Why Aren't Commercial Jets Getting Faster?

Airplanes are one of the quickest ways to get anywhere, but commercial jets haven't gotten much fast since the 1950's. Why is that?
Hosted by: Hank Green
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Sources:
web.mit.edu/2.972/www/reports...
www.grc.nasa.gov/www/k-12/air...
www.encyclopedia.com/science-...
history.nasa.gov/SP-367/f86.htm
practicalaero.com/wp-content/...
www.smithsonianmag.com/histor...
www.britannica.com/technology...
www.britannica.com/technology...
www.pbs.org/wgbh/nova/space/a...
designmuseum.org/design/concorde
• A Surprisingly Simple ...
www.popsci.com/concorde-anniv...
www.theatlantic.com/technolog...
www.airspacemag.com/flight-to...
westegg.com/inflation/
www.nasa.gov/press-release/na...
engineering.mit.edu/engage/as...
theicct.org/publications/fuel...
www.grc.nasa.gov/WWW/k-12/UEE...
www.space.com/16709-breaking-...
www.fighter-planes.com/jetmac...

[@6pistons]

The Concord was one thirsty bird

[@agsystems8220]

For it's time, not really. All jet aircraft at the time were using engines that peaked in efficiency at around mach 2, which meant Concorde made up for the inefficiency of supersonic lift by increased efficiency of it's engines. This was also the primary driver for the early speed. The faster you go, the more efficient the flight, up till transonic effects kick in. The main progress that has been made has actually been being able to go slowly efficiently. Now we don't need to make the aerodynamic compromises of the 60s jets to fly fast so that the engines work well. Now we can fly more aerodynamically efficiently (but slightly slower), without compromising thrust efficiency.

[@alveolate]

@@agsystems8220 so the Concorde _and its friends_ were all thirsty birds

[@Kyle-gw6qp]

Concord was not that practical and was doomed to fail

[@bocahdongo7769]

@@agsystems8220 At 1960-s dear. all plane used turbojet engine, hence people said that efficiency should be around supersonic speed since most of supersonic plane at that time used turbojet engine. But, the day that turbojet used in commercial plane was already long gone when high-bypass turbofan came along same time when Concorde start to fly

[@tituswilliams8063]

Le concorde had been stoped by UE because the patent could not be shared with UE according to french laws

[@alvarodr7619]

the concorde was SO pretty :(

[@EverythingScience]

As with seemingly all transportation technology lately: efficiency>>>speed

[@aggyz2198]

With some technologies such as the maglev and bullet trains both speed and efficiency increase.

[@jettsioson2799]

AggYz ツ but then cost goes up

[@florianh.6256]

@@aggyz2198 Until they reach the same barrier as planes. And at lower speeds as they have to deal with the air density on NN.

[@aggyz2198]

@@jettsioson2799 Yes but you make more money :|

[@aggyz2198]

@@florianh.6256 Yes the fact the trains haven't reached the speed/efficiency barrier as planes might signify that planes have little to nothing to improve on whilst trains have a further future in development and innovations.

[@yeeturmcbeetur8197]

How to make them faster: Muscle hank throw plane harder.

[@seafoam6119]

give this man a nobel peace prize.

[@cpark2570]

"We have a Hulk." Air carbon emissions solved. Boom.

[@alveolate]

muscle hank needs to reply here

[@OhioUltimate979]

The proper term from Muscle Hank is Hunk.

[@abhishekghatge1704]

Knows the answer but still watches.

[@kimberlyw2591]

AE student mood

[@PastaTurtle]

lol yes

[@kuishikama348]

As an aerospace engineer, a few additional comments: - For most wings its actually the low pressure on top side of the airfoil thats responsible for most of the lift, and not the high pressure on the lower side. The wing is not pushed up, but instead pulled-up by the suction of the low pressure side. - Main problem of the concorde was, that is was originally planned to fly over land in US domestic flights. The acoustic of the shockwave made this impossible though. Windows would shatter and people would complain (for good reason). Modern approaches to faster than sound civil aircraft therefore focus on that. See for example NASA low-boom program ( www.nasa.gov/X59 ). Fuel consumption was a problem and it is basically always a problem, but not as bad as the acoustics which limited the aircraft to just a few possible routes.

[@Brahmdagh]

Hi What is the very best explanation of "sound barrier" that you have ever come across?

[@marcoskunrath5914]

Ok, i think i understand what you meant; that the pressure above is lower than the pressure below is higher. Therefore, the low pressure above is responsible for most of the net force. But, pressure is pressure and it will exert a force perpendicular to surfaces it contacts. So the low pressure above still creates a downward force. The airfoil only gains lift because that force is subdued by the upward force from below. Is there a facet I'm missing?

