If anything we should look at the trade-off benefits of flying with the least amount of fuel consumption per passenger and miles flown. Flying faster than mach-1 to save time will be reserved to a small elite. How does it benefit the masses?
If anything we should look at the trade-off benefits of flying with the least amount of fuel consumption per passenger and miles flown. Flying faster than mach-1 to save time will be reserved to a small elite. How does it benefit the masses?
A lot of the assumptions people make about efficiency don’t hold water in aerospace. There are no laws of physics preventing supersonic aircraft from being efficient provided they can fly high enough and we figure out how to build better engines.
If we really want time savings, fix the entire airport experience. Thats where time can be most saved. When travelling domestic I ussually end up spending far more time waiting for flights/bags/security than actually flying.
I remember the times before September 11, 2001, when I could show up at the airport about 30 minutes before my flight, get through security (which was locally operated -- no TSA), get my boarding pass at the gate, and board. It was great!
People could also meet you at the gate when you arrived, instead of outside the security area. There would always be peoples' families and loved ones there waiting for them.
If you are flying within Europe, without checking a bag, and have the QR code from your boarding pass, it always takes less than 30 minutes to get to the gate. Allowing an hour is more than safe.
The airport experience is why, even though I enjoy actually flying, I avoid doing it to the greatest degree I can. Everything that happens from the time I arrive at the airport to the time the airplane leaves the runway is awful.
The real difference now is that flying is too affordable. It used to be, only the rich could fly.
What we need to do is make air travel much, much more expensive, out of the reach of most people except on special occasions, and we can go back to having (1) less unnecessary carbon emissions from people flying to Disneyland or whatever shitty resort they spend their vacations at, and (2) very short waits at the airport for people who need to get somewhere in a hurry and can afford it.
Environmental and efficiency problem solved.
No, it assumes you care about reducing air travel more than equality of access to it
> forcing most people to become vegans because meat becomes too expensive
Sounds...effective? It isn't what is happening, but taxing the hell out of meat would be a great lever to pull if you want to drive consumption away from it.
Outside of cost the only possible lever is rationing. Good luck with that one.
wish that were true, but the variance of wait time, even with tsa precheck, etc defeats the purpose. needs to be reliably consistent (and short) for me to take advantage of a 30min show time.
Show up, hop on, tap your credit card to pay, and the plane takes off while you're still wandering down the aisle looking for a seat.
/fire suit on
From the bay area, there is nowhere you might want to go that a train would make less stressful.
Want to go to LA? That's 1 hour in the air for around 100 bucks. Or it's a 10 hour ordeal involving transfers between coach bus and train in more than one location. All for the low price of 60 dollars.
Want to go to New York? That's 6 hours by air or 80+ hours by rail. Where realistically you are going to book a roomette ($$$) and not just sit in coach for 3 days straight.
Hi! There are many of us who exist outside of the US and would be open to planes flying faster because the world is super big. Thanks for listening
Sure, but that isn’t particularly affected by restrictions on supersonic flight over the US.
(London-LA semi-frequent flyer).
https://www.greatcirclemapper.net/en/great-circle-mapper.htm...
Non-Americans who wish to complain about USA have a broad range of topics from which to choose; there's really no need to complain that USA regulates the operation of airlines in USA airspace.
Basically a faster airplane can have smaller wings which produce less lift and less drag. If we in spherical cow tradition ignore body drag, you can halve wing size, increase speed by 44% and have the same drag. You need more power but for a shorter duration, for the same energy usage per trip.
It's been a long time since I've touched compressible fluid mechanics or turbomachinery design, but if I recall correctly the theoretical "sweet spot" for overall aircraft efficiency is something like Mach 1.3. I'd have to dig though my textbooks to remind myself why, but the number stuck with me.
Can't find the picture anymore...
That wing lift/drag relationship may be less fungible than you're supposing in order to address lower-speed flight segments.
In reality, planes fly higher where the air is less dense, and faster to keep the lift and drag equal.
In a car, lift is not needed. Higher speed doesn't have compensating effects. Higher speed more clearly causes more fuel burn for the distance.
