[HN Gopher] Time to end the speed limit in US airspace? ___________________________________________________________________ Time to end the speed limit in US airspace? Author : danboarder Score : 89 points Date : 2023-03-25 16:30 UTC (6 hours ago) (HTM) web link (www.elidourado.com) (TXT) w3m dump (www.elidourado.com) | AlphaCharlie wrote: | The faster the plane goes, the more fuel it consumes due to the | drag increase by the square of the speed. In a world where fossil | fuel is needed to fly airplanes and where oil is causing a | destruction of the world we inhabit, it's dangerous to suggest we | should make the flying industry polluting more than they already | are. | | 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? | raincole wrote: | Maybe it should be replaced with a fuel-per-mile limit? | sroussey wrote: | Maybe fuel per passenger? | panick21_ wrote: | > The faster the plane goes, the more fuel it consumes due to | the drag increase by the square of the speed. | | ... at the same altitude. | mpweiher wrote: | IIRC, that's what made jet planes possible in the first | place. Jet turbines in general, and particularly the first | ones, were horribly inefficient compared to props. However, | they let you fly so much higher that it kind of canceled out. | | 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. | programmer_dude wrote: | Turboprop is also a thing BTW. | Brian_K_White wrote: | I think it's called a fan and not a prop, because it's a | fan and not a prop. | | 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. | [deleted] | crazygringo wrote: | Oh interesting. | | 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? | bombcar wrote: | There's a balance. And the Concorde had to have weird stuff | to get that high but yes - you can get better performance | higher to a point. | gallexme wrote: | Not twice as much I think, but it's definitly more efficent | to fly higher if it's in the efficent envelope of these | engines , just alone cause winds up there are way way | faster which can be very favorable, because of the Coriolis | Effect | klyrs wrote: | Take it just a little further: why not ballistic flight? | Sure, they call it the "vomit comet" for a reason but with | the right marketing and some investment in gravol, I feel | like the zero g portion of the flight should be a selling | point. | Retric wrote: | Which is offset by the need to climb through 30,000 ft on | the way to 60,000 ft. | | 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. | banana_giraffe wrote: | One of the bits of trivia about the Concorde: It nominally | flew at 60k feet, but a "cosmic radiation" sensor was | added, and if went above some limit, they would descend to | 47k feet or lower. | gorgoiler wrote: | I haven't ever thought of cosmic radiation in that way | before. It would be interesting to know more data on the | rate of bit flips when flying at altitude. | | If I edit my photos on the flight home, am I more likely | to corrupt my files with bit flips? | NoZebra120vClip wrote: | I just imagined this as Nethack, where a pilot readout | suddenly says, "Oh wow! Everything looks so cosmic!" and | then everyone/everything in the cabin begins | hallucinating. | 57FkMytWjyFu wrote: | Not sure the quotes are necessary. That's exactly what it | was. | | "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. | zamnos wrote: | Doesn't that also imply that it would be possible to fly a | modified plane at the regular speed of a regular aircraft | at that much higher altitude, and use way less fuel? | Airlines' main cost driver is fuel, so it seems like they'd | take advantage of that as much as possible. | t0mas88 wrote: | It's not that easy. | | 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.wikipe | dia.org/wiki/Coffin_corner_(aerodynamics) | barelysapient wrote: | I think that would require a different plane design since | they'd have less lift at that altitude. | davidw wrote: | Seems like a good job for a carbon tax to change the economic | calculations involved. Perhaps for some, the speed would be | worth it, but they'd be paying for it. | hanniabu wrote: | The more credits they buy, the more expensive they should | become | mLuby wrote: | Yes, because the carbon-emitting companies are having to | buy those credits from carbon-reducing companies. | | The more demand there is, the more incentive there is for | carbon-reducing companies to arise. | snapplebobapple wrote: | This is a terrible argument because it presumes there are no | uses of faster travel that are beneficial. The proper argument | is for a carbon tax that captures the externalities caused by | emitting carbon and then to let individuals decide if they want | to pay that or not for whatever activity they are partaking in. | | 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 | aziaziazi wrote: | What is relevant is the inhabitability of the earth, not who | pays what. | thfuran wrote: | >Whether it benefits the masses or the elite is irrelevant | | 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? | Nextgrid wrote: | > Must we permit everything that might be of benefit to | someone, even if it comes at the expense of everyone else? | | If we can offset "the expense of everyone else" (in this | case via a carbon tax), why not? | thfuran wrote: | Assessing a tax doesn't actually clean the air. All it | does is ensure that only the rich have the right to fuck | everyone else over. If the government committed to | funding carbon capture at a rate of at least as much as | they would've in the counterfactual where there was | instead a ban plus the additional amount funded by the | carbon tax revenue, taxing the externality would probably | be adequate redress, but that isn't ever going to happen. | Nextgrid wrote: | > Assessing a tax doesn't actually clean the air | | Unless you use that tax to pay someone to clean the air? | thfuran wrote: | You have to both put the entirety of the tax towards it | and