the situation where an EV is no different than an ICE vehicle going to a fueling station.
> hasn't stopped an ever-increasing number of people from buying EVs
Without looking at (and showing us here) the actual numbers, from at least the whole of North American and Europe, "ever-increasing" is meaningless, especially when used in support of your original thesis that ground trasport will be largely electrified in the coming years (vanishingly unlikely) and decades (far more likely since you never specified how many).
Global car production, excluding China, is on the order of 70 million. I don't think non-hybrid EVs are even 1% of that, and the production growth has been closer to linear than geometric.
Even if 50% of new cars this year were EVs, I can't imagine that even in 10 years half the cars out there would be EVs. Assuming the current trend, though, for the Western world, it could be another 20 years before that 50% production mark, which means over 30 years before half the cars are electric. There's my speculation.
Other countries (China, Netherlands, France, UK) will follow as governments set mandates for electrification.
The US is likely be some years behind Europe and China on uptake for various reasons - there's not quite the same environmental imperative (air pollution) driving government policy, there's less tax on fossil fuels, and geography/demographics are not quite as favourable due to longer commutes and longer distances between cities.
But I do think we'll see significant electrification in many markets during the 2020s, with double-digit market share globally for BEVs by 2030 and >50% share in some markets (China, parts of Europe).
(btw: You do not need a garage or carport for EV charging. Chargers can be, and very often are in my experience, installed outdoors.)
The latter fails to support the former. A country whose entire population is less than the size of a large city can't be extrapolated, especially since so many other conditions (e.g. economic ones) don't hold.
> as governments set mandates for electrification.
This reads as future tense, so a speculation (upon which you're basing your speculation).
> But I do think we'll see significant electrification in many markets during the 2020s, with double-digit market share globally for BEVs by 2030
"Significant" electrification is still a far cry from your speculation of "largely electrified" ground transportation. 10% is enough for "double-digit", and that still corresponds to getting to 50% around the 50 year mark (assuming "market share" means cars on the road, not just new production).
> and >50% share in some markets (China, parts of Europe).
You really need to exclude China, or at least consider it completely separately, considering how the market is skewed in favor of centralized decision making versus consumer choices and freedoms. It may be interesting for any discussion of emissions, environment, availability of technology, EV competition on the global market, or anything like that, but not for consumer adoption elsewhere.
> (btw: You do not need a garage or carport for EV charging. Chargers can be, and very often are in my experience, installed outdoors.)
Again, "very often" fails to provide any actual numbers. Did you cleverly omit the qualifier "residential" from the above, just to make it true? Were they installed by (i.e. at the individual behest of) the residents themselves, without non-scalable subsidies/support? A government pilot program to spur the 1% early adopters by making it convenient to charge at home can have a politically bad smell if scaled to 10x.
As I said, in my experience, the vast majority of cars in my neighborhood are actually parked where installing a dedicated circuit (let alone a fast charger) is currently impractical, if not impossible. You can continue to speculate all you want about regulations changing or cities installing chargers in the middle of sidewalks, but, today, it's still fantasy.
Bottom line, today, BEVs are 1%, and ICE isn't going away, in large part, any time soon. Consumers who wish to make decisions based on emissions impact would do well not to just to buy into the marketing and wishful thinking of EV proponents and discount the impact of choosing driving (when there is a choice). Fortunately, the impact difference is also typically closely reflected in the price difference, at least for low-margin, high-competition markets (https://news.ycombinator.com/item?id=17578591).
If your destination is only 1 hour further away, then you're only going to need about a 10 minute charge, not the full 45 minutes. And you can stop pretty much anywhere en route where there are chargers available, it doesn't have to be at the 4 hour mark. Plenty of flexibility there.
"we're not even there yet for a comparably-priced/affordable electric car"
I agree, but they're getting close already when you consider lifetime costs including fuel and maintenance. And the more driving you do, the more financial sense an EV makes. That's why we're seeing taxi operators embracing EVs enthusiastically.
This is speculative and doesn't affect the emotional purchase decision today.
> Plenty of flexibility there.
Perhaps by some objective measure, but, again, that ignores the emotional component.