[@mikewhite3530]

@@marcoskunrath5914 yeah, basically the "aerospace engineer" is incorrect, but so is scishow, and it's a very common misconception that is debunked on NASA's website. There IS lower pressure above the wing and higher pressure below, but there is no pulling force anywhere, the high pressure wants to equalize and that means going to the low pressure area and pushes the wing up. But that is a very small amount of the lift created by the airfoil. Most of the lift comes from flow turning, the air above the airfoil is sped up by Bernoulli's principal and redirected downward by the Coanda effect. Newton's 3rd law says that any air pushed down has an equal and opposite reaction and so the wing is pushed upward.

[@suzramuse]

@@mikewhite3530 I'm glad I waited to watch this until after your reply. Now I just have to put it all together. I'm having a little trouble w/Bernoulli's principal. I'll try again tomorrow morning when I'm fresh. & Go to NASA!

[@martinkuffer5643]

@@marcoskunrath5914 I think he means that if you've got a wing and wanna fly you can do two things to get lift: a) make the pressure above the wing lower, or b) make the pressure below the wing higher. Of course the force will always be made by the air below it pushing it up, but from a design perspective you can get force by doing either of those things. So what I think he meant isn't that the force is done by the air above, but that most of the pressure is obtained by method a) and not method b). Disclaimer, I'm a phycicist, not an engineer and I haven't even taken a fluid mechanics course, so don't take me as an authority on the subject

[@wwrk25]

When I was a kid in the 1960's you could hear sonic booms many times in the day. They got to be routine to hear them.

[@detachsoup6061]

I live in the path of millitary training routes and often see fighter jets fly over, i dont hear it daily but once every few weeks, i think its cool (F16 from the dutch airforce)

[@sirBrouwer]

@@detachsoup6061 i always thought that (outside of a actual danger) F16's where not allowed to go over the sound limit. do to the effect the boom can have on equipment on the ground. they used to fly over quite often in the 90's (Zeeland) but always just a bit below the sound barrier. only when they where above the north sea would they go over the barrier.

[@jamesriggs6210]

@@detachsoup6061 does it sound like an explosion or more like the rumble of thunder? I've never had the experience of hearing a sonic boom from a jet.

[@ashley587]

@@sirBrouwer Fighters train at supersonic speeds over designated training ranges (land or sea) where no-one can be bothered by noise. It's not a matter of risk to equipment, it's just loud and potentially harmful to people's ears and wildlife. I should add, fighters are incredibly loud even without going supersonic; loud enough to damage hearing at certain altitudes and speeds.

[@ashley587]

@@jamesriggs6210 If a fighter goes supersonic at low altitude, the boom will sound like a very loud gunshot. At 30,000 feet / 10km, however, the plane would be too far to pose a risk to your ears. You'll still hear it as a low rumble, though.

[@bhami]

The Convair 990A is still the fastest non-supersonic commercial transport to have ever been produced. During May 1961, one of the pre-production 990 prototype aircraft set a record of .97 Mach in level flight at an altitude of 22,500 ft. (6.9 km), equivalent to a true airspeed of 675 mph (1 086 km/h).

[@ElPikminMaster]

I read the title and thought this was a Wendover Productions or Real Engineering video.

[@spartaninvirginia]

Wendover made basically this exact video a few years back, that's why.

[@GeorgeVCohea-dw7ou]

@@spartaninvirginia Which plane topic has Wendover not done yet‽ If you only consider it, just like The Simpsons, Wendover already did it! kzbin.info/www/bejne/jJ-cc5iEbbN1l6M

[@zachcrawford5]

If the air is getting in the way, just "fly" over it.

[@varunjaihind3904]

SpaceX planning rocket trips between cities.

[@OsborneCox.69.420]

SigmaTauri2 wrong.

[@Dr.Hiccup]

@SigmaTauri2 ah yes, I'd love to take a train from the US to Europe lol

[@lordelliott42]

@SigmaTauri2 I wouldn't just assume that the amount of fuel used is per person per unit of distance is lower with a train, and the "carbon footprint" is a lot more complicated that just how much fuel was burned. Besides that, trains have a much bigger impact on the land (because of all the tracks) and therefore environment.

[@zachcrawford5]

@SigmaTauri2 I agree, it just hard to get over oceans on trains (for now) and they are confined to tracks. There certainly ways to fly or even "jump" over the atmosphere without burning fossil fuels. Using hydrogen fuel derived from electrolysing seawater, using green energy or nuclear is probably the most compatible with current infrastructure. But directed wireless energy transfer to electric aircraft is more efficent as you can make the aircraft much lighter, though you can't hop over the atmosphere with it and a whole infrastucture of computer controlled microwave lasers would have to be built.

[@AverytheCubanAmerican]

Concorde: Speed, I am speed 2003: *Not anymore* I've been to the Intrepid museum and got a tour of their Concorde. We had the plane to ourselves. Their Concorde has the record for the fastest Transatlantic crossing by any Concorde. I even got to sit in the cockpit, it was such a fun experience.

[@PaulPaulPaulson]

if air slows you down you aren't flying high enough!

[@dinkledankle]

You almost got me.

[@muninrob]

@@dinkledankle He's actually right. Part of why the SR-71 was so fast wasn't just those two beastly turbines. It was also the fact that air at the altitudes she operated at, the air is not only too thin to breath, but it's actually so thin the control surfaces start have trouble hitting enough air molecules to do their job. An SR-71 at operating altitude is one of the few (if not the only) instances where the turning radius improves as you put on speed. Also, check out the speeds the space shuttle reaches, both on the start of her controlled flight back(after re-entry burn), and the speed she'll do in orbit.

[@arzentvm]

#ElonMuskIdeas

[@Mazaroth]

@@muninrob Walter: Well, we do have one option. However, it was decommissioned in 1998. Alucard: The Lockheed SR-71 Blackbird. An advanced long-range strategic reconnaissance aircraft capable of Mach 3 at an altitude of 85,000 feet. Integra: You sure do seem to know a lot about it. Alucard: DO YOU EVEN READ MY CHRISTMAS LIST?!

[@alveolate]

@@arzentvm musk would open his factory in a pandemic just to send 2 guys into orbit tho. he's getting weirder by the minute.

[@Tullio238]

Feels really weird to have Concorde explained like this when I can recall the last flight

[@alveolate]

that's 17 years ago man.

[@kral3046]

Damn, you're getting old man..

[@DeathDealer_1021]

Dude, you have the default PFP and your username is just your regular name. You're old.

[@brendaoluwalana186]

Say that again?

[@TopLob]

Any time there's a question about why something can't go faster or farther, the answer is always: physics.

[@lyndsaybrown8471]

Money has entered the chat

[@andy56duky]

@@lyndsaybrown8471 Money has left the chat.

[@extraemontamontes3618]

honestly to mee it seems more of an economics problem

[@spongebobsquarepants675]

nope

[@robertt9342]

Wait! It's not magic?

[@MartinCHorowitz]

Actually supersonic may make a comeback using suborbital flight, no or less air may make it cheaper to go faster. Skylon is an example of trying to take this approach.

[@andrasbiro3007]

And SpaceX's Starship. Probably will fly long before Skylon.

[@diogonunes1865]

Love the way you completely avoided the complex and ongoing discussion of how exactly airfoils create lift

[@Xxfireman024xX]

It’s not one or the other. It’s both wing shape and angle of attack

[@frankyisadikted]

I dont believe there is an ongoing discussion it's a well understood concept

[@dinkledankle]

It was neither the topic nor point of the video, so maybe you're just bitching.

[@diogonunes1865]

@@dinkledankle ahm, I'm not bitching, I'm praising the fact that they didn't go into it, as lift is not as simple as most people think

[@gabedarrett1301]

I heard lift is partially due to Bernoulli's principle and partially due to air bring deflected downward

[@aneeshmohan5696]

Is this literally a 'Jet Lag'?

[@andy56duky]

That's a drag.

[@thefiringpin8813]

Ba dum tssssss

[@charlesunlimited2510]

SciShow: explains the real issue regarding the concept in a concise and friendly way. The Infographics Show: *YOU WILL NEVER FLY SUPERSONIC!, PEASANT!*

[@jordibuchner]

Well, they're not only not getting faster... ...They're not moving at all.

[@theinternaut1991]

Hehe

[@FourTwenT]

Gud one m8

[@asdax8311]

Not to mention, flying over super sonic speeds can often create a ripple effect in the air that could shatter windows wherever you fly over. That's why the Concorde only did trans Atlantic flights when it remained in service.

[@hgrace0]

Thank you to the patrons who make Sci Show possible

[@allthegoodthings707]

Wow. That means Dennis Quaid spent 100k to fly him and his daughter to London in the Parent Trap remake. True love knows no limits!

[@heccinchonkercat]

Oh I never knew what he was talking about but now I do lol

[@sagacious03]

Neat! Thanks for uploading!

[@wallacesantos0]

3:40 For a moment I thought the Concorde could go back in time

[@keianostephens]

it can go back in time zones hehe

[@alex0589]

Close, by turning the atmosphere back into primordial volcano planet awfulness, kinda

[@Cyberlisk]

For that it would not only have to break the speed of sound, but the speed of light. ;)

[@Madoushi90]

1:07 Could have sworn there was a SciShow episode debunking this.