If anything, automobiles frequently utilise negative lift, as with a Formula 1 or Indy Car's inverted wing which generates increased downforces. On street cars you'll find spoilers and similar factors.
Aircraft can fly low and fast, though that's typically associated with combat aircraft evading radar or air-defence systems. Such missions are known as fuel-burners precisely because of the greatly increased drag.
But thank you for trying to point out that engineering efficiencies matter a great deal. Hopefully the message will get through.
This is true, but isn't the flip side of this that the high altitude emissions are much more damaging?
Efficiency for a given aircraft is nice but it's not the point. I believe Concord was most efficient at cruising speed (~Mach 2) but it does not change the fact that it burned like 4x more per seat/km than a b737 (Cf: https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft). Of course Concorde was only first class but that's part of the point of the parent.
As for boom, some guesstimate are around at least 4x too (https://theicct.org/new-supersonic-transport-aircraft-fuel-b...). No idea how biased this is but I believe it's quite telling that there is only mention of SAF on https://boomsupersonic.com/sustainability. At best in some 2017 article they compare themself to a lay-flat bed in subsonic business class, but since they only manage to secure an engine maker last year it was firmly in the guesstimate too.
As it stands, the economics of air travel force carriers to optimise for reducing fuel consumption, since that's (by far) the biggest fraction of a commercial aircraft's operating cost.
If supersonic transport makes a comeback, it'll be because the economics will make sense, which (in my mind) will be either because of:
- Somehow reduced fuel consumption, potentially through engines that leverage the effects of the supersonic flight regime for increased fuel efficiency (e.g. ramjets, through that likely wouldn't be possible in low-supersonic flight)
-> As another commenter in this thread mentioned, drag decreases with lower atmospheric pressure at higher altitudes, so there are fuel efficiency gains to be made just by flying higher, within the engines' design constraints.
- It'll fill the niche of richer-than-god people who use jets to skip highway traffic.
There's likely more cases than just these, but these are just the greatest hits as far as I can tell; and I say all of that as someone who's not involved in the aviation industry.
For the record, I don't support this second niche existing, but it does, and it can be an economic driver.
Not only this, but in general jet speeds have decreased due to airspace congestion. There is a lot of schedule padding due to delays at hubs like JFK, LAX, LHR, etc.
I am skeptical that lifting barriers to them polluting more would land any type of net benefit given that ultra-luxury products such as said jets don't tend to land outsized downstream advancements than let's say, funding basic sciences such as what Boeing or Airbus are already doing
(0) https://www.oxfam.org/en/press-releases/billionaire-emits-mi...
If it could be proved that things like faster private jets or faster planes could benefit in a sizeable and proportionate way to the general public, then yeah I would be in favor of this too, but as it stands I don't find the available info compelling, I'd rather them to pay more taxes
I like to bring up the question of how many startups and how much innovation is stifled because people stay with their jobs because of the healthcare.
Zoom is not a valid substitute when you’re trying to make high stakes decisions that involve millions - billions of dollars and complex relationships in multiple time zones. Saying that human progress depends on it is a bit dramatic but these folks allocate large amounts of capital and have an outsized impact on the economy.
Let's say that you can now make twice as many flights in a day. You can now do twice as many flights with the same crew and aircraft (same maintenance costs). Your fuel costs increase, but your other costs remain fixed, so despite the increase in fuel costs, you still end up making more profit. You might be able to charge more for the faster flights as well, and there may be beneficial second-order effects.
To skip highway traffic a richer-than-god person would use a helicopter. Private jets are used for further distances.
Nice language, was she stabbed? Has she lost money, job?
Why conflate well-deserved criticism with violence?
Being absurdly rich shouldn't give you license to destroy the planet.
It's not about saving humans from extinction.
It's just the smart thing to do unless we want to spend massive amounts of resources in the future to adapt to the consequences of a warming climate.
As trajectories go, currently habitable places will become uninhabitable within the lifetime of people you know. And that process isn't nice. Becoming uninhabitable means a series of natural disasters (and clean water pressures) that force people to migrate. Mass migration means global turmoil as people scramble to get safe. And many will die along the way. That's already started.
The planet will physically be here but its habitability matters too. I don't really care about what comes after humans, as long as it doesn't come now and kill me and mine.