ensure that the fact that you're funding it through | the tax doesn't decrease the amount of additional funding | you put towards it or else that decrease effectively | decreases the tax rate (at least as far as carbon capture | is concerned). The second part is harder than the first. | snapplebobapple wrote: | Because the problem with carbon is that the cost of | emitting it is not reflected in the market price of the | things emitting it. This is called an externality in | economics. You fix the externality by taxing the carbon | emission at a level that covers the externality. After that | you let the much more efficient market sort out what emits | and what doesn't because it does a far better job than than | any grouping of hacker news commenters expressing what ever | combination of the seven deadly sins you think makes them | hate the most productive people in society. Markets work | and envious, wrathful authoritarians don't. You just end up | with another episode of great moments in unintended | consequences going down that road. | thfuran wrote: | >Markets work and envious, wrathful authoritarians don't. | | 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? | avereveard wrote: | How are fines from fda and epa different than fees? | jltsiren wrote: | If you want to tax something, you have to define it, | measure it, and report it. You need a system for | collecting the taxes, a system for enforcing the | collection, and a system for validating that the reported | numbers are correct. You will need more regulations and | more bureaucracy than if you had simply banned it. | | 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. | Dylan16807 wrote: | That taxation system already exists for jet fuel. Nothing | new needs to be added. | pydry wrote: | >The proper argument is for a carbon tax | | The proper argument is to get a carbon tax _first_ before | unbanning anything like this. | | And it's not on the political horizon so.... | denton-scratch wrote: | Carbon taxes (as they exist now) are a con. You just buy | some carbon credits from some company that is supposedly | carbon-negative, because it plants forests somewhere so | obscure that nobody checks. | | And anyway, forests are _not_ carbon-negative; all that | lives must die. They 're carbon-neutral. | ianburrell wrote: | Carbon tax != carbon credits. Carbon credits are part of | emission trading approach. Carbon tax doesn't need | credits cause uses money. Not being cheatable is one of | the advantages of carbon tax. | dan-robertson wrote: | This seems like a pretty bad reason to want speed limits, | because the thing you actually want to limit is fuel | inefficiency. I think rules should normally try to achieve | their goals through first-order effects rather than second | order effects. | | I don't think wanting fuel efficiency is incompatible with | getting rid of the speed limit rule. | seventytwo wrote: | If we had a robust carbon pollution tax, then this wouldn't be | a problem. The emissions would be priced into the ticket, and | we could all (theoretically) fly easy. | | The root of all this is really just that the pollution from | fossil fuels needs to be paid for. | verandaguy wrote: | I strongly agree with your point, but I think some extra | context is warranted. | | 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. | drewcoo wrote: | > If supersonic transport makes a comeback, it'll be because | the economics will make sense | | And not because it kills the planet less. | | [cue sad trombone] | [deleted] | Nextgrid wrote: | You can offset environmental impact by excise-style taxes | on the polluting activity that are used to subsidize | environmentally-friendly processes elsewhere that would've | otherwise used fossil fuels due to cost. | | 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. | bobthepanda wrote: | IIRC, with aviation fuel it's kind of complicated due to | international treaties on taxation of fuel. | kelseyfrog wrote: | You could, but you could also maintain the status quo. | Not everything needs a market based solution. | Dylan16807 wrote: | You can tax enough to remove 150% of the pollution. I'd | call that much better than the status quo. And that's | before we talk about the usefulness of funneling rich | people money into technology research. | htag wrote: | > It'll fill the niche of richer-than-god people who use jets | to skip highway traffic. | | To skip highway traffic a richer-than-god person would use a | helicopter. Private jets are used for further distances. | AlphaCharlie wrote: | That's a very eloquent way to put it, I agree to it all :) | oliwarner wrote: | Given the ecological cost, the economic balance has to be | thumbed; taxed to the hilt to fund restorative programmes. | | Being absurdly rich shouldn't give you license to destroy the | planet. | CyanBird wrote: | The second niche as a rule of thumb pollutes-more-than-God | already(0) | | 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 | verandaguy wrote: | You're preaching to the choir; human progress isn't | proportional to the number of billionaires with fleets of | Gulfstreams (or rather, if it is, there's almost certainly | no causation there). | aaomidi wrote: | I'm constantly in pain about how much human ingenuity | takes the back seat just to keep the wheels turning in | lives. If we actually tried to meet most of the | requirements for people, creative thinking would | flourish. | seventytwo wrote: | 100%. | | 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. | jandrewrogers wrote: | Isn't Europe evidence of the answer to this question? | [deleted] | bendbro wrote: | > In a world | | > world we inhabit | | > dangerous to suggest | | > benefit the masses | | I hope "the masses" put you in a camp. You need to be | reeducated until you stop writing like this. | | PS. The camp I'm referring to is administrated by a communist | government, so your liberal sensibilities prevent you from | downvoting