[@TeKaMOTO]

Veritasium and Minute Physics have made one at least kzbin.info/www/bejne/l3eyZYN4pNGqfMk

[@kazedcat]

But it is correct. There is a pressure differential between underneath the wings and above it and you can measure them. It is just that the main reason is different. It is not the shape of the wing that creates lift it is the angle of attack. The angle of attack causes the air molecule under the wing to pile up creating high pressure. The opposite happens above the wing where the wing going forward creates additional space that the air molecule needs to fill up creating low pressure. This is why kites with thin membrane and does not have an airfoil shape could still fly. The airfoil is needed for efficiency since the shape reduces air vortices that adds drag.

[@truemorpheus]

Take a look here www.grc.nasa.gov/WWW/K-12/airplane/wrong1.html

[@hidaniel1757]

I knew i wasnt the only one

[@dougstubbs9637]

Lift is a gift, but thrust is a must!

[@tomf3150]

August1992, Air France Montreal Paris, average speed 1080 km/h. We landed 1hour earlier. I love jetstreams !

[@jhrjc]

Thanks guys!- Me to all the patreons

[@gowzahr]

As a grad student, I worked in the same office as a guy who was researching inlet distortion, so it was neat to see the stock footage about distortion resistant turbines.

[@jamesj2509]

This video is rather simplistic, hence some of the questions left in the comments. The speeds that actually matter to an aircraft wing are the Mach number and the indicated air speed (because IAS gives an indication of the number of air molecules moving over the wing; true airspeed matters for navigation on the other hand). At typical jet cruising levels, Mach number is used almost exclusively, with the fastest commercial aircraft topping out at around M0.95 but more typically saving fuel by flying in the region of M0.8 to M0.9.

[@WilliamSmith-gj8wc]

thanks scishow patrons

[@keithknows1809]

The airfoil diagram used (at least at the angle shown) would create a void on the rear _underside_ of the wing, giving the opposite effect. The reason people find these diagrams hard to understand is because they almost never depict the correct angle that the wing needs to be in for the explanation to be accurate.

[@bodystomp5302]

That was interesting, thumbs up.

[@Albert-zy6tw]

The last time I was this early the Concorde was still flying.

[@Omar-em7rl]

nice original joke, i bet you were born after the twin towers fell.

[@tatianatub]

@@Omar-em7rl ok boomer

[@Albert-zy6tw]

@@tatianatub don't go to hard on him he lost his uncle at 9/11 he was one of the hijackers.

[@Omar-em7rl]

@@tatianatub again, that joke is about 11 months old now, also not a boomer, we'll probably have a boomer generation starting next year though.

[@Omar-em7rl]

@@Albert-zy6tw the name Omar doesn't just pertain to muslims you know, i could care less about them.

[@ricky91360]

OMG. Two of my favorite things! Hank Green and Aviation in one video! Hank, if you had been holding a kitten the whole video I would have just died of happiness overload. 😂

[@noahkilgus9860]

*Wendover* *Productions* *has* *entered* *the* *chat*

[@aristokatclaude3413]

No no noooooo

[@pr4420]

beat me to it

[@hectorandem2944]

?

[@zaczane]

You guys really need to do a video about the ekranoplanes

[@ahseaton8353]

One way to improve supersonic engine efficiency would be to use "supercruise" engines like they have on the F-22 and F-35 fighters. The can cruise at supersonic speeds without using their extremely inefficient afterburners. Another is modern SST designs are also working on more efficient fuselages that minimize drag and reduce sonic booms, which is what those wave drag shockwaves sound like when they hit the ground. These new designs turn the BOOM into more of a gentle thump.

[@ssiddarth]

I actually had this question in my head just a few days ago 😂

[@AtomicEy]

why aren't commercial Jets going faster? -->Concorde

[@lovecastle7154]

Yep, over 2000kph

[@EduardQualls]

And Concorde is rushing along at the speed of naught. Because the ugly economics of pushing air out of the way beat elevated speed in all methods of transportation. Not to give you any friction.

[@stephen_l1474]

Cody Mcneill which retired. So it seems like it actually became slower.

[@alveolate]

meanwhile, hyperloop can't even get itself off the ground :0

[@ZippyLeroux]

Golden rule of commenting: watch the whole video first. But even if they hadn't addressed your comment before you made it, 'Concorde' is an answer to the question what's the fastest passenger plane in history? The two obvious question's now being begged are: what happened to it, and why isn't there a mo' betta one? Hint: watch the video...

[@AudiophileTubes]

We used to fly on Boeing 707's (Olympic, TWA, PanAm) to Athens, Greece from NYC nonstop in about 8 hours. These days it takes about 9.5 hours for the same nonstop flight. The more efficient turbofan jet engines of today are slower than the gas guzzline turbojets of yesteryear.

[@jmgobeli]

You need to make a video about Boom Technologies. They have a jet called the Overture which is expected to go Mach 2.2 speeds with business-class fares and profitability-a game-changer for airlines and passengers.

