8 ms·

Is killing the boom the key to supersonic air travel?

53 points by bauc 8y ago

fabricexpert 8y ago
I would like to see supersonic travel come back. 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.
- struppi 8y ago
  This is exactly the reason why I usually prefer a 6-hour train ride to a 1-hour flight (at least in Germany, Austria, Switzerland). 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.
  - toothbrush 8y ago
    So much this. Not to mention the reduced environmental impact. Flying is absolutely catastrophic in terms of greenhouse gas emissions, and the Paris accord doesn't cover even a fraction of it! (because flying occurs in "international space" and so it doesn't appear on any country's "balance sheet"... atrocious.)
    - audunw 8y ago
      > Flying is absolutely catastrophic in terms of greenhouse gas emissions 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.
      - llukas 8y ago
        Is it still competetive vs car for supersonic flight?
      - cornholio 8y ago
        I know Boeing proposed Methane turbofans, and they were estimated to have 60% less carbon emissions and cheaper than jet fuel - after eating the large development and infrastructure costs. You could take this even further, producing Hydrogen from clean electric energy is about three times more expensive than methane for the same energy content, leading to a moderate increase in the cost of even a low cost ticket. 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.
        erezyehuda 8y ago
        Costs aside, wouldn't replacing carbon emissions with methane be drastically worse? Doing a casual search says that methane is 2000-3000% more potent as a GHG.
        ufo 8y ago
        I assume the methane would be the fuel, not the byproduct.
    - mehrdadn 8y ago
      I'll point out that although it's indeed atrocious compared to a train ride, flying is still more efficient than driving a car. So if traveling is required and you're debating between driving vs. flying (say SF <-> LA), you should prefer flying unless you can carpool. I don't know the exact numbers since it depends on where you're going and what plane/airline you fly, but I would expect around 50-75 MPG for a reasonably full airplane [1], whereas your car might be more like 25-30 MPG on the highway, so you'd want at least 2-3 (ideally 4) people in the car to make it more efficient. 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#Airlines https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft#Airli...
      - Reason077 8y ago
        That’s true today. But in the coming years and decades, ground transport will be largely electrified and it’s per-mile emissions greatly reduced. 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.
        mehrdadn 8y ago
        With battery capacities being what they are you'll also have to hang tight for the moment when they stretch long enough to allow you to even have the choice of driving to the same place you can fly. (Or swap batteries on the way somehow... not sure how well that would work.)
        Reason077 8y ago
        This is already solved in technology terms. Battery capacities and charging speeds are already good enough for almost all long-distance travel scenarios. It’s now just a case of getting costs down and infrastructure built out. But that’s the easy part.
  - kiba 8y ago
    All these security for air travel but not for a train which is also full of lot of people felt bizarre.
    - dijit 8y ago
      You can't hijack a train and take hostages to some other country; This was endemic in the 80s. You also can't hijack a train and drive it into a building.
      - amelius 8y ago
        But is this still true for airplanes, given the switch to hardened cockpit doors?
        Uberphallus 8y ago
        Then you get Germanwings incidents
        amelius 8y ago
        Which can't happen on trains and buses?
        endymi0n 8y ago
        Buses, maybe. Trains: Nope. Doors are locked from the inside, usually aren't accessible while moving and even someone would get inside, well, you can't get off the tracks. You'll get a red signal and a forced braking shortly afterwards. It's really, REALLY hard (by design) to wreck something on purpose with a modern high speed train.
        Uberphallus 8y ago
        And in buses you can't really lock yourself out as a driver.
        8y ago
  - Numberwang 8y ago
    I'm totally with you, but it is truly annoying the amount of subsidies the flight industry get. I've often taken trains across Europe due to my preference, but when the plane ticket is €20 and the train ticket is €400 it seems I'm fighting against the system.
    - peteretep 8y ago
      > but it is truly annoying the amount of subsidies the flight industry get Please could you illustrate some of those for me, as compared to rail?
      - yrro 8y ago
