How To Design A Plane To Fly At 100,000 Feet?

[@omgitspylot4411]

Fun fact: the U2 flies so high in the atmosphere, it can fly into the temperature inversion in the stratosphere, meaning the speed of sound actually increases again and it can go even faster without exceeding its limitation on laminar airflow. It also makes a very weird flight performance/ coffin corner envelope.

[@xiphosura413]

That could explain why the graph at around 11:33 starts to pinch out but actually opens up again out the other side, you can see the upper limit bend back outwards again. I'm just left wondering how the stall flutter speed can decrease!

[@johndoepker7126]

I have no idea wat you said.....but I DO know wat laminar flow is, and its awesome....thanks to Destin!

[@xiphosura413]

@@stevemadak6255 Where have you been getting this information? What causes the wings to "fold up" but not the plane losing lift first? How on earth would adding more weight to the wingtips in the form of engines help? It was designed for minimum weight. Where did they put the wingtip skids then? If you're gonna claim things that go against all common knowledge, back up your claims if you wanna be believed!

[@call_me_stan5887]

@@xiphosura413 exactly! :)

[@hattrick2219]

@@stevemadak6255 Would like to know your source for the altitude spec. I've never seen a U2 with wing tip engines. Power's claimed repeatedly that he was "at altitude" and did not experience a flameout.

[@RobbieHatley]

Fascinating video. Your closing comment reminds me of an incident in which an F-15 suffered damage to its right wing in a training accident. Just how much damage was impossible to tell because the spray of leaking fuel obscured the pilot's view. The pilot considered ejecting when his plane became uncontrollable and tumbled out of the sky; but he found that above a certain speed, he could regain control. So he decided to attempt to land it. He found that his stall speed had roughly doubled, so he had to land at twice normal landing speed. After landing, on attempting to finally ascertain just how much damage there was to his right wing, he discovered to his shock that he _had no_ right wing! His reaction was to say "Huh! I guess with an F-15, if you get it going fast enough, you're a rocket and you don't _need_ wings!"

[@themindgarage8938]

"He was a fighter pilot they called "Solo Wing Pixy". He was a colleague of the man I seek. Ten years ago, there was a war that engulfed the world: The Belkan War. And in that war was a pilot who trailed across the sky, and disappeared from history. He was a lone mercenary who inspired both fear and admiration. He is the man I seek. And so... With the words of "Solo Wing," the curtain rises."

[@darrengladstone3159]

Scott has a way of plucking obscure but interesting stories out of subjects well studied by most of his audience.

[@philipwhiuk]

@Michael Bishop A few $50 20 mm bullets are a few dangerous projectiles if they miss/go through. The missile explodