Why air travel hasn't gotten any faster since the 1960s

https://alum.mit.edu/pages/sliceofmit/2014/03/19/airtravel/

by nmorell • 12 years ago

27 75 12 years ago

alum.mit.edu

onuryavuz• 12 years ago

So if the main issue is fuel economy, then we can assume that the future of air travel is an electric aircraft. I think weight is a major issue in electric aircraft design, how many batteries does it take to get an airplane off the ground ?

bluedevil2k• 12 years ago

Electric cars and batteries are by no means my area of expertise, but I'd have to believe that the size and weight of the batteries needed for an electric plane would be totally unfeasible for efficient flight. Just for a comparison, a Tesla Model S weighs 4600 pounds, while a BMW 5 series weighs 3900 pounds, so the Tesla is about 20% heavier.

Plus, Jet A (kerosene) is relatively cheap compared to the cost of electricity and batteries.

Finally...imagine the range anxiety of a battery powered 777.

pageld• 12 years ago

The range anxiety is based on not being able to fill up anywhere (electrically) even through there is plenty of alternative energy (gas) at every exit. There aren't any jet fuel stations in the sky, so planes already have this problem.

I don't think we'll see electric planes anytime soon since I see the future being a mix of all types of energy, but range anxiety isn't the problem.

Turing_Machine• 12 years ago

Some ideas I've seen involve microwave power beamed down from space and/or up from ground stations. No batteries.

jerf3• 12 years ago

You're better off using nuclear power or renewable energy to create carbon-neutral jet fuel than anything else. I doubt there's any other way to fly than hydrocarbons (or equivalent chemical energy). Nuclear planes are also a joke (I believe they are theoretically physically possible, but have to be huge, and of course there's the little issue of flying nuclear reactors around in the sky), all the other alternate energies are right out, and none of the non-rocket alternate thrust methods have anywhere near enough specific impulse to get a plane off the ground, to say nothing of the unpleasantness of something like ion drives taking off in the middle of populated metropolises all the time. (Any ion drive that could drive a plane would sterilize quite a bit of landscape in the process.) Rockets might theoretically work but obvious jet engines win out in practice in this use case.

Tloewald6• 12 years ago

When the Hyperloop stuff first being hinted at, I assumed the trick was electrically accelerating gliders in a series of hops (avoid the biggest cost of rail -- the rails).

The fact is that energy efficiency is never not going to be a factor and air travel is actually plenty fast for most purposes. The big problem is cost and external friction (getting to/from the airport, on/off the airplane).

It's like saying "phone calls haven't gotten any better in the last 50 years" -- except for cost, convenience, ease of getting a connection (e.g. you used to need to book international calls and get an operator to connect long distance calls).

JoeAltmaier4• 12 years ago

How is that like air travel? "convenience, ease of getting a connection" for instance - we've screwed that up at airports for a decade now (since 2001 of course).

Not plenty fast for most purposes. Takes a day of pain to get anywhere. Used to be, you could go and get back same day. That's a huge setback.

ohadron• 12 years ago

Neglecting the weight of the engine / motor itself, the energy density of jet fuel is about 46 MJ/kg, and with batteries you can only get to about 1.5MJ/kg. Mobile phone batteries are about 0.5MJ/kg.

So thats at least 30 times more weight than is required with jet fuel.

Electricity is probably not it.

mfenniak• 12 years ago

It's actually worse than this when you consider that aircraft become more fuel efficient the longer they fly, because they're not carrying around the fuel they've already burnt. An electric aircraft would presumably have a constant weight (stuff + batteries).

nknighthb2• 12 years ago

Absent a breakthrough in battery technology, EV-like airliners are unlikely, and in any event would not be a complete fix for "fuel economy" problems -- it isn't just about the simple cost of fuel, but also about range, size/weight/materials, and the number of passengers (and degree of comfort).

mikestew• 12 years ago

I think the major issue is turnaround time. It takes 7 hours to recharge my Leaf. How long would it take to charge a 777? Yes, "but swappable batteries!" And how long does it take to swap batteries including the inspection and paperwork that I'm sure must be required when swapping out a major component in a commercial passenger aircraft?

chrisBob4• 12 years ago

Air travel has gotten MUCH slower in the last 20 years. I need to show up at Logan about 2 hours before takeoff for a 90 minute flight to DC. The terrorists slowed flights down much more than fuel economy on all but the longest flights.

Tloewald6• 12 years ago

In the 60s and 70s every bag was searched by hand in front of you on international flights. We're actually no worse off than those days.

In the late 90s you could roll up to the airport 15 minutes before an international flight, walk to the plane hardly breaking stride for customs, fly to your destination, and walk out to the taxies -- again hardly breaking stride for customs.