        UK here. > 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. https://www.aef.org.uk/issues/economics/taxation/ https://www.aef.org.uk/issues/economics/taxation/
      - Reason077 8y ago
        1. International airlines pay no tax on aviation fuel, despite their significant contribution to air pollution and climate change. In say, Europe, this represents a huge subsidy compared to ground transport, where fuel is heavily taxed. 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!
  - Swizec 8y ago
    I traveled with the French TGV a couple times and it is absolutely astounding how amazing it is. Large comfy chairs, quiet train, you can walk around, plenty of room for activities. There's even a bar where you can hang out with fellow passengers! 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.
    - maeln 8y ago
      Although I like our (maybe not for long) nationalized train system, I still have to mitigate your praises a bit :) . 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.
  - garmaine 8y ago
    Lol, try living in California. 6-12 hour plane ride to anywhere. Trains? We have them. But why would you when it takes literally days to cross the country.
    - dewey 8y ago
      That's not a problem of trains it's a problem of the US train infrastructure. As you can see in Europe or Japan trains can be very fast and very efficient.
      - Reason077 8y ago
        Sure, but the distances between cities in a huge country like the USA tend to be much greater than in Europe or Japan. Even if you had high speed rail it’d still take a very long time to cross the continent! High speed trains do exist, or are being built, in more densely populated US regions (eg Northeast corridor, California).
        nickjj 8y ago
        It takes around 4-5 days to cross the US by train. 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.
        lhopki01 8y ago
        The distances between cities in California or the upper East coast isn't. Both places have a high enough population density to support a good train network. 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.
  - Uberphallus 8y ago
    That's the exact same reason why nobody sane takes a train in France for anything that matters. Schedules violated every day, strikes, poor maintenance, and moreover, they killed almost all of the night trains, that were the cheapest option especially if you account for one night you save on accommodation.
- ggg9990 8y ago
  Yeah, in today's world, I can only imagine supersonic being of even any benefit on flights longer than 8 hours.
- cornholio 8y ago
  Agreed. I think self driving technology can help here. I imagine a lobby area where you check-in, go through passport and baggage control, then board a pod that securely takes you right on the tarmac, to the mobile ladder adjacent to your half of the plane. 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.
  - rimliu 8y ago
    > The whole duty free forced march -> endless tread mills > -> gate -> bus routine is harrowing busy work. Is it not a purpose of it, at least in theory the opposite, to distribute flow os passengers in space and in time? 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.
    - cornholio 8y ago
      I disagree that the spatial layout of an airport is, even theoretically, designed to distribute the flow of passengers in time - otherwise, it wouldn't involve multiple queue/sync points, some involving all passengers of a flight. 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.suffix.html/article/travel/terminal-transfer/terminal-transfer-via-skyline.html https://www.frankfurt-airport.com/en/travel/transfer.detail.... [2] https://en.wikipedia.org/wiki/ULTra_(rapid_transit) https://en.wikipedia.org/wiki/ULTra_(rapid_transit)
- janlaureys 8y ago
  Airports make a fair share of their money by passengers hanging around and spending money in shops and restaurants. This video is pretty interesting: https://www.youtube.com/watch?v=wdU1WTBJMl0 https://www.youtube.com/watch?v=wdU1WTBJMl0
- bauc 8y ago
  Some airports make a significant portion of the revenue from the long wait between security and take off (e.g. Heathrow where they only show departure information 45 mins before leaving and you are surrounded by shops).
- Gravityloss 8y ago
  Just the normal airport designs could be improved a lot, with no added technology. It doesn't take a genius to see how many airports have very long walking distances or oddly placed stairs etc. 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.
- cloudblockchain 8y ago
  Ban Muslims Alright ban me but we all know this is the truth. 2.8T USD and so much productivity has been lost since 9/11. Anyway I'm going to get banned but I hope this username can be recycled and my sacrifice shall not be in vain.
- AndrewDucker 8y ago