If your only argument is "life, uhh, finds a way", that's great. Thank you for your contribution. Now find us a way to relocate a billion people in the next three decades.
The best combination of being technically correct of missing the point.
When peopme talk about the planet being destroyed, they usually mean for human life.
And not because it kills the planet less.
[cue sad trombone]
It's not perfect (as fossil fuels are still being burned) but it's better than nothing and a much more realistic solution than some extremist ideas such as stopping using fossil fuels overnight and effectively shutting down the economy as a result.
It's smarter to write regulation for each uniquely and directly.
Eg.
- Sound from air traffic shall meet <sound regulations> and when violated will incur automatic fees of <formula> amount.
- Air traffic emissions are required to meet <emission regulations> and will be taxed at <formula> amount (which should be used to offset pollution).
For emission, require airlines/airplanes to have a emission-sensor installed that automatically measure the emission. As a part of take off, make it mandatory to check it's working and as a part of landing, make sure it sent there data to where it has to go.
People love to blame SUV’s because they are in peoples faces, but replace every American SUV with an EV and the impact on the climate is negligible. Things would get just as bad a few weeks later, and that’s about it. People blame the rich and powerful because when you blame the people running things when things are fucked up.
Consider, the option for electrified roads instead of burning hydrocarbons existed 20 years ago. We could have reduced gasoline use by around 90% by now without any great breakthroughs but such choices aren’t up to individual consumers.
If you’re a middle-class American, you have a huge house by global standards, which you heat and cool more than just about anywhere else on Earth. Each family has two bigger than average cars which they drive more than most other countries. Middle class Americans also eat far more beef than most of the world.
It is true that middle class Americans fly less than the rich, let alone the super-rich in private jets.
Yes, the super-rich do pollute a great deal per capita. But the idea that American or indeed global emissions is in large part the result of private consumption of the super-rich is just wrong.
Climate change is beyond individual choices. The infrastructure of suburban homes and roads doesn’t go away when someone moves into a city.
The actual solution is to discourage and then eliminate mining coal and other fossil fuels. Rather than simply rearranging deck chairs on the titanic.
But then I see what happens at city council meetings and on local forums when people suggest loosening up on zoning rules to allow for denser development. It's mostly normal people that are pushing back on this stuff, and then blaming the "greedy developers" for trying to "ruin their neighborhood". That "traffic is bad enough" and that "our infrastructure can't handle it". We can't have separated bike lanes because "we don't have enough parking as it is", or "that road is already too full, we can't take away lanes". It's totally ingrained in our culture.
Who's been running the disinfo campaigns on carbon taxes?
It’s not like “oh the average Joe making 50k a year won’t be able to fly his supersonic jet because of the fines but rich people will”
No. Rich people, who fly business and first class still fly with the same airlines as poor people. The margins of the entire industry are thin.
I don’t think wanting fuel efficiency is incompatible with getting rid of the speed limit rule.
I'd make an example but these are exactly the sort of things that launch off topic 10 page discussions with very low information content.
Nevertheless, I think those are exceptions. I think first order effects tend to matter more than second order effects (that’s why they’re called first order) and not doing good first-order things because of potentially bad second-order things is often wrong.
Do you want waste? Because that's how you get waste!
More energy will cost more fossil fuels.
Whether it benefits the masses or the elite is irrelevant, what is relevant is that the use is worth more than the correctly priced cost of carbon
Why is that irrelevant? Must we permit everything that might be of benefit to someone, even if it comes at the expense of everyone else?
So EPA, FDA, etc regulations should be replaced with fees for poisoning everyone rather than outright bans, because to desire freedom from such concerns is to be a jealous tyrant?
The technically correct answer but practically silly answer is: yes because the correct charge for the externality of poisoning everyone would be asymptotic and unaffordable by anyone so it would amount to a ban.
Also the concern is not about being a jealous tyrant, the fact of the matter is markets almost always work better than dictating what to do, especially in the long term due to reacting to new information more effectively and changing course more effectively than an authoritarian regime.