Then there was 9/11.

qwerty_asdf• 12 years ago

...which, of course, involved no international flights.

nknighthb2• 12 years ago

You don't go through customs at all for an outbound flight. If you're a non-citizen/permanent resident, you just get an immigration officer to stamp your passport.

If you're leaving the US, things probably aren't much more involved at the destination. It's when you come back that you have to deal with pissy immigration and customs officers.

ochiba• 12 years ago

Didn't universal bag searches only start in 1973 in the aftermath of D.B. Cooper and all his copycats?

http://en.wikipedia.org/wiki/D._B._Cooper#Airport_security

flexie• 12 years ago

Absolutely. The gains that could be achieved by flying even twice as fast isn't much compared to the time we could save if we could get to, from and through airports the same way that we move around subway systems: by carrying our own luggage, no check-in, no registration, no reservations, no security, no forced shopping malls, waiting 10 minutes for connections, not several hours.

A 2 hour flight, e.g. from NYC to CHI, is often 6-8 hours with all the surrounding nonsense. Getting from Manhattan to JFK, Newark or even LaGuardia is easily 1-2 hours, waiting in the airport, going through security etc. is another 1-2 hours. Getting through the destination airport from the moment the plane touches down and until you are actually leaving the airport with your luggage is rarely less than an hour. And then the transport into the city is another hour.

With transatlantic flights it's often 14-15 hours or even easily 20 hours if you need a connecting flight in one end, although the connecting flight is "just a one hour flight", because of all the waiting between flights.

Flying is great. Everything around it is terrible.

jmspring2• 12 years ago

There are ways you can make many parts of the US experience better -- PreCheck, Clear, etc. if they are available at the airports you travel through. This has saved me a LOT of time at SFO and SJC.

For international flights returning to the US, at this point Global Entry is almost a must. Last return flight MUC -> SFO, if we didn't have Global Entry, we would have been in line for at least an hour. GE kiosk? A couple of minutes including needing to type in my flight details.

As PreCheck becomes more popular, I suspect some parts of flying will become a bit smoother for people overall.

JoeAltmaier4• 12 years ago

All to do with cost. Fuel indirectly - going faster for shorter hops requires flying lower, with geometrically increasing air resistance and thus fuel expenditure. Going higher takes time on takeoff and landing, and requires pressurized cabin, oxygen etc. Making the plane heavier and costing fuel again.

So we're at a carefully calculated sweet spot. Until physics changes, we'll stay here.

PeterisP• 12 years ago

It's important to note what are the long-awaited features in recently released aircraft models and the models currently in development - pretty much the only thing the're advertising is various factors that decrease fuel consumption - lighter weight by advanced materials, more efficient engines, etc.

blackaspen3• 12 years ago

This article states the obvious.

I'm a little upset that there is no mention about fuel economy per passenger mile as that's where the numbers get interesting.

Concorde got 14 passenger miles per gallon, a 747 gets 91 (http://en.wikipedia.org/wiki/Fuel_economy_in_aircraft). That's why planes are slower. I'd imagine that a 787 is north of 100(probably 120ish) passenger miles per gallon, but it too is slower than a 747.

Now, with current technology, we could build a plane that is as economical as a 747 and much faster -- this would be the Boeing Sonic Cruiser, but cost still wins.

As far as the whole 2-hours-before-the-airport nonsense, I don't buy that that's an issue. I haven't shown up at an airport more than an hour before my flight time in a long time (and have yet to miss a flight). I walk right onto the plane.

The bigger problem with travel speed is the last mile. It may take me two hours to go from Denver to San Francisco, which is 967 miles, but it takes me an hour to get from SFO to Palo Alto on public transit at the least -- in the same time I could already be in LA.

lostlogin• 12 years ago

Have you tried entering or leaving the US when only showing up an hour before? I'd like someone else to try that and let me know how it goes. With international travel, it isn't the last mile that's the problem IMHO. It is security checks and customs and it is awful.

saryant4• 12 years ago

The US doesn't have exit immigration or customs, departing the country is the same procedure (airport-wise) as taking a domestic flight. Same security and often the same terminal.

I rarely show up an hour before a flight (including international) and I've yet to have an issue. Even United says that an hour is sufficient for international flights, even less if you aren't checking bags and can print your boarding pass at home:

http://www.united.com/web/en-US/content/travel/airport/proce...

blackaspen3• 12 years ago

Yes, many times. In the US it's no problem, there are no exit immigrations.

The only time I've been nervous about catching an international flight was from HKG->SFO when there was a small line for exit customs. I showed up to the airport about 45 minutes before my flight and their lack of TSA-esque security made up for waiting to get my passport checked. I got to the gate just as they started boarding my group.

chrisBob4• 12 years ago

I guess it depends on the airport. Boston is one of the worst I have seen. When I fly through Raleigh/Durham it is magical how much better it is.

eob• 12 years ago

Which terminal do you usually fly out of?