  It's the uncertainty that leads to longest wait times. 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.
- dsr_ 8y ago
  The good news is most of the changes you want are political rather than technological. There's no law of physics or even of economics that prevents us from having airports where, once you have a ticket, you hand your luggage to a machine then stroll over to your departure gate and board the plane as soon as it is ready. The bad news is that political changes need the cooperation of large groups of your fellow citizens.
crazy_monkey 8y ago
Kill everyone's eardrums and then you wont need to kill the boom...
ckocagil 8y ago
This reminds me of a Wendover video I've seen. The author discovers that airplanes used to fly much faster in the 1960s than they do today. So our flight times have actually gone up! He then explains the reasons behind it. https://www.youtube.com/watch?v=n1QEj09Pe6k https://www.youtube.com/watch?v=n1QEj09Pe6k
- caio1982 8y ago
  There is also another Wendover one explaining the economics or airlines classes and it talks about specifically why supersonic flights went into oblivion: https://www.youtube.com/watch?v=BzB5xtGGsTc https://www.youtube.com/watch?v=BzB5xtGGsTc
baybal2 8y ago
>Is killing the boom the key to supersonic air travel? No. Cost is
- geertj 8y ago
  To get to low cost you need a lot of routes to fly on. Without a sonic boom can fly over land which opens up more routes. Therefore, the lack of a sonic boom does contribute to the comeback of supersonic air travel.
  - baybal2 8y ago
    Sonic boom is a joke of a criterion. US is surely a big market, but nowhere as important as it was 40 years ago. US will have a choice: to deny SSTs when the rest of the world flies them, or do not do so. 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.
    - jrockway 8y ago
      Which countries contain residents that are happy to have their windows broken by sonic booms several times a day? If one exists, then yes, they will be ahead of the curve on SST.
    - ghaff 8y ago
      I have no reason to think that the US would uniquely ban the use of technology that Western Europe was fine with. (Though one can certainly imagine e.g. China allowing for noise levels that the US and other countries wouldn't be OK with.) 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.
      - baybal2 8y ago
Theodores 8y ago
I suspect that the solution to the problem may look very different to the planes and drawings of planes shown in the article. 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.
- NLips 8y ago
  The key point you're missing is that subsonic and supersonic flows are very different - in terms of fluid dynamics, supersonic planes are not just faster than subsonic planes. Commercial jets and F1 cars are optimised for subsonic flows. To handle supersonic flight, you need to do things which are strange and suboptimal for subsonic travel. This is partly why subsonic planes don't look like concorde. 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.
  - 8y ago
slivym 8y ago
I'd really like to see proper numbers on the fuel economy of these proposed solutions. Because whilst it's nice to throw your hands in the air and say 'Ah well it'll be like first class' - there are many problems with that. 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.
- Reason077 8y ago
  ”Boom Supersonic are planning a 55 passenger plane. That is laughable as a commercial proposition.” 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.
  - sokoloff 8y ago
    My experience with private aviation suggests that getting somewhere exactly when they want, flying into airports closer to their destination, stepping directly out of/into ground transportation and, to a lesser extent, having privacy en route are significant drivers for the private aviation crowd. 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.
    - 8y ago
phyzome 8y ago
The title is a bit silly -- sonic booms weren't what killed the Concorde, it was cost -- but I'm glad to see the article goes into the need for fixing both problems.
- mannykannot 8y ago
  True, though the inability to do transcontinental flights exacerbated this by effectively eliminating any hope of recovering development costs or achieving any other economies of scale. 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.
kazinator 8y ago
Nope, killing Amdahl's Law is the key to supersonic air travel. 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.
- mmt 8y ago
  > 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.
syntaxing 8y ago
I think the only way to kill the boom is to change the aerodynamics of the plane at different flying conditions. The only way to do this is to change what the air "sees" when it hits the planes wing surfaces by changing the turbulent and laminar regions. Unfortunately most methods are not quite there yet.