Insofar as market based solutions I don't know why you imagine they should work. People are in general hideously stupid, immoral, incapable, greedy, and useless. The only way to make them behave with any modicum of sanity and decency is for someone educated in the topic of interest without a dog in the fight to stipulate based on objective standards the kind of things one must and must not due in order not to fuck their fellow man.
The fact that this at present remains less than ideal doesn't mean we ought to trust the same immoral pieces of garbage with less controls on the notion that they will do a better job that way rather than trivially corrupt the over-complicated process. By and large we know very well in most instances exactly what one should and shouldn't do we don't need a market based solution to figure it out we need a less bought and paid for government to actually implement what we already know.
Do we really have to rehash how and why markets work better in 2023? I mean, we spent the last century watching places that adopted freer markets succeed and places that went in the opposite direction failing, we saw communism fail a couple times, we watched communists that embraced markets turn themselves around (although they now look a lot more like facists, which is very concerning), etc. They likely work precisely because so much of humanity is hideously stupid, immoral, incapable, greedy, and useless and free markets allow those that aren't to supply the needs of the rest while building up capital, increasing influence and spreading capability throughout the system. On the other hand authoritarianism might have flashes of excellence but more often than not excellence has dumbass kids or friends that replace him or other factors change and the formerly excellent authoritarian doesn't pivot like the multitude of independent actors in a market can and then that flash is gone and we are back to stagnation for the society organized along authoritarian lines.
Your third paragraph's main flaw is that WE don't know very well in most instances exactly what one should and shouldn't do. YOU think you know that and YOU may be too hideously stupid, immoral, incapable, greedy and/or useless to know when YOU are wrong. With a market solution you can be all of those things and it's usually self regulating because you lose your ability to influence anything by blowing your resources on stupid, while people that get it right end up with more resources to bet on their predictions in the future.
No, we spent the last century watching the utter depravity of free market capitalism be reigned in by regulations. Free markets don't maximize public welfare, they maximize profit for successful marketers.
Also maximizing profit for successful individuals in the market is equal to maximizing public welfare IF regulation is successfully mitigating market power and externalities, which is exactly what I have been arguing for here. Everybody knows the outcome of a totally free market is monopoly and there is a role for government in breaking up/regulating those potential monopolies to mitigate their market power as well as in spots where there are natural externalities that need to be priced in. That I seem to have to recap all of this before making an argument that a specific regulation is incorrect is a bit concerning, as the above is basically settled in economics and the current argument is what should be regulated and how (which is the discussion we are having here regarding a national speed limit on flying and how it is incorrect to argue who changing the law will benefit regarding carbon output when we can just tax the carbon at the amount that most likely covers the externality and not have to make those judgement calls (and risk getting them wrong as we often do).)
Or get executed, as happened with China's 2008 milk adulteration scandal.
In terms of climate change, there isn't really any budget of "safe" CO2 emissions left -- we've used it all up by largely ignoring the problem up until now.
The world can't realistically just stop using fossil fuels right now, because so much of our infrastructure depends on it. But we can stop wasting fuel on things we don't need. One of those things we don't need is the vast majority of air traffic that isn't transporting high-value time-critical cargo or getting people where they need to go to complete a specific job (and if it could have been done with a Skype call then no, it isn't a need).
So the 'Forever chemicals' cannot be removed from the environment now, they are in the blood of thousands of people and in the water.
The fine should be infinite?
Banning something is a solution that prevents some people from doing what they want. Taxing something is a solution that subjects a (potentially much) larger group of people to a reporting and tax burden and random inspections. If it's authoritarianism you are concerned about, you have to contrast the sizes of these groups and the potential harms from the banning and tax collection to determine which solution is worse.
Regulation is difficult, especially when you are trying to outwit the market.
I have no idea what you think a passenger jet would switch to?
If writing regulations that have the intended effect without significant downsides was as easy as you suggest, tax planning would not be a big business.
It's not like a whole airline can get away with not reporting how much fuel they buy, and a carbon tax would apply to all their fuels.
Many taxes are complicated and flawed, but this kind is already good to go.
How do you deal with refueling at international destinations and possible carbon taxes in the destination country?
Do you actually want to tax carbon emissions or climate impact? A synthetic fuel could plausibly be carbon neutral, but burning it at the cruising altitude would still have an impact on climate change.