I'm nearly always flying out of C (United/JetBlue) and my experiences in Boston have usually been the opposite: thankful at what a convenient airport we have here compared to the other city in my trip [1] -- including Raleigh (though the rocking chairs are a nice touch!).

I never considered it before, but maybe Logan's terminals vary greatly in their convenience.

[1] Assuming the other city is in the US, since international airports are usually more pain-free than US ones as a general rule.

k-mcgrady4• 12 years ago

I don't really care about going any faster. 8 hours to get from Europe to North America is fine with me. The problem I find flying is comfort. Since the 60's it's got a lot worse. It seems every year they cram the seats closer together and make the entire experience worse. As a tall - but not that tall - person (6ft1") flying can literally be painful if I don't get an isle seat. Obviously the issue is people want to fly cheaply. A good solution might be to introduce a new 'mid-tier' class between economy and business. I would happily pay an extra 10-20% for an extra bit of space.

vvvv• 12 years ago

That's premium economy, although actual value for extra money depends on an airline. In fact, the whole experience depends massively on the airline of your choice, with US airlines, in my opinion, being well towards the bottom of the pile.

aidos• 12 years ago

And presumably they wouldn't need to charge anything like that to make it more comfortable, even taking out a few rows would make a big difference.

Having done a couple of 12 hour stretches while holding a small child in my lap, I'd definitely agree with you on making it more comfortable :)

JoeAltmaier4• 12 years ago

This gets tried every couple of years. Trouble is, almost everybody buys the cheapest ticket. ANd taking rows out cuts directly into the bottom line -6 or 12 fewer passengers cuts profit instantly. So it never lasts. You can't fill up a plane this way, and that's the only thing that matters.

rwissmann• 12 years ago

Good point. Airlines seem to have caught on to this with ideas such as extra legroom and premium economy seats.

Breefield• 12 years ago

Exit rows usually offer this for $50.

ronaldx2• 12 years ago

Going faster would mean less time sat in discomfort.

It's OK (for me) to sit in the cheapest seats of a plane for 2-3 hours, but for 6-8 hours is very tough.

k-mcgrady4• 12 years ago

I guess it depends how far you're flying and how much quicker they could make it. 2 hours is my limit before the discomfort starts to get irritating. Usually by the last 2-3 hours of an 8 hour flight I'm counting down the seconds until I can get off.

arethuza• 12 years ago

British Airways World Traveller Plus is pretty good - much better than BA economy and without the silly cost of real business class:

http://www.britishairways.com/en-gb/information/travel-class...

[Edit: I did a check on a random flight from LHR <-> SFO and Premium economy was about twice economy and about half of business.]

k-mcgrady4• 12 years ago

Thanks that's the sort of thing I'm looking for although I'd rather they reduced the price slightly and just offered the extra leg room. I don't really care about nicer meals or attentive service.

wicknicks• 12 years ago

The problem is not to to just get from point A to B, but to have a good experience doing it. Air travel is getting worse every year. Starting from the airport checks to the long immigration lines (when traveling internationally) and super expensive fares for those "cuddly" seats, it can make holidays more exhausting than work. And if you live an hour from the airport, well good luck!

My idea of a grand future is when we can travel across the globe in less than hour, and pay less than $50 doing it.

blackaspen3• 12 years ago

I'll take the faster jet and be enjoying a drink in London before you even get your first "meal service".

If you only care about comfort, why don't you take a boat? A transoceanic trip for about $3k will get you an inside room and take ~12 days.

vehementi2• 12 years ago

Are you sure you're replying to the right thread / post? Nobody said anything about only caring about comfort.

AndrewKemendo• 12 years ago

Well that is what First Class is for. Oh you wanted it to be the same price?

It has only gotten worse since the 60's because now YOU and I can afford to fly. Back in the "golden age" people flew maybe once a year and saved in order to do so. Even then it was mostly well to do people flying - now it may as well be the bus. The relative price per ticket now compared to the 60's is nickles.

I flew on spirit airlines a few months ago round trip from DCA to DFW for $128. That's INSANE low. In 1960 dollars that would have been ~$16. You weren't flying anywhere for $16 in the 1960s.

People wanted to fly, so the airlines accommodated that by smashing us together and giving us low fares - making themselves not really that rich in the process.

k-mcgrady4• 12 years ago

> "Well that is what First Class is for. Oh you wanted it to be the same price?"

First class is hugely more expensive than economy. I'm proposing a new middle tier.

I just did a search for a Belfast > New York flight next month.