53 points by bauc 8y ago

I would like to see supersonic travel come back. 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.

struppi 8y ago
This is exactly the reason why I usually prefer a 6-hour train ride to a 1-hour flight (at least in Germany, Austria, Switzerland). 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.
- toothbrush 8y ago
  So much this. Not to mention the reduced environmental impact. Flying is absolutely catastrophic in terms of greenhouse gas emissions, and the Paris accord doesn't cover even a fraction of it! (because flying occurs in "international space" and so it doesn't appear on any country's "balance sheet"... atrocious.)
  - audunw 8y ago
    > Flying is absolutely catastrophic in terms of greenhouse gas emissions 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.
    - llukas 8y ago
      Is it still competetive vs car for supersonic flight?
    - cornholio 8y ago
      I know Boeing proposed Methane turbofans, and they were estimated to have 60% less carbon emissions and cheaper than jet fuel - after eating the large development and infrastructure costs. You could take this even further, producing Hydrogen from clean electric energy is about three times more expensive than methane for the same energy content, leading to a moderate increase in the cost of even a low cost ticket. 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.
      - erezyehuda 8y ago
        Costs aside, wouldn't replacing carbon emissions with methane be drastically worse? Doing a casual search says that methane is 2000-3000% more potent as a GHG.
        ufo 8y ago
        I assume the methane would be the fuel, not the byproduct.
  - mehrdadn 8y ago
    I'll point out that although it's indeed atrocious compared to a train ride, flying is still more efficient than driving a car. So if traveling is required and you're debating between driving vs. flying (say SF <-> LA), you should prefer flying unless you can carpool. I don't know the exact numbers since it depends on where you're going and what plane/airline you fly, but I would expect around 50-75 MPG for a reasonably full airplane [1], whereas your car might be more like 25-30 MPG on the highway, so you'd want at least 2-3 (ideally 4) people in the car to make it more efficient. 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#Airlines https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft#Airli...
    - Reason077 8y ago
      That’s true today. But in the coming years and decades, ground transport will be largely electrified and it’s per-mile emissions greatly reduced. 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.
      - mehrdadn 8y ago
        With battery capacities being what they are you'll also have to hang tight for the moment when they stretch long enough to allow you to even have the choice of driving to the same place you can fly. (Or swap batteries on the way somehow... not sure how well that would work.)
        Reason077 8y ago
        This is already solved in technology terms. Battery capacities and charging speeds are already good enough for almost all long-distance travel scenarios. It’s now just a case of getting costs down and infrastructure built out. But that’s the easy part.
- kiba 8y ago
  All these security for air travel but not for a train which is also full of lot of people felt bizarre.
  - dijit 8y ago
    You can't hijack a train and take hostages to some other country; This was endemic in the 80s. You also can't hijack a train and drive it into a building.
    - amelius 8y ago
      But is this still true for airplanes, given the switch to hardened cockpit doors?
      - Uberphallus 8y ago
        Then you get Germanwings incidents
        amelius 8y ago
        Which can't happen on trains and buses?
        endymi0n 8y ago
        Buses, maybe. Trains: Nope. Doors are locked from the inside, usually aren't accessible while moving and even someone would get inside, well, you can't get off the tracks. You'll get a red signal and a forced braking shortly afterwards. It's really, REALLY hard (by design) to wreck something on purpose with a modern high speed train.
        Uberphallus 8y ago
        And in buses you can't really lock yourself out as a driver.
        8y ago
- Numberwang 8y ago
  I'm totally with you, but it is truly annoying the amount of subsidies the flight industry get. I've often taken trains across Europe due to my preference, but when the plane ticket is €20 and the train ticket is €400 it seems I'm fighting against the system.
  - peteretep 8y ago
    > but it is truly annoying the amount of subsidies the flight industry get Please could you illustrate some of those for me, as compared to rail?
    - yrro 8y ago
      UK here. > 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. https://www.aef.org.uk/issues/economics/taxation/ https://www.aef.org.uk/issues/economics/taxation/
    - Reason077 8y ago