A business with other things has no advantage or disadvantage.
> How do you deal with refueling at international destinations and possible carbon taxes in the destination country?
Pick an option. It won't make much difference.
> Do you actually want to tax carbon emissions or climate impact? A synthetic fuel could plausibly be carbon neutral, but burning it at the cruising altitude would still have an impact on climate change.
We can have that as a possibility. Probably it's worth wording the law so that the tax scales with the remediation cost.
Second, international refueling has historically been the main reason why jet fuel cannot be taxed properly. In many European countries, gas has long been much more expensive than jet fuel. If you try taxing jet fuel without coordinating the tax scheme with nearby countries, the end result is increased emissions. Planes will refuel under a more favorable tax regime, fly with a heavier fuel load, and maybe even trade some payload for fuel. Airlines may also route their flights suboptimally to take better advantage of cheaper fuel.
Third, if you want to tax climate impact, it's not enough to tax fuel. You have to collect data on where the fuel is actually used and build new systems for ensuring that the reported data is correct. And then you need a model for calculating taxes from the data, which is going to be a politically contested issue. Especially when the model is changed according to the latest scientific understanding.
I don't see how business structure affects my suggestion at all. The main tax would be on fuel purchases.
> Second, international refueling has historically been the main reason why jet fuel cannot be taxed properly.
So make it an EU thing. And the US can do pretty well by itself despite that.
And you can charge planes at landing based on any fuel they recently used that wasn't taxed enough.
> Third, if you want to tax climate impact, it's not enough to tax fuel. You have to collect data
Nah you don't have to do that. Don't let the perfect be the enemy of the good, and don't try to make taxes too complicated.
Including fuel used by trucks when the same fuel could also be used in planes? If you tax it, businesses that operate both trucks and planes are at disadvantage. If you don't, you create opportunities for tax evasion.
> So make it an EU thing. And the US can do pretty well by itself despite that.
The EU has to deal with major hubs outside its regulations in London and Istanbul. As for the US, Toronto is conveniently located for many domestic routes.
> And you can charge planes at landing based on any fuel they recently used that wasn't taxed enough.
Assuming that you are allowed to do that, according to various tax treaties and free trade agreements you would like to keep.
> Nah you don't have to do that. Don't let the perfect be the enemy of the good, and don't try to make taxes too complicated.
Unfortunately it's 2023 and not 2003. The window of opportunity for a good outcome has already closed, and even an ok outcome requires understanding the difference between carbon neutral and climate neutral.
And as I mentioned, there is an alternative to making taxes too complicated: banning activities that are obviously wasteful.
That we have a multi billion dollar industry designed to assist with this process?
Are you aware of the bottomless pit of fraud the carbon yax credita have become?
Or that 80% of plastic recycling and electrinics recycling is fake?
Carbon credits don't even resemble a fuel tax. That fraud doesn't matter here.
Why is fake recycling relevant to a discussion of taxes?
If we can offset "the expense of everyone else" (in this case via a carbon tax), why not?
Unless you use that tax to pay someone to clean the air?
If we wanted to massively fund air cleaning, which I'm in favor of doing, we should use a tax as funding from day one.
The proper argument is to get a carbon tax first before unbanning anything like this.
And it's not on the political horizon so....
And anyway, forests are not carbon-negative; all that lives must die. They're carbon-neutral.
Carbon taxes, on the other hand, are an effective solution to global warming.
... at the same altitude.
Looking it up, the Concorde flew at 60,000 ft, compared to normal planes at 30,000 ft.
And atmospheric pressure at 60k ft is less than a quarter of what it is at 30k.
Is it possible to fly twice the speed of a regular aircraft but without using that much more fuel, by flying higher? Or does the plane have to burn even more fuel to get up to that altitude and maintain lift in a thinner atmosphere?
You do need more energy to go that high and fast, but it take a bit of analysis to figure out if it's problematic. Most likely it would be driven by the mission profile as to whether or not the trade-off is worth making.