[@FatherLicorice]

I love stories with a happy ending.

[@kennethross786]

Another thing: air entering jet engine intakes has to be subsonic. Supersonic military jets have specially designed fairings or cones to break up the air, slowing it down as it enters the intake. The SR'71 even has variable intakes that move in and out because an air break that works at Mach 1.1 won't work at Mach 3.3 and vice-versa. Commercial airliners would have to go through costly design changes to install air breaks.

[@vincentgoudreault9662]

It is not "breaking the air", it is a progressive compression using oblique shock, using variable ramp air intake. Use proper terminology, please.

[@supermacka4000]

The other reason would be the amount of traffic the average airport can handle. Aircraft are asked to slow their speed to fit the time slots therefore even if an aircraft could fly faster they would probably spend more time in a holding pattern.

[@EclipsaMyrtenaster]

Yo big up Mustard for giving me the knowledge about aircrafts

[@shiina_mahiru_9067]

Despite financial difficulties, the Concord also failed because... a slice of metal debris blew up a tire and in turn puncture the fuel tank, causing disaster

[@Anonymous-pm7jf]

So there's that.

[@sebastienh1100]

A slice of metal lost by a Boeing earlier ..

[@talltroll7092]

Concordes' problems were more political than anything else. The idea had been to build a LOT more of them (making the per-unit price much more reasonable) and operate them on many more routes globally, but the problems with the shockwaves and mostly unfounded opposition from the Sierra Club and the likes really restricted the routes they got permission to fly

[@ChrisZoomER]

Nearly all passenger jets are designed to reduce wave drag at near sonic speeds such as streamlining the plane in accordance to with Whitcomb's area rule and by using swept back wings to slow the airflow over the wing down so the plane can fly faster before this air travels supersonic.

[@by9917]

I recall some 40+ years ago, being told that the pressure on the underside of the wing is small compared to the pull from the upper side of the wing. The high speed air over the wing causes reduced pressure pulling, or sucking, the wing up. My memory is not that good, but I think it was stated that 1/3 to 3/4 of the lift is from the top side.

[@notandymarty]

It's all relative. The "sucking" effect is from the lack of air on the top, which is just another way of saying the excess of air on the underside of the wing. It's all the same thing

[@akjelane8781]

Love Scishow

[@allertonoff4]

.. erm .. discreetly hilarious .. superstar !

[@TheTexas1994]

This episode of SciShow is brought to you by Wendover Productions!

[@gonzalomorenoandonaegui2052]

Please more aviation videos ! (or thermodynamics/aerodynamics is cool too)

[@jarencascino7604]

Those original passenger jets looks awesome with the engines in the wings

[@rickseiden1]

"So our flights will be cheaper.." No way that's happening. More like, "so the airlines can increase their profit margins by charging us the same while their costs go down."

[@BirdieRumia]

Not necessarily, actually. Ticket-price comparison sites have had a huge effect on their prices and are largely responsible for a huge drop in ticket price (and corresponding increase in fees to actually stay profitable.)

[@huldu]

That sounds about right. No matter what you're looking at the second prices are suppose to go "down" instead they go up because that's how the real world works.

[@jakubgawrys2763]

That's simply not true. If you look at air ticket prices over long time (to nullify bumps in prices , discount schemes and such) they keep going down and pretty drastically too.

[@Q_QQ_Q]

ask govt for package while sucking us dry

[@martir.7653]

I doubt they will go towards the profits. The airline industry is one of break-neck competition and profit margins are thin. A few airlines went bankrupt every year in Europe, even before the pandemic.

[@diyeana]

We could also develop other ways of travel, like high speed underwater trains or suborbital flights. Suborbital could take you to the other side of the world in less than an hour.

[@thelazarous]

The teardrop shape doesn't make a plane fly and technically isn't even required, they just make the efficiency much better and reduce the total force load on the wing

[@GeFeldz]

Hey, the concorde service was cancelled because of the crashing, not because of the cost. There were lots of rich businesses and indivuduals willing to pay for the speed, however when the birds started crashing because of age and rampant upkeep deficiencies, Concorde became unviable. Crashing at supersonic speeds probably meant instant death for the rich passengers, so the insurance companies probably dodged a few bullets at least... (that last sentence might contain SARCASM, you know, just for clarity's sake)

[@EduardQualls]

I have had the unpleasant experience of flying with "Hurtling Airlines". It was a drag.

[@scotte4765]

Here to support Hank's use of metric units. Too many commenters that are obviously too lazy to open a new window and take 30 seconds to look up a kilometers to miles conversion. Not that hearing "590 miles per hour" is going to be any more meaningful to our everyday experience than hearing "950 kilometers per hour" anyway.