Economy: £532

Business: £2,636

First class: £6,809

If they added a section with increased space for passengers (no champagne or other extras) and charged £800-1000 for it I'd pay and I'm not someone with money to throw around - that's how uncomfortable I find flying. All I'm asking for is an extra couple feet spacing between seats.

Al-Khwarizmi• 12 years ago

I am 1.96 m tall (6'5") and I would also pay 10-20% more for some leg room when I pay for the tickets myself. But when I fly for work purposes (i.e. the vast majority of the time), this is not an option, regulations say I can only fly in economy class. I suppose many people is in the same situation.

I don't really think having enough space to actually fit in the seat should be considered a premium. It should be a right.

bane• 12 years ago

I fly to Europe and Asia at least once a year, and somewhere within North America at least once a year. I've flown both coach and business class on all of these.

Consistently, the US<->Asia flights are incomparably better. If I could pay a little more and get a Korean Air flight to Paris, I'd do it. Coach on various Asian airlines is about as good as some European and North American airline's business class. Seat comfort, level of service, aircraft cleanliness, etc.

I'll add that my back is ready to go out on even a D.C. to Denver leg on United, and I've almost never flown domestically and not gotten some kind of upper respiratory infection as a final parting gift. Air France, Lufthansa, KLM, British Air, United International to Europe is a similar experience, just longer and more horrible.

U.S. East Coast to Seoul nonstop is one of the longest routes in current commercial service, and I've hopped off the plane refreshed and ready to go do things every time. The standard kit in coach even includes an eyemask to help you sleep and the flight attendants bring around hot towels every so often so you can wipe down your hands and face. Bathrooms are well stocked with toothbrushes and toothpaste and getting water or snacks outside of regular meal time has never been a problem. On some flights they'll even give you cans of spray water to spritz on your face to cool off and refresh yourself. Food is consistently "decent". And paradoxically, seats are wider, better cushioned and more comfortable than the business class seats I've flown on to Europe on flights half as long.

I wish there was some way to bring this level of service to Western airlines, but to be honest, I count a domestic flight on United a success if all the lavatories are in service and don't overflow into the aisle.

jmspring2• 12 years ago

Surprisingly, my last SFO -> Europe flight, the United plane was more comfortable than the Lufthansa return (Economy Plus, vs. plain Economy for LH -- but LH seats are very austere/lack padding it seems).

larsberg• 12 years ago

A good solution might be to introduce a new 'mid-tier' class between economy and business. I would happily pay an extra 10-20% for an extra bit of space.

United's Economy Plus is huge for me for this reason. An extra 3-6" of legroom (depends on the plane and the flight leg) makes a big difference at that height. It doesn't help at all with seat width though, unfortunately.

true_religion• 12 years ago

Faster is a big deal for me. Most of my flights are US -> Asia or US -> Africa. Going to Africa is a 25hr + flight due to the need to segue through Europe. Going back is worse since the segue is usually through the Middle East.

Going to Asia is a painful crossing over the Pacific with a brief stopover in Hawaii to make it at least 18hrs.

alphaBetaGamma• 12 years ago

I can't seem to be access the article, and so don't know if it focuses on waiting at the airport or the air speed of planes. Regarding the latter, for physics minded people, I recommend David McKay chapter on air travel[1] in his book "Without the hot air" -- actually I recommend reading the whole book, it's free.

You need to spend energy to counterbalance the drag on the airplane (which grows as speed^3) and to providing lift (which grows as 1/speed), so there is an optimal speed (if you are optimizing fuel efficiency). So you don't expect to see major increases in speed unless you are ready to burn much more fuel.

[1] http://www.withouthotair.com/cC/page_269.shtml

chrisBob4• 12 years ago

The article is about air speed and explaining it with fuel efficiency. I don't think a 10% bump in cruising speed matters all that much in the total door to door time though.

zacinbusiness• 12 years ago

My wife and I frequently travel to London (we go each summer, and in fact are in the process of planning this year's adventure today because we've bought tickets to the Monty Python show at the 02!).

The first time I got on an international flight I was actually surprised that it wasn't more uncomfortable. There was some space for my elbows and I could comfortably use my iPad. That was for the first 4 hours. After that I was extremely uncomfortable and unable to sleep and I felt like I had been kicked in the face by the time we finally landed at LHR.

I'm a pragmatist, however, and so I don't complain too much about the cost (1300 or so each for a round trip isn't really all that bad). And I also understand that more comfortable seats take more space and use more material, which increases weight and thus cost. And at the same time, spending less time in the air means going faster, increasing speed and also cost.

Thus, it seems to me that the advancements need to come in the areas of materials (lighter, stronger build materials for the amenities) and in aerodynamics (which I'm sure are limited by safety requirements and the problem of getting that many people across the pond at one time).

Why air travel hasn't gotten any faster since the 1960s

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