      1. International airlines pay no tax on aviation fuel, despite their significant contribution to air pollution and climate change. In say, Europe, this represents a huge subsidy compared to ground transport, where fuel is heavily taxed. 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!
- Swizec 8y ago
  I traveled with the French TGV a couple times and it is absolutely astounding how amazing it is. Large comfy chairs, quiet train, you can walk around, plenty of room for activities. There's even a bar where you can hang out with fellow passengers! 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.
  - maeln 8y ago
    Although I like our (maybe not for long) nationalized train system, I still have to mitigate your praises a bit :) . 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.
- garmaine 8y ago
  Lol, try living in California. 6-12 hour plane ride to anywhere. Trains? We have them. But why would you when it takes literally days to cross the country.
  - dewey 8y ago
    That's not a problem of trains it's a problem of the US train infrastructure. As you can see in Europe or Japan trains can be very fast and very efficient.
    - Reason077 8y ago
      Sure, but the distances between cities in a huge country like the USA tend to be much greater than in Europe or Japan. Even if you had high speed rail it’d still take a very long time to cross the continent! High speed trains do exist, or are being built, in more densely populated US regions (eg Northeast corridor, California).
      - nickjj 8y ago
        It takes around 4-5 days to cross the US by train. 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.
      - lhopki01 8y ago
        The distances between cities in California or the upper East coast isn't. Both places have a high enough population density to support a good train network. 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.
- Uberphallus 8y ago
  That's the exact same reason why nobody sane takes a train in France for anything that matters. Schedules violated every day, strikes, poor maintenance, and moreover, they killed almost all of the night trains, that were the cheapest option especially if you account for one night you save on accommodation.
ggg9990 8y ago
Yeah, in today's world, I can only imagine supersonic being of even any benefit on flights longer than 8 hours.
cornholio 8y ago
Agreed. I think self driving technology can help here. I imagine a lobby area where you check-in, go through passport and baggage control, then board a pod that securely takes you right on the tarmac, to the mobile ladder adjacent to your half of the plane. 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.
- rimliu 8y ago
  > The whole duty free forced march -> endless tread mills > -> gate -> bus routine is harrowing busy work. Is it not a purpose of it, at least in theory the opposite, to distribute flow os passengers in space and in time? 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.
  - cornholio 8y ago
    I disagree that the spatial layout of an airport is, even theoretically, designed to distribute the flow of passengers in time - otherwise, it wouldn't involve multiple queue/sync points, some involving all passengers of a flight. 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.suffix.html/article/travel/terminal-transfer/terminal-transfer-via-skyline.html https://www.frankfurt-airport.com/en/travel/transfer.detail.... [2] https://en.wikipedia.org/wiki/ULTra_(rapid_transit) https://en.wikipedia.org/wiki/ULTra_(rapid_transit)
janlaureys 8y ago
Airports make a fair share of their money by passengers hanging around and spending money in shops and restaurants. This video is pretty interesting: https://www.youtube.com/watch?v=wdU1WTBJMl0 https://www.youtube.com/watch?v=wdU1WTBJMl0
bauc 8y ago
Some airports make a significant portion of the revenue from the long wait between security and take off (e.g. Heathrow where they only show departure information 45 mins before leaving and you are surrounded by shops).
Gravityloss 8y ago
Just the normal airport designs could be improved a lot, with no added technology. It doesn't take a genius to see how many airports have very long walking distances or oddly placed stairs etc. 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.
cloudblockchain 8y ago
Ban Muslims Alright ban me but we all know this is the truth. 2.8T USD and so much productivity has been lost since 9/11. Anyway I'm going to get banned but I hope this username can be recycled and my sacrifice shall not be in vain.
AndrewDucker 8y ago
It's the uncertainty that leads to longest wait times. 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.
dsr_ 8y ago
The good news is most of the changes you want are political rather than technological. There's no law of physics or even of economics that prevents us from having airports where, once you have a ticket, you hand your luggage to a machine then stroll over to your departure gate and board the plane as soon as it is ready. The bad news is that political changes need the cooperation of large groups of your fellow citizens.