[@larryscott3982]

He left out an important factor: The speed of sound is faster at sea level than a 40,000 ft. And at sea level, given the denser air, it’s far more difficult to get to Mach speed. At sea level 300 mph is fast! At 39,000 ft, 300 mph is called descending. A jet maintaining Mach 0.8 at 20,000 ft is much more difficult than at 39,000 ft. At 20,000 ft Mach 0.8 is faster than at 39,000 ft. And speed of planes is governed by airspeed, not ground speed.

[@brianhiles8164]

I was redirected here by a recent short concerning this very topic, to which I find you address the incidentals that I commented there. _However,_ you mention Bernoulli´s _high-pressure, low-pressure_ standard model of airfoils. Firstly, this is _kind_ of an obsolete model of understanding, but more to the point, you show a new-fangled (well, new-fangled during WW2, I suppose) _laminar flow_ section, which distinguishes itself by having much _less_ reliance on Bernoullian aerodynamics, and much more so on angle-of-attack. _Whoops!_ *:-)*

[@CuddlePhantom]

I'm wondering if engineers have ever tried some sort of barrier/screen to block (and) or redirect the air molecules. some sort of nylon adapted to pop up at a certain speed and stop them from breaking the sound barrier shock wave but still goes faster than it by redirecting and limiting the air but not the device.

[@connecticutaggie]

I just did the math and the SpaceX Starship (which Elon whats to use for suborbital passenger transportation) uses 1,200MT of fuel and has a stated capacity of 100 passengers. That is 12MT/passenger. That makes the Concord seem like a fuel miser. But, that is nothing compared to getting to space (or the moon). The Saturn V used 2,440MT (530,000 gal) of fuel to take 3 passengers the moon. That is over 600MT/passenger; but, that is for a trip to the moon which would be a very rare experience.

[@undertasty]

I hope high altitude flight takes off, no pun intended. The idea is to fly the plane in an altitude so high, the atmosphere is not an issue anymore. Basically it’s like spaceflight, with the benefits of zero or near-zero gravity, meaning being able to fly at great speed without having to use a lot of energy, bc there is little resistance. Smarter minds than mine can tell you why or why not it is possible. Maybe do an episode on it SciShow? 😘

[@samburnes9389]

There’s still pretty much the same gravity up there as down here. The air is thinner, so you run into problems feeding the engines on the plane. You have to go faster to get more air flowing into the engines. But as the air gets thinner, there becomes a point where a certain design can’t go faster without breaking. There are designs that can go faster and higher using different engines

[@WT.....]

In addition to the issue of drag, engine efficiency, and fuel consumption, something that I noticed was not mentioned was the resulting noise from traveling at high speeds. When a plane starts to fly at the speed of sound or faster, they develop a shockwave as mentioned at 2:05 in the video, the transition of compressed air in front of the wing produces a lot of noise called a sonic boom. This 'boom' is comparable to a continuous roar of thunder, and logically, the faster the plane, the louder the boom. According to the 'Oklahoma City Sonic boom' experiments conducted during the mid-1960s, the constant exposure to sonic booms in the urban environment is as you've probably guessed, not a good idea considering the typical height flown by most standard commercial airliners. This reason was part of why Concorde was limited to flights over the Atlantic Ocean.

[@snowthemegaabsol6819]

The pressure differential of air under and over the airfoil isn't what gives a plane lift [technically it does give some lift, but is nowhere near enough to get it off the ground] and not even a major part. How planes get the lift they need to actually maintain flight is by having their wings tilted back [or sections of the wing called control surfaces] slightly so that the bottom of the wing slams into the air in front of the plane, displacing it, and a vacuum is created over the top of the wing. The angle is such that the air is pushed down from the bottom and pulled down from the top, and as an equal and opposite response, the plane is pushed up. It's why planes can fly upside down or with different airfoils that don't take advantage of Bernoulli's principle.

[@smashing_data4292]

Also, people do now want to hear constant sonic booms all the time created by commercial jets. That is why the Concord only provided flights over the ocean.

[@theinternaut1991]

I hate to say it but 1:20 is incorrect; it has been demonstrated that the pressure difference between the two regions (at least with airplanes) is either non-existent or negligible. We still don't fully understand lift, but the main theory (last I heard) was that air molecules strike the underwing and because the wing is angled, this translates into a vector pushing up in the planes wings. Pretty intuitive actually

[@treeperble]

I'd like to see where it has been "demonstrated". In my university aerodynamics class, we put an airfoil in a wind tunnel with pressure ports all along the upper and lower surfaces. There is a significant and quantifiable difference in pressure between the top and bottom of an airfoil. Google "airfoil pressure distribution and you'll see this. You are correct that air being forced downward also plays a part in lift. A much more accurate method used in higher-level calculations uses the circulation around the wing to estimate lift.