> but they're getting close already when you consider lifetime costs including fuel and maintenance
That's as may be, but lifetime costs are irrelevant if the barrier to entry (practical or emotional) is too high in the form of purchase cost.
It's not even necessarily irrational to decide to pay what appears to be a higher lifetime cost if ones personal "interest" rate in the TVM calculation exceeds the standard/average one, due to a high opportunity cost or just a high borrowing cost.
Companies including Airbus, Siemens, and Rolls Royce are actively working on this technology with a view to have working prototypes in the early 2020s.
Besides that, there is some "braking" energy to be recaptured during descent or when slowing the aircraft. This technology already exists today: The Pipistrel Electro can regen it's battery during descent. This is similar in principle to the ram air turbine (RAT) in conventional aircraft.
I wonder, does the efficiency gain from efans and a generator apply to a single engine setup as well as it does to multi engine setups?
Whenever I've spot-checked, the break-even is at 2 people, which tends to make flying more attractive for time/fatigue reasons (only barely, at some points in history) even for 2, and sometimes worth the cost premium for 3. For a family of 4 or more, even with the increased fuel cost (but generally not other operating costs) of something like a minivan, driving saves too much money to pass up.
You also can't hijack a train and drive it into a building.
Holding a plane full of passengers hostage is less foolish because the pilots/flight attendants can be bribed and bartered- it's not a technical impossibility to do certain actions, so there is more of an incentive.
While you can hijack a train, you can't fly it to a friendly country, and you can't fly it into a building, so it's a very different threat model.
Blowing up an airplane requires either bringing an explosive on board, or the use of a rocket-propelled grenade or full-on missile. Quite aside from the risks of hijacking mentioned in a sibling comment.
Please could you illustrate some of those for me, as compared to rail?
> Aviation is currently undertaxed, according to economists from the IMF and World Bank, compared to other forms of transport. Airlines pay no fuel duty and VAT is zero rated meaning that no tax is charged on sales and tax charged on inputs is refunded.
> ...
> CE Delft calculated in 2013 that the shortfall as a result of these two anomalies amounted to around €27 billion annually in Europe.
> ...
> At a global level, the World Bank and IMF favour a relatively low tax universally applied per tonne of CO2, which could then raise money for climate change mitigation.
> In the UK, the Liberal Democrat and Conservative coalition considered in 2010 replacing APD with a per plane tax to include freight aircraft and provide an additional incentive to airlines to fill empty seats. However, this was dropped following concerns, the Government claimed, about concerns that it could be challenged legally as representing a proxy fuel tax (contrary to bilateral air service provisions with other countries).
> Another alternative would be a form of taxation that discouraged frequent fliers.
2. Airports, particularly regional ones, are often owned by local governments and receive subsidies in order to encourage tourism and commerce in their region. In some cases, airlines receive direct subsidies from those airports in order to fly there.
3. Internationally, some airlines themselves are state-owned or state-subsidised. Gulf airlines such as Emirates and Qatar have been criticised for being significant beneficiaries of state subsidies.
This isn’t to say that rail isn’t subsidised too, of course. Even in countries where rail operates on a commercial basis, the physical infrastructure is usually government owned or financed in some way.
However, if airlines had to account for (and pay for) their environmental externalities, the costs of airline vs rail travel would work out very differently!
I expect that would also apply to international train tickets anywhere in the world. Policies on domestic tickets may vary.
But isn't this basically a road tax? Fuel for agricultural machinery or industrial plants is also free of such taxes (typically).
Plus first class tickets are like $20 more expensive than normal tickets and totally worth it.
Although I almost missed it because I'm used to all the buffer time you get with airplanes. Train leaves at 10:45, you better be there at 10:40 or you're gonna miss the darn thing.
One of my main issue is that train ticket are really expensive. Regional train are okayish, but TGV cost often way more than any other equivalent (plane/bus/car/...) and are sometimes not faster.
The second thing is that the network is historically completely centered around Paris. That lead to some very weird situation where, to go from the north-west to the south-west, you need to go all around France. And because of this, it is again faster and cheaper to just take a plane.