this comment. | goodluckchuck wrote: | [flagged] | arcticbull wrote: | > Bold claims such as man made climate change require bold | evidence. | | Boy is it a good thing we have it then. | goodluckchuck wrote: | Would you mind sharing it? | AlphaCharlie wrote: | I'm going to assume you are not trolling and hope this | will change your mind, but I am not sure what proof you | expect will convince you. It's worth asking yourself | before reading these what is the level of proof you | require to be convinced, and then see if these are | fulfilling your expectations. | | - from CalTech: https://scienceexchange.caltech.edu/topic | s/sustainability/ev... - from NASA: | https://climate.nasa.gov/evidence/ - from Cornell: https: | //news.cornell.edu/stories/2021/10/more-999-studies-ag... | - from Columbia: | https://news.climate.columbia.edu/2017/04/04/how-we-know- | cli... - See statements from scientific organizations | across the world (in case you the leading schools of the | USA aren't convincing you): https://en.wikipedia.org/wiki | /Scientific_consensus_on_climat... - scientific journal: | https://phys.org/news/2017-11-man-made-climate- | proven.html - united nations: https://www.un.org/en/un- | chronicle/climate-change-disasters-... | | I have not read this one in depth but maybe it will help | change your mind on some misconceptions: | https://skepticalscience.com/ | | I'm happy to link similar studies from across the world | if you speak other languages. | | I know for every link I send you, you will find an equal | number of links from climate change deniers. Put please | put in perspective the number of people on one side of | this issue and the other: the overwhelming majority of | scientists agree. | | And even if they are wrong, is it really that bad to try | to burn less oil and make the air less polluted and our | planet more hospitable? | tormeh wrote: | > The faster the plane goes, the more fuel it consumes due to | the drag increase by the square of the speed | | 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. | avereveard wrote: | Drag goes back from the transonic peak but not below what was | at subsonic speed. | | 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 | TylerE wrote: | You can get around that by flying higher, where the air is | thinner. This is easier if you faster. | looping__lui wrote: | Funnily enough the SR71 at Mach 3.5 had a better mpg than a | Boeing 747 below Mach 1. It's kind of hard to compare apples to | apples here - but at supersonic speed, different engine | technology can be used with better fuel efficiency... | [deleted] | taeric wrote: | You also have to compare getting to that speed. And, of | course, the comparison is dead when done per passenger. Might | as well compare a missile in there, or a drone. | SkyMarshal wrote: | Probably also because it flew much higher with less air | density and drag. | AlphaCharlie wrote: | The SR71 was flying at a much higher altitude to achieve | lower drag and fits 2 pilots, 0 commercial passengers. | | 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. | looping__lui wrote: | U miss the point entirely that supersonic planes work | differently from "traditional" subsonic planes. Just | assuming that "faster equals less fuel efficient" is not | really correct. Turbofan engines are kind of draggy and not | so fuel efficient close to Mach 1. Ramjets change your | equation... :-) | post-it wrote: | A Ferrari probably has better fuel efficiency than a bus, | yeah. | speed_spread wrote: | Are you optimizing for throughput or latency? | looping__lui wrote: | And I guess the brains behind a Ferrari enjoy their work | more than engineers designing said bus. And Ferraris will | attract more attention than a bus. Maybe some things are | just unnecessary. Conquering the useless and doing | unnecessary things is what keeps me sane and happy. But our | mileage on that topic might vary. | dsr_ wrote: | True. An average city bus gets 7 mpg; an 812 Superfast gets | 13mpg. | | 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. | Already__Taken wrote: | Doing what? sat at 70mph, yeh probably. stop/starting | chundling around town I guarantee not. | tormeh wrote: | Drag also works differently at supersonic speeds. | dragonwriter wrote: | > Funnily enough the SR71 at Mach 3.5 had a better mpg than a | Boeing 747 below Mach 1. | | 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. | thfuran wrote: | And a considerably higher percentage of the 747's weight is | passenger/cargo as well. | looping__lui wrote: | [flagged] | gleglegle wrote: | Per passenger? | [deleted] | Retric wrote: | No. | lfowles wrote: | It also only carried 2... | neilv wrote: | For the convenience of the wealthy? | omeysalvi wrote: | "Let's create a nuisance for everyone so that billionaires can | save 20% time in the air" | gamblor956 wrote: | No justification is given for ending the ban. Supersonic places | are expensive enough that supersonic flight will be the exclusive | domain of the wealthy for years. | | I'm okay with not having to deal with the booms if it means the | wealthy are stuck flying the same speed as the rest of us. | chrisbrandow wrote: | The obvious retort is that many modern conveniences began as | expensive goods that we eventually figured out how to scale, or | make more cheaply. It's not as obvious that this counter- | argument is robust, given the known history that we have with | the Concord3. But if the economic is won't work out, they won't | work out. | | But I'm increasingly leery of arguments that imply the best way | to achieve fairness is for everyone to have fewer nice things. | And I say that as someone who thinks we should be taxing the | wealthy at much higher rates than we do. | a0zU wrote: | Even disregarding the sonic boom, why would we even want mediocre | civil pilots to have access to aircraft thag are necessarily more | dangerous and more destructive in the event of a crash? | avidiax wrote: | Planes usually crash at takeoff and landing, hence supersonic | or not doesn't matter for that case. | | Crashing at any other time, sure, there is potentially more | energy in a supersonic plane. I doubt that people on the ground | will know the difference between a plane crashing on them at | 600mph vs 1200mph. | pclmulqdq wrote: | What an amazing scientific experiment: "we flew a fighter jet | over a Texas city to purposely annoy people, and asked how | annoyed they were." Followed by: "only 17 people rated 'very | annoyed' so that's a win." No mention of the number of people who | put down any other annoyance level... | hughw wrote: | And annoyed people won't be able to like, move away from | Galveston and get away from it. It's going to be over the whole | country. Several times a day. I could see suicides rising. | dasil003 wrote: | I'm sure they also have an airtight statistical regression to | determine how annoyed people will be when it's happening 30 | times a day! | fnordpiglet wrote: | In the NYC metro they have a capacity to launch 4200 flights | a day, and to my understanding it's about 3000 in actuality. | So! Enjoy! | rickydroll wrote: | While I don't worry about the impact of sonic booms on humans, | and were concerned about the impact on the rest of the natural | world. | | Like low-level sonic booms, light pollution was never considered | to be a big issue but eventually crossed the threshold where it | now has significant negative impact on animals insects and | plants. My concern is that once little sonic booms become | commonplace and we start noticing the impact on the natural | world, there will be too much money in play to stop the damage. | | https://www.nature.com/articles/d41586-018-00665-7 | | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2627884/ | | https://www.science.org/doi/10.1126/sciadv.abi8322 | | [edit] just remembered another low-level fact that people did not | think was important. Jet contrails significantly increase high- | level cloud cover which alters weather patterns and holds more | heat in the atmosphere. A simple change in flightpath by | modifying altitude by couple thousand feet can eliminate 80% or | more of cultural formation but the airlines won't do it because | of the small amount of additional money it would cost. | Scaevolus wrote: | Isn't the real killer of supersonic commercial flights the | inefficiency? You're using ~5x more fuel to have a flight that's | ~2x faster. I suppose you can recoup the fuel cost with expensive | tickets, but should we encourage even less efficient flights? | | https://theicct.org/new-supersonic-transport-aircraft-fuel-b... | noja wrote: | "..there is something decadent about putting a complete halt to | the development of a key technology simply because a few | otherwise harmless sonic booms might annoy a vocal minority." | | -> _benefit_ a minority? | Awelton wrote: | The low boom aircraft designs are something I haven't seen and | are quite interesting. I have been under a few "non low boom" | supersonics, and they rattle entire buildings and set off car | alarms. | danboarder wrote: | "Fifty years ago today, on March 23, 1973, Alexander P. | Butterfield, the Administrator of the Federal Aviation | Administration, issued a rule that remains one of the most | destructive acts of industrial vandalism in history. ... The rule | imposed a speed limit on US airspace. Not a noise standard, which | would make sense. A speed limit." | | Imagine how quiet hypersonic planes would be now if the rule had | been a based on loudness instead of speed. I imagine getting from | LA to NY in an an hour in near-silence... That would be awesome! | fossuser wrote: | Makes sense to focus on the actual issue (noise) and not speed. | | It'd be awesome to have supersonic commercial aircraft that were | also quiet. I'm excited about YC's Boom and their overature | plane, but it'd be so cool to able to fly coast to coast at | supersonic speeds. | | Hopefully something like this can pass. | [deleted] | jcalvinowens wrote: | This is unbelievably ignorant... the author literally linerally | extrapolates the speed increases of early airliners to today and | says "we could have 2500mph airliners if the FAA didn't stop us". | | If the author had done even cursory research, they would realize | there are many reasons we don't have supersonic passenger | aircraft, none of which have anything to do with government | regulation. Start by reading this: | https://en.m.wikipedia.org/wiki/Supersonic_transport | frompdx wrote: | _I'm struck by the fact that American economic growth went off | the rails in 1973, the same year the overland ban on supersonic | flight came into force._ | | This seems like a hasty conclusion to make. There are plenty of | things that correlate with the stagnation of economic growth. I'm | aware the author goes on to say almost the same thing after | making this statement, but it is clear the author is trying to | offer the ban on supersonic flight over soil to be the cause of | economic stagnation in America. | | _To borrow a term from Ross Douthat, there is something decadent | about putting a complete halt to the development of a key | technology simply because a few otherwise harmless sonic booms | might annoy a vocal minority._ | | I fail to see how there has been a complete halt on the | development of supersonic technology. A ban on supersonic flight | over US soil is not a ban on the development of the technology. | | _We need to get back to doing great things._ | | Who says we aren't? | | _If we want growth--if we want greatness--it's time to make | America boom again._ | | I can't agree with the author's conclusion. Besides, they don't | really make an effort in their article to tie the development of | supersonic flight over land to economic growth. This is more of a | "build it and they will come" conclusion. I don't buy it. | macintux wrote: | > A ban on supersonic flight over US soil is not a ban on the | development of the technology. | | I am not defending the author's economic arguments, but this | sentence is quite dubious. | | Who's going to spend millions (or billions) of dollars | developing better supersonic technology when one of the most | important markets is off-limits? | | (Edit: remove superfluous word.) | frompdx wrote: | _Who 's going to spend millions (or billions) of dollars | developing better supersonic technology when one of the most | important markets is off-limits?