"In the days when the supersonic transport was in active service, and cruising at between 60 and 68,000 feet, the estimated radiation received by the crew was 50-130 mSv/yr. thus, obviously, as newer generations of aircraft cruise ever higher, by the time we reach altitudes above 60,000 feet, it is entirely possible that, especially with crews flying trans-Atlantic or transpolar routes, the acceptable maximum safe dose of radiation per year will be exceeded. In addition, these numbers do not take into account the possibility of pregnancy in female crewmembers. "
See Van Allen Belts.
If I edit my photos on the flight home, am I more likely to corrupt my files with bit flips?
As long as nothing ever seems to be mysteriously off course and heading for Moscow it sounds like a great idea. Is it easy to distinguish a ballistic missile full of passengers from the more bad kind?
But I was more curious about the fuel efficiency...
It turns out that higher cruising altitude isn’t nearly as useful as atmospheric pressure might suggest. Aircraft end up optimized for their cruising altitude, but there’s a lot of tradeoffs when targeting a higher altitude.
If you go higher, the speed of sound decreases so you have to go slower to avoid going above the critical Mach number for your aircraft. Normal airliners have to stay quite a bit below Mach 1 to avoid any part of the airflow going supersonic, since that would create big issues like shock waves making the aircraft uncontrollable.
But due to the air being really thin, you also have to go faster. Otherwise your wings will not generate enough lift to keep flying.
At some point you cannot go faster and you cannot go slower, that effect is called Coffin Corner and limits how high a subsonic airliner could fly: https://en.wikipedia.org/wiki/Coffin_corner_(aerodynamics)
The turbofan engines of today mitigate this inefficiency by, in essence, strapping a big prop in front of the turbine, except we call it a fan.
Props employ lift like a wing. Fans are screws.
It's really a spectrum where most props & fans actually posess at least a little of both properties, and there are some in the middle that had to simply be called propfans.
If you want to compare apples to apples, I suggest you refer to the 2 metrics I mentioned: - gallons of fuel per miles flown - fuel used per passenger
One without the other is a useless comparison as you pointed out.
So, for the blackbird, how does it do on take off? You know, when it is literally leaking fuel? :)
Down thread it was pointed out that sports cars are more efficient than busses. Per vehicle. This is about the same idea, at best.
The SR-71 had a maximum takeoff weight of 140,000lbs.
The 747 has a maximum takeoff weight of 735,000-910,000 lbs, depending on model.
That helps quite a bit for the former using less fuel per mile.
The bus wins when carrying 3 or more passengers besides the driver. And in a city with dedicated bus lanes, the bus may win for route speed, too.
If we want to improve lives of workers, I am game, but can we start by helping all the amazon can drivers that pee in a bottle?
Why does designing a Ferrari have anything to do with your broken society? It’s not about the Ferrari - it’s about middle class upwards being cheap. Pay higher taxes and your problems on “improve live of workers” will go away.
I pay approx. 60-65% on my gross income. Do the same and we can start talking again.
Oof, I would be carefull eith that, it could be interpreted as a bribe and get you in trouble
You what would actuslly help? Start a union, run it well.
This is not actually true. Drag is at max at around mach 1. After that it goes down again. If you go fast enough you can be very efficient.
The gain comes from being able to fly in thinner air if the plan be is designed to survive the the transonic regime and supercuise, because mach speed becomes lower higher you fly and the air thinner, so lift available to subsonic planes is limited
Limiting proxy metrics, almost as speed instead of noise, when the limit is pretty easy to enforce doesn't do anything other than stifling innovation.
The root of all this is really just that the pollution from fossil fuels needs to be paid for.
Just tax fuel to price in the externality and let people decide how much they want to spend?
> Flying faster than mach-1 to save time will be reserved to a small elite. How does it benefit the masses?
The elite are also people.
How much should it be taxed to factor in the external cost?
I don't know. But that can be treated as a technical problem to figure out. (Problems being technical is good! Much more tractable than political or social problems.)
> Air fuel is taxed very little due to the Chicago convention.
I'm not quite sure how much the Chicago convention would hinder a clever law drafter. Judging by what I can see at Wikipedia on it, I would imagine you could technically tax not kerosene itself, but the burning of kerosene inside your airspace.
Let’s just fly around really fast and enjoy it for the next century or os.
The more demand there is, the more incentive there is for carbon-reducing companies to arise.