Finally, there is often delay or train being canceled, which is normal because lot more problem happen on the ground and such that when you are several thousand feet in the air, but they tend to communicate about it really badly. When your train have a problem, it is often really hard to know when you will have a new train, how much delay will you have, ...
On the other end, I agree with you. The train are so much comfortable. I really enjoy traveling in train way more than with any other form of transportation. I assume they are also a bit more ecological than cars and planes. The application of the SCNF to book ticket is also very good nowadays, never had a problem with it.
High speed trains do exist, or are being built, in more densely populated US regions (eg Northeast corridor, California).
The problem is, the regular seats are shoulder to shoulder, there's no showers, and everyone shares a bathroom. Plus, they gouge you relentlessly with food rates.
It doesn't seem like it would be a fun experience at all due to those conditions (but would be fun otherwise).
Of course you could spend $1,000+ each way to get a "sleeper seat" which comes with a shower and meals but then it's like you're essentially paying $700 for a shower and a touch of privacy. It's just off putting to me based on principle.
No one is suggesting that you take train from New York to LA but rather that you take a train from LA to San Francisco or Boston to New York. Similarly in Europe most people don't take a train from London to Rome but people will often take a train from London to Paris or Barcelona to Madrid. Any flight of 3 hours or less is usually faster and more comfortable as a train ride.
The whole duty free forced march -> endless tread mills -> gate -> bus routine is harrowing busy work. It creates multiple choke and synchronization points, thus multiple queues: you queue to enter the gate, than wait for everybody to board the bus, then queue again as people take their seats and place the luggage in the overheads.
It's a telling sign of how bad the current system is, when boarding on a single front door is considered a large speed up. A pod can take you to the right door in real time, gradually, as people arrive and clear passport control, overlapping multiple activities and allowing tighter turnaround. Why should the gate close 40 minutes before take off? If a passenger just checked in, and it takes 10 minutes for the pod to get to the plane, that's the minimal effective cutoff (with a larger official cutoff for safety).
As for passport and baggage control, those can be automated and sped up to a large degree using new technologies. And of course, the will of people in charge to change anything - I've spent to many hours waiting long queues while only 30% of the desks were manned, to know they just don't see queues as a problem. As for the duty free revenue this whole circus brings in, it must be massive.
> The whole duty free forced march -> endless tread mills
> -> gate -> bus routine is harrowing busy work.
Sorry, I do not really see how self-driving helps here, looks like a solution in search of a problem. Technology already changed a lot of things (self checkins, etc.) but it did not make flying a bit more enjoyable.
It's a historic design from the age of grass strips, that sprawled as modern airports grew to handle more and more passengers, increasing the walking and waiting required from one point to another to the current, extreme situation. We now have buses taking you to the plane, airport monorails taking you to the terminal (Frankfurt) [1], and even pods moving you around the airport (Heathrow). [2]
Self driving pods are the obvious response to unify all these transport needs in a single end-to-end system that can spread the passenger load in time and massively simplify the airport construction.
[1] https://www.frankfurt-airport.com/en/travel/transfer.detail....
Failures due to very specific processes are a typical situation now - I recently waited about 20 minutes when the transfer bus would no longer start, then wasted another 15-20 minutes because the replacement bus took us to the arrivals section of another terminal - while we needed to connect to another flight on the same terminal. Had to go through baggage control again, passports, had to wait for the Frankfurt monorail mentioned above, almost lost the connecting flight.
Seems to me a flexible fleet could improve this situation enormously with awareness of the passenger circumstances - even to the point of taking you straight to your connecting plane without visiting the terminal. Failure should be isolated to the affected passengers, short of catastrophic events where there is no routearound.
Also, airlines for some reason don't want checked in luggage, since they price it so high. This means everyone travels with maximum hand luggage, and boarding takes a long time. The last people boarding usually can not find space in the overhead bin close to their seat. I wonder if they really are at the global optimum point with this. Checked in luggage is also notoriously unreliable (it travels to the wrong country or is thrown around with such force that everything is broken) which can ruin your trip.
If I have no suitcases to drop off, and it's at a quiet time, then I can arrive half an hour before departure, breeze through security, and get on the plane.