[@keenheat3335]

there is also the issue that when super sonic air slow down to subsonic speed it generate huge amount of heat. Combustion efficiency is proportional compression ratio. If the incoming air is already hot, you can't really compress the air too much further until the heat start melting the engine combustion chamber. So given the same material temperature limit, a super sonic engine will always be less fuel efficient than subsonic engine due the much lower compression ratio. Adding to the flight cost.

[@DanielSmith-uy3yg]

Actually I remember watching a video that explained that the Concord was quite financially viable but was retired for political and company image reasons...

[@vincentgoudreault9662]

Financially viable IF you dismiss the cost of developing and testing it. They made 20 airframe total, only 14 actually went in service. The development cost comes to almost $1 billion per airplane that actually made into service in today's money.

[@vincentrobinette1507]

The runway accident didn't exactly help either: That was the final "nail in the coffin".

[@zachcrawford5]

The heat generated on the leading edges of the plane at super-mach speeds could be turned into a benefit by running the fuel lines through the leading edges. This will cool those edges and would preheat the fuel so that it can be burned more efficiently.

[@imjashingyou3461]

Planes are also dramatically more fuel efficent, maintenance efficient, and inflation adjusted cheaper to buy. Progress occurs in different ways.

[@michaelposey3321]

Idea: use the dents from a golf ball on the planes. I watched a thing about how on a car those dents improve fuel efficiency so possibly it could help get rid of those pockets of air that heated up that one jet cause it would improve air flow.

[@nathanchildress5596]

That only works on golf balls because they're tiny and spin as they "fly" which creates a layer of air around the ball which lowers friction. On a plane they would just make turbulence and drag....and probably make it drop out of the sky because the airflow would separate from the wing.

[@paulrdgers3914]

efficiency is great & all, but we must be sure to remember the words of a very wise man: "SPEEEED!! AND POWEERRR!!"

[@aldenheterodyne2833]

We could build vacuum trains you know. You build a straight tunnel that can be made airtight (or at least low pressure) then you put a train on a magnetic rail, then you can go as fast as the fragile human bodies inside allow you to go.

[@danroth7260]

“Don’t blame the engineers!” I don’t know...this sounds an awful lot like an engineering problem to me ;p

[@BigMobe]

Engineers just use the information scientists gather. It's a science problem.

[@Kycilak]

@@BigMobe But maybe there's already an observed effect that could be used by an engineer. We shall never know who's at fault.

[@JonathanRossRogers]

The engineering problem was solved to produce the Concorde. The fact that people aren't generally willing to spend $50,000 to cross the Atlantic is an economics problem.

[@oldmech619]

I was in a plane that was doing a test flight. We did an emergency decent test. That caused shockwaves all over the tops of the wings. Really something to see, but as a passenger, I hope you never do.

[@grotbagsz9261]

Came for Mach critical, was not disapointed

[@blackmamba1261]

The airfoil and clouds in the diagram at 1:07 look like a face. You also cannot unsee it once you see it

[@vincentrobinette1507]

That same phenomenon is also what limited the top speed of open propeller airplanes. If the tips of the propellers exceeded mach 1, the tips lost their lift, making the propeller effectively smaller in diameter.(and oh, the noise!!!) They were limited to ~600-640 kilometers per hour.

[@Krebssssssss]

4 hours from New York to Los Angeles is too slow for some people? That used to take several years! At the turn of the 20th Century, Chicago to Salt Lake City by train took almost a week! A typical trip by car that takes 12 hours, a plane can get you there in one. Give me about six inches more in leg room, a slightly wider seat, so we're not packed in like sardines, and it's fine. You can start out in San Francisco or Los Angeles, and in like 8 hours, you can be in Paris, standing in front of the Eiffel Tower. That's pretty incredible to me.

[@nolakillabeast]

I have been building and flying rc planes for a long time. As a kid, my first plane was a cessna and I kept trying to make it faster, until I realized that at some point, flying faster made the aiplane fly very weird. This is when I learned about flight envelope by reading about it. It than became clear that I had to have different planes to do different things. Sure, the real world is like that, but I believed that in rc planes it would be different.Turns out it is not different, as a matter of fact almost identical...well physics hehe. Anyways, learning physics by trial and error along with a passion is SO much fun. To this day, finding the balancing point or correct CG (center of gravity) is a true challenge (even when instructions). A nose heavy plane flies poorly, a tail heavy plane flies once. Again same with the real world, if the cargo is not well distributed, it could have serious effects on the flight enevlope...the more you know :)

[@beefteki]

Bring blimps back!

[@plainspirate]

I wonder if something like the bulbous bowe used on large ships to flatten the waves to improve efficiency, could be used to reduce the effects of wave drag on wings?

[@vincentgoudreault9662]

No. Water density remains constant, while air can compress or dilate. Completely different fluid behavior.