_ | | Militaries, for one. But that doesn't mean supersonic flight | is completely off limits to passenger flight. There used to | be regular flights across the Atlantic at supersonic speeds | operated by Air France and British Airways. The last one was | in 2003. Did the Concorde program fail because they couldn't | fly over the CONUS? | panick21_ wrote: | Isn't the whole problem with boom shaping that it requires a | thinner fuselage meaning you transport even fewer people? I just | don't see this being viable. | | Musk has talked for a long time about a supersonic jet that would | fly higher and thus not be heard on the ground. However batteries | would need to get quite a bit better still and it would be a | massive expansive project. | gabereiser wrote: | I live on my sailboat near Cape Canaveral, FL. I hear sonic booms | when SpaceX lands their Falcon9 back on the pad. 1) it's never at | night, usually on weekends or evenings (thank you SpaceX!). 2) | It's an awesome feeling but can leave the less healthy feeling a | bit distraught. 3) Because they are able to land a stage 1 back | at the pad, and that is a huge feat of engineering excellence, | I'll allow it. So awesome! | | _edit_ my point is there are people that aren't as bothered by | it as others and would like to see us do great things as a | species | lumb63 wrote: | The glaring issue I see with this proposal is the author supposes | that people who say that they could "live indefinitely with sonic | booms" have all the facts needed to make that assessment and are | correct, or that they want to live indefinitely with sonic booms. | | People could "live indefinitely" with ionizing radiation (and | non-ionizing, I might add), but that does not mean it does not | impact their health or wellbeing. There are detriments outside of | the immediately obvious "loud noise bothers someone", such as | property damage, ecological destruction, environmental concerns, | health impacts, passenger safety, etc. | | I couldn't disagree more with this. | thejenk wrote: | > Not a noise standard, which would make sense. A speed limit. | | Is enforcing a perceived noise, or even a measured decibel limit | on the ground even realistic? It would be difficult to | investigate reported infractions unless they're consistently | coming from a scheduled route, because the noise level on the | ground depends on more than just the plane. "Supersonic jets that | don't have a lot of headroom on the noise limits in a dry, flat | desert shouldn't fly supersonic through this area because the the | land underneath is shaped like a parabola and it's very humid." | is much more difficult for a pilot to manage and a regulation | body to enforce than "Don't fly faster than this airspeed." | especially when the effect was the same back when the bill was | introduced. | hn_throwaway_99 wrote: | > issued a rule that remains one of the most destructive acts of | industrial vandalism in history. | | Excuse me while I throw up in my mouth. Seriously, f this guy. I | suppose he's in favor of letting us chuck all of our garbage out | of open windows while we drive, too. | | I've heard sonic booms before at air shows, and it's not some | quiet little "beep". They're loud and disturbing. As someone who | values silence, hearing these frequently at any hour of the day | would drive me insane. | | I don't doubt there is technology that can make booms quieter, | but until it's 0, STFU. Sick of people arguing that creating | technology for the benefit of a tiny few (as others have | mentioned, supersonic travel will always be inherently more | inefficient) is OK, the externalities on the rest of the populace | be damned. | yinser wrote: | Tell me you didn't read the paragraph without saying you didn't | read the paragraph. By your own admission the sound is the | problem. The author states the rule should've been written | around sound levels not speed levels. You are governed by | emotions | notahacker wrote: | The author doesn't make a particularly good case for it | though, because it's relatively straightforward to define | whether an aircraft is or isn't exceeding Mach 1 (and even | more straightforward to stay well below it), whereas decibel | levels from a sonic boom depend on the position of the | observer amongst other things, and what's "acceptable" is as | the article discusses still a research problem. Non-US | markets and airframers exist, a first generation Mach 1 | airliner existed and failed to gain traction, people worked | on "low boom" supersonic airliner projects anyway, and if a | working implementation didn't remain purely hypothetical, | Congress is perfectly capable of amending a law. | | He also misses the _much bigger_ impediment to supersonic | jets than a local rule in the US being fuel cost, most | amusingly when he points out that 1973 was the beginning of a | so-called Great Stagnation but somehow misses the oil embargo | and the resulting fears over fuel prices affecting everything | that decade, including killing the demand for Concorde in the | rest of the world and changing airframers ' focus to fuel | economy. I think when he's suggesting that only a "vocal | minority" (which exceeded the number of people ever to have | experienced the rich person's pleasure of supersonic flight) | held us back from linear progress in commercial aviation | speed so we'd all be flying around at Mach 4 by now, he's | also being governed by emotions. | hn_throwaway_99 wrote: | I did read it. Most of it was arguing "Hey, it's not that | bad, we did some tests and only a few folks were really | bothered about it, and some people are bothered by anything, | so screw them!" | | If I decide to go live in the middle of nowhere for some | solitude, I shouldn't have to defend my choices to enjoy that | solitude as "you're just too sensitive!". | yinser wrote: | So you admit then that a speed limit was a poor rule and it | should've been a sound rule and your vitriol was | unjustified? | fwlr wrote: | "I've heard sonic booms before at air shows, and it's not some | quiet little "beep". They're loud and disturbing." | | I highly doubt you've heard a sonic boom at an airshow, it's | illegal to perform them and has been for a long time. A true | sonic boom performed at low altitude at an airshow would blow | out the eardrums of every attendant at the show and all the | windows in every car in the parking lot. Only the military is | allowed to cause them and only for very good reason. There was | a recent case in the UK where fighter jets caused a sonic boom | as they were scrambled to respond to a malfunctioning plane; | the video is here https://m.youtube.com/watch?v=fGR96Zz0dXk and | it had people from over 20km away calling the police to report | that a bomb had gone off somewhere nearby. | | What you've heard at airshows is _close_ to a sonic boom, it's | called "tickling the cone" and it's highly compressed but _not_ | collapsed sound waves. It resembles the regular roar of an | airplane, but packed into a few seconds. Very different to a | sonic boom, which sounds exactly like an explosion. | | (The practical upshot is this strengthens your argument.) | sillysaurusx wrote: | Ok, and from the other side of things, I've never heard a sonic | boom in my life. No idea how loud it is, or what the tradeoffs | are. Shouldn't we get a say? | | More generally, bans on a technology "forever" just seem silly. | It should at least be revisited every decade or so. A decade | brings lots of advancement; maybe there's some clever way of | minimizing the boom from a sonic boom now. | | Or maybe there isn't. But it's not nearly as clear cut as "if | it's >0, ban it. No noise whatsoever!" Like... you've heard | loud motorcycles. Why not argue for those to be banned too? | sroussey wrote: | A sonic boom is quite loud and will shake all the windows of | every home across a state (though only a smaller section of | the state if it is large like California). | | I have not heard them since the Space Shuttle was retired. | | I agree with the forever part in theory. However in politics | (and law) if you leave a door slightly open, then people are | incentivized to open it wide open and "get around" various | rules. | | Permanent "for forever" laws and never that. They are forever | until someone changes them. That's more binary and easier to | reason about than "this sonic boom is better than that sonic | boom so it's ok, and it the 1980s already so let's have at | it!". You set some threshold number, then the politics is | about the number not the booms themselves really. | | If technology has truly advanced enough, people will change | the laws. Done. | | Now as an engineer, I prefer the threshold. But it's so much | easier to change that. You start a company in 1980 and have | so much better tech after 10 years in 1990, but it doesn't | materially change things enough, so you shut down or try and | change the threshold. What do you do? | sillysaurusx wrote: | Implying we have any control over the laws. :) It's | lobbyists all the way down. Outsourcing our freedom to | lobbyists seems like a bad idea in almost every case. | | "Just change the law" is usually not an easy proposal. One | could argue that it shouldn't be. But technology advances | much faster than the law, and having a lag time of decades | doesn't seem optimal in most cases. | lagadu wrote: | You went to airshows where the show was being performed at | airliner cruising altitude of 30-40k feet? | drewg123 wrote: | Did you actually read the article? | | He's proposing allowing sonic booms below certain decibel | limits that are apparently below what any aircraft can achieve | today. So your experience with airshow sonic booms is not | directly relevant. | sroussey wrote: | Once that's a law, it's super easy to get politicians to | alter that number a bit more your way every year. That won't | make news or cause pushback that a binary decision makes. | | No, the better thing is to demonstrate the lower number as | achievable first, then change the rules to go into | production. | yinser wrote: | Are you a politician or want to qualify anything you just | blabbered by showing FAA standards and the influence of | elected officials on their rules? | mastax wrote: | Were those sonic booms from airplanes at cruising altitude, or | from low flying jets showing off? | eviks wrote: | Non sonic boom noise from the airplanes > 0, ban them all? | SkyMarshal wrote: | You only hear them if you live near an airport, and only if | you're right under the landing approach or takeoff route. But | not when they're cruising at 30,000ft, or even if you live | within visual range of the airport but not under the | takeoff/landing path. | denton-scratch wrote: | The French used to fly Mirage jets over the sea near where | my family used to go on seaside holidays - no airport | anywhere near. I don't know what altitude they were flying | at, but you could see them clearly - as long as you looked | at the opposite side of the bay from where the sound came | from. | | To be clear, they boomed, and it was loud and annoying. | SkyMarshal wrote: | Fwiw I was thinking of passenger jets, not military | planes. I don't have a good sense of how loud or quiet | the latter are. | eviks wrote: | So what? The 0 rule is more compassionate than you are, so | it cares about the groups of people you mentioned too! | Bloating wrote: | Taxes! Raise Taxes! But, just