But if I have cases, or security _might_ be long, then I'm having to leave at least an extra half an hour in case of big queues, if not an hour. And that's a time-killer.
The "automated bag drop" that some airports do now has really sped things up, but I'm sure some more time could be cut there. Security is the main bottleneck nowadays.
The bad news is that political changes need the cooperation of large groups of your fellow citizens.
Noise around airports was also a very contentious issue - low-bypass jet engines and, especially, the use of afterburners on the takeoff roll. This will become an issue again even if the sonic boom problem is solved. Smaller aircraft may be quieter, but they are unlikely to be welcome at airports that cater primarily to business jets, if they are any louder than those in use now - and the trend is towards quieter.
If it takes me 45 minutes to get to the departure airport, where I have to be one hour ahead of time to get through baggage check and security, and it takes 2 hours to get to my destination from the landing airport, then cutting a 4 hour flight to 2 hours is only 34% faster.
Like, fix the transportation and traffic problems around the airports and the logistical delays first, then brute-force the actual flight time.
Why this sequence and not the other way around, or both at the same time?
The two don't seem to be competing for any resources, other than the highest-level ones like money. In some cases, the airport logistics problem may be intractable or take too long (witness BER).
I also suggest your times are slightly off, in the context of the target market. I doubt someone paying that much would need the full hour (though as little as 30 minutes might be a stretch if we're counting departure time not boarding time).
I also think, however, that lowering a 4 hour (gate-to-gate) flight from 4 hours to 2 hours is unrealistic, and is too short a flight to make sense for supersonic, anyway. IIRC, Boom was looking to halve the 7-hour JFK-LHR hop, comparable to Concorde.
Where it would seem to be far more attractive is the much longer flights, such as trans-Pacific, where the overall time is much longer, a higher portion of gate-to-gate (and door-to-door) time is at maximum cruise speed (shaving 8 hours off a 14+ hour SFO-SYD could save a full day of travel). Even Europe to the US West Coast would be significant, which relates to the premise of the article.
No. Cost is
But, cost above everything. You can't get economies of scale for an SST with even less than double the cost of regular business class.
Cost is really the thing though. Produce a modestly-sized supersonic jet that can do trans-Atlantic and equivalent routes that are profitable with business class-priced seats and you probably have a market.
Probably. A lot of business class seats today are filled with upgrades and I believe BA has actually cut back on the business-class only routes between NY and LCY.
In other words, it is not happening.
Totally okay with that. The rest of the world can pay for vastly increased maintenance costs in neighborhoods around SST airports for the benefit of the rich few who can actually afford to fly on those planes.
I know nothing of aerodynamics but what I do know is that innovation in aerodynamics is more likely to come from the world of F1 than the bowels of Lockheed Martin these days. This has actually been the case since the 'Gurney Flap' that was the first innovation in aero to come from motor racing to make its way to regular aerospace.
In 2017 at the Singapore Grand Prix the Force India F1 team surprised the fans with a new gadget to get extra downforce. In 2017 F1 cars had a 'sharkfin' engine cover and on top of this Force India had what looked like a hedge trimmer, this was 30 or so very small wings that worked together to create two powerful vortexes with the mini-winglets reinforcing the same vortex created by the mini-winglets at the front of this 'hedge trimmer' arrangement. From this they were able to get good downforce from an area of the engine cover/sharkfin that was not supposed to be downforce creating. The innovation obviously had to be banned and this is no longer a feature in 2018 cars.
F1 max speeds are lower than a plane and the aero is not about getting airborne, however, due to the rules there is constant innovation. Regular planes look as aerodynamically sophisticated as F1 cars from the 1980's. I suspect that to do supersonic without the boom then aerospace will have to borrow more than just the Gurney Flap from F1. Furthermore, incentives have to be better than pork barrel politics or else the Lockheed Martins of this world will be on this gravy train forever.
That's not to say cars won't have an effect on the design. Two avenues I can think of in particular are:
1) Concorde's shape made it _extremely_ noisey upon take-off. That's subsonic travel, so other subsonic vehicles might provide design inspiration (even though in some cases going supersonic may mean the inspiration has to be ignored) 2) Projects like Bloodhound SSC might provide inspiration.