crazy_monkey 8y ago

Kill everyone's eardrums and then you wont need to kill the boom...

ckocagil 8y ago

This reminds me of a Wendover video I've seen. The author discovers that airplanes used to fly much faster in the 1960s than they do today. So our flight times have actually gone up! He then explains the reasons behind it. https://www.youtube.com/watch?v=n1QEj09Pe6k https://www.youtube.com/watch?v=n1QEj09Pe6k

caio1982 8y ago
There is also another Wendover one explaining the economics or airlines classes and it talks about specifically why supersonic flights went into oblivion: https://www.youtube.com/watch?v=BzB5xtGGsTc https://www.youtube.com/watch?v=BzB5xtGGsTc

baybal2 8y ago

>Is killing the boom the key to supersonic air travel? No. Cost is

geertj 8y ago
To get to low cost you need a lot of routes to fly on. Without a sonic boom can fly over land which opens up more routes. Therefore, the lack of a sonic boom does contribute to the comeback of supersonic air travel.
- baybal2 8y ago
  Sonic boom is a joke of a criterion. US is surely a big market, but nowhere as important as it was 40 years ago. US will have a choice: to deny SSTs when the rest of the world flies them, or do not do so. 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.
  - jrockway 8y ago
    Which countries contain residents that are happy to have their windows broken by sonic booms several times a day? If one exists, then yes, they will be ahead of the curve on SST.
  - ghaff 8y ago
    I have no reason to think that the US would uniquely ban the use of technology that Western Europe was fine with. (Though one can certainly imagine e.g. China allowing for noise levels that the US and other countries wouldn't be OK with.) 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.
    - baybal2 8y ago

Theodores 8y ago

I suspect that the solution to the problem may look very different to the planes and drawings of planes shown in the article. 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.

NLips 8y ago
The key point you're missing is that subsonic and supersonic flows are very different - in terms of fluid dynamics, supersonic planes are not just faster than subsonic planes. Commercial jets and F1 cars are optimised for subsonic flows. To handle supersonic flight, you need to do things which are strange and suboptimal for subsonic travel. This is partly why subsonic planes don't look like concorde. 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.
- 8y ago

slivym 8y ago

I'd really like to see proper numbers on the fuel economy of these proposed solutions. Because whilst it's nice to throw your hands in the air and say 'Ah well it'll be like first class' - there are many problems with that. 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.

Reason077 8y ago
”Boom Supersonic are planning a 55 passenger plane. That is laughable as a commercial proposition.” 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.
- sokoloff 8y ago
  My experience with private aviation suggests that getting somewhere exactly when they want, flying into airports closer to their destination, stepping directly out of/into ground transportation and, to a lesser extent, having privacy en route are significant drivers for the private aviation crowd. 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.
  - 8y ago

phyzome 8y ago

The title is a bit silly -- sonic booms weren't what killed the Concorde, it was cost -- but I'm glad to see the article goes into the need for fixing both problems.

mannykannot 8y ago
True, though the inability to do transcontinental flights exacerbated this by effectively eliminating any hope of recovering development costs or achieving any other economies of scale. 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.

kazinator 8y ago

Nope, killing Amdahl's Law is the key to supersonic air travel. 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.

mmt 8y ago
> 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.

syntaxing 8y ago

I think the only way to kill the boom is to change the aerodynamics of the plane at different flying conditions. The only way to do this is to change what the air "sees" when it hits the planes wing surfaces by changing the turbulent and laminar regions. Unfortunately most methods are not quite there yet.