raise that other guys taxes | | and, it needs to be cheaper | jedberg wrote: | I think a lot of people here are missing the author's point. It's | not about letting people go faster per se. It's about the fact | that the ban doesn't actually target the right thing. | | The purpose of the Mach 1+ ban is to reduce noise. But if the | goal is to reduce noise, why not just set noise limits? We have | the ability to measure noise, so if the goal is to reduce noise, | set a limit on noise. | | Then let the airplane operators innovate however makes sense for | their business. If you're worried about pollution (which is a | good thing to worry about!) then there should be a separate fuel | per mile limit or a carbon tax. Then they can innovate within | both constraints. | | But the whole point is that the metric being used is wrong -- it | should be noise output, not speed. | TinkersW wrote: | Author never stated what the current noise level is, but in my | experience when I'm in the middle of nowhere and a jet passes | over at cruising altitude, I pretty much can't hear it | | If this changes it so that this is no longer true, then no, | screw this idea. | | Plus the reality is it would just be used by rich people to jet | about, probably emitting much more c02 per mile. | ccooffee wrote: | This is a good summary of the author's point. In a historical | context, it may be the case that the only useful way to enforce | "quiet skies" was to put a speed limit, but that doesn't | account for changes in technology that may enable quiet booms. | | Most commenters in this thread seem to take issue with the | author's assumption that there is no other justification for a | speed limit other than noise reduction. | | Honestly, I find the author's premise to be vaguely reasonable, | but the whole thing is undermined by the god-awful chart which | extrapolates historical aircraft speeds to imply that without | the "speed limit" rule, we would have commercial aircraft | crossing the Atlantic Ocean at 2500 mph. (Per wikipedia[0], the | fastest manned aircraft in history, a SR-71 blackbird flight, | capped out below 2200 mph.) | | [0] https://en.wikipedia.org/wiki/Flight_airspeed_record | jedberg wrote: | Yeah this is a good point. The military was never capped by | speed limits nor fuel costs or pollution limits. And even | they didn't go faster than 2200mph as far as we know. | | Which either means there was no reason to figure out how to | go faster, or they just couldn't do it. If the former, maybe | with commercial pressures there would be a reason to go | faster, but that's unlikely. And with the latter, well I'm | not sure a commercial entity would out-innovate the military- | industrial complex. | hughw wrote: | "as far as we know" -- they're famous though for trotting | out the Blackbird and setting a new public speed record | just exceeding whatever the Soviets had previously | advertised. | flerchin wrote: | In any spot in the country, you can look up and see aircraft, or | contrails, every day, all day. Unless near an airport, you | generally do not hear them at all. Even with boom reduction | technology, booms would be heard by everyone, everyday. This is | _not cool_. The author makes a valid point that the restriction | should be on the noise generated, not the speed, but even the | mitigated booms would not pass a reasonable test. | dghlsakjg wrote: | There is also the qualitative aspect. | | I live near an Air Force base that luckily doesn't do | supersonic stuff. | | Constant white noise, even at a pretty high level is something | that can be tuned out pretty easily. | | I'm not sure the same can be said of singular events like a | sonic boom. | | I think of it like the difference between a lawnmower half a | block away, and a subwoofer the same distance. | dghlsakjg wrote: | It was never all about the noise, SST/Concorde failed on cost. | | Sure it would be cool to fly across the continent in 1/2 the | time, but not at the expense of tens of millions of people having | to know about it | shpx wrote: | > He was briefly startled but went back to fishing in under one | second. | | This was laugh-out-loud funny to me, something a character on the | Silicon Valley show would say. | jmclnx wrote: | Well I am old enough to remember the Sonic Booms. We would get a | warning in the local newspaper (sometimes) and as kids we will | watch outside waiting for the boom and try and find the plane. We | lived fairly close to a base that would test these planes. | | But, some people's windows would crack and some would break due | to the boom, which they had to pay for. So, if this limit is | changed, will the aircraft owners pay people for their broken | windows. | | Back then seeing a plane at any speed was not common event. Now | you look up at just about any time of day and the chances are | very good (like 90%+) you can find a plane. | tpmx wrote: | Can I ask; roughly speaking, how old are you? (Or rather: when | was this?) | [deleted] | smolder wrote: | This is pretty easy to deduce given GP was a kid in the time | leading up to the 1973 rule. | lambdaba wrote: | GPT-4: | | > It is difficult to pinpoint the exact age of the person, | but we can make an educated guess. The individual is | discussing sonic booms and mentions that, as a child, they | lived near a base where planes were being tested. | Supersonic flight testing and sonic booms were more common | during the 1960s and 1970s. If the person was a child | during that time, they could be in their 50s or 60s, or | possibly older. However, without more specific information, | it is not possible to determine their precise age. | | Nothing extraordinary, probably because we've gotten so | used to it so quickly ;). | tiedieconderoga wrote: | Oof. I really hope we aren't moving towards a world where | people start to copy/paste verbose AI-generated | paragraphs without checking the results. Especially not | to answer simple questions like, "about how