[@markredacted8547]

The wing creates lift from the low pressure above the wing not the high pressure below, otherwise hitting supersonic barriers would cause ordinary aircraft to pitch up out of control, not down like what really happens. Nobody here probably cares but in case you do remember this so you don't look silly in flight school.

[@darraghdomnaigh5178]

Yo ever heard of SpaceX’s Starship, it’s gonna take people round the world in like half an hour

[@FirstNameLastName-qt2hz]

last time i was this early planes still existed

[@livimoon5631]

I know I can always rely on Sci-show to get the correct answers

[@alex0589]

Me, a man of youtubeness, before clicking: Transonic flow! Efficiency! Snatch blocks!

[@aarenfiedler]

I thought the whole high pressure under the wing low pressure over the wing thing had been disproven... And I thought I learn about this on SciShow...

[@samburnes9389]

No, it’s true. It’s just misleading. There is a pressure difference that makes lift (and drag). Pressure is just force per unit area. And lift/drag is the integration of that pressure (and shear stress) around the wing. It’s misleading because it’s not a cause of lift. It’s the way the air flows around the wing, the circulation, that creates the pressure difference which then makes lift. The circulation comes about from the geometry of the wing and viscous effects. So it’s hard to nail down one “cause” of lift

[@ctdaniels7049]

I got this crazy idea where we have flights that are the same duration but they just suck less to be on. 🤔

[@bigpopparasta8133]

Concord... WOO FILTON GANG

[@FlipnKraut]

Lol reducing ticket cost? Like those savings would ever get passed onto the ticket buyers.

[@ArchAngelSlayer1]

If you look at airlines like Spirit, Frontier, and Ryanair, the only thing that keeps them competitive is their price. They objectively suck and the flight is not great but if you can get where you're going for $100 then are you really going to pay twice as much? Most people just endure the suck for a few hours. I don't really buy the idea that airlines aren't striving towards lower ticket costs, especially to have an advantage over their competition.

[@SuperSmashDolls]

Literally all of it gets passed on, that's why they nickel-and-dime you. Margins are razor-thin and airlines get crushed if there's even a $10 difference between their ticket price and the next cheapest option, because literally everybody picks the cheapest option available for their given dates and city pair. Ticket prices have been falling dramatically ever since the liberalization of air travel, even more so when you consider inflation. Tickets used to cost thousands of dollars for something that now costs hundreds.

[@rockets4kids]

On the contrary, the airline industry is one of the most cutthroat out there when it comes to doing everything possible to minimize ticket prices.

[@xcmodev1558]

Heres hoping for Concord II: Electric Boogaloo

[@sakinano99]

the airfoil shape and pressure differential is NOT the most important contribution to lift. otherwise, planes wouldn't be able to fly upside down, but they CAN. instead the angle of attack is the most important contributing factor (i.e. the wing tilting up and pushing air down, which in turn pushes the plane up by newton's 3rd law.

[@todabrilla]

I've heard that this common explanation of lift is probably not entirely accurate.

[@GamerGrimm]

James Albright It's pretty quick, but it is correct-ish, instead of a 'push' it's more like a plane is pulled up into the sky. Look up Bernoulli's principle. That principle of fluid dynamics is actually exactly why planes go up. Newton's laws can help, but that wouldn't cut it alone.

[@woodfur00]

Grimm Sanchez But how is it possible for planes to fly upside down?

[@bgossage]

For low speed flows, it works well enough. Ultimately lift is caused by the physical turning of a flow, which is what it has to do in order to flow over the wing. When the streamlines, which can be thought of as the path an air molecule takes, become curved, pressure changes are introduced which directly lead to a net force on the wing that is (hopefully) in the direction you want it to be, which is upward. The way it was explained to me in my first aerodynamics class was that circulation of the flow leads to lift, and even if the flow is mostly irrotational, viscosity will still influence lift because viscous effects determine the circulation of the flow around the airfoil. The Kutta-Joukowski theorem explains this phenomenon nicely, but keep in mind that it only considers 2-dimensional bodies that satisfy a certain geometric condition. Considering 3-dimensional effects makes this a much more complicated problem.

[@flavius7524]

@@woodfur00 Because you use the control surfaces to stabilize the pressure

[@noslover11]

Yes it's the low pressure on the top that produce most of the lift

[@BlakieTT]

Hank can throw me from Trinidad to the USA just with his muscles alone. No need for plane.

[@Bodragon]

(4:13) - As of January 2020, the price of jet fuel (known as Jet A1), was approximately $650 per metric tonne. Even with the salaries of flight staff taken into account, $50,000 per round trip does sound excessively excessive. >

[@iant2064]

There's a startup Boom that's building a supersonic passenger jet right now. Smaller and 100% business class seating.

[@vincentgoudreault9662]

I expect them to not produce anything valid and go bankrupt within 5 years. Mark my words.