old is | someone who was a child 50+ years ago?" | | The AI's guess is off by about a decade. If GP remembers | multiple booms, they were probably at least 10 by the | 1973 ban. Most people can't recall memories back to the | moment of their birth, but LLMs often ignore nuanced | contextual facts like that. Or maybe this is another case | of the model living a few years in the past, since | there's a lag in being trained on new data. | | Who knows, but I am troubled that its incorrect answer | was so readily accepted. This is not an important | question, but it would have been easy to double-check. | This comment may be a grim portent of things to come, if | people continue to trust these models so implicitly. | jmclnx wrote: | As someone said I am a "sonic boomer" :) | tpmx wrote: | Thanks! :) | Y_Y wrote: | Ok, sonic boomer | davidw wrote: | I don't really care much one way or the other, but the article | does address this. | | The actual externality is the noise/pressure wave, not the | speed. It makes sense to regulate as close to externalities as | possible, rather than banning sort of related upstream things. | | In other words, if they can do supersonic without booms that | cause problems, go for it. If they're unable to, well, then | they keep flying so as to not produce them. | jmclnx wrote: | I saw that, I find that hard to believe unless they are | flying extremely high. I think height was also mentioned. | | But doesn't flying that high damage the ozone or something ? | I thought that was one of the many reasons the concord was | stopped (Yes, I know the real reason was financial). If so, | many planes flying that high could cause other issues. | | But some people will see if this happens. | Y_Y wrote: | What an unusually sane point. | wrigby wrote: | I can only assume you're being downvoted because folks are | thinking that you can't go supersonic without making a boom. | While this may be true, it doesn't change the fact that you | make a good point - regulation should be made as close to | externalities as possible. If it makes the upstream thing | impossible, then fine, but let's actually regulate what we | want to regulate. | wingspar wrote: | Yes. Experienced numerous Space Shuttle sonic booms. For me | they weren't problematic like broken windows. But would wake | you up. I also remember waiting for the sonic boom from | Columbia, which never came.. | brycewray wrote: | Am in north Texas. That morning, I was watching NASA TV's | coverage of what should've been the mission's safe ending, | and heard multiple sonic booms, closely spaced. This was soon | after Houston had lost comms with Columbia following the | warnings about weird sensor readings, and I said to myself, | "That's weird. That sounds like what a shuttle does when | it's--" . . . and then I stopped, as I slowly began to | realize there might be a terrible reason _why_ Houston had | lost contact. | Procrastes wrote: | My wife used to live on Edward's Air Force Base which has been | a reserved sonic boom corridor all along. Just some learnings | for that lifestyle. Don't keep fragile things on narrow shelves | and you have to glue the bottom of every picture to the wall. | Don't have dogs or get them a xanax prescription. Cat's don't | care. It's not (always) an earthquake when the glass rattles. | And you get used to all of it. | 2-718-281-828 wrote: | if that restriction is lifted then the sonic boom is going to be | the next status symbol of the top .1%ers. | | also - can someone give a tl;dr why that guy is so passionate | about that to begin with? | | > I'm struck by the fact that American economic growth went off | the rails in 1973, the same year the overland ban on supersonic | flight came into force. | | seems like is onto something ... | | > The speed limit cannot be responsible for the entirety of the | Great Stagnation, of course. | | oh, really, no kidding? | verandaguy wrote: | This article comes off as _very_ optimistic, to the point of | making some really bad assumptions and misrepresenting data. | | The bit about sitting in a sonic boom simulator chamber is just | silly -- the author's subjective opinion about the loudness of a | sonic boom has no bearing on reality, and fails to factor in that | sonic booms during e.g. Bongo II (1964) shattered windows not | because of the sheer volume of the sonic booms, but because this | pressure wave would strike the large surface area of a window | nearly all at once, putting a fair amount of energy into it in | doing so. | | Almost as silly is the line extrapolating speed trends in | commercial aviation over time; it reads like xkcd#605. It | completely ignores the different regimes of high-speed flight and | the limitations posed by it. 2,500mph is roughly Mach 3.2 at sea | level, or nearly 3.8 at 60,000ft. At Mach 2, you need to start | seriously considering thermal issues caused by friction related | to parasitic drag and the paint/coating of the aircraft; at Mach | 3, these become primary design constraints, and active cooling | systems have to be deeply integrated into the airframe. This is | to say nothing of the exotic engine design decisions that have to | be made in these regimes. | | Much north of Mach 4, transporting any useful load becomes | borderline impractical in-atmosphere with current technology. | | Ignoring fuel economy issues since I brought this up in a | separate comment: since the introduction of the Concorde, the | major focuses of aviation development have been on safety, | reliability, and automation (all of which are strongly linked). | "We live in the safest era of aviation in history" is an | evergreen statement thanks to those advancements, and aviation | incidents -- while tragic and unfortunately not completely | eliminated yet -- claim fewer lives with each passing year (as a | proportion of passenger-miles travelled). ___________________________________________________________________ (page generated 2023-03-25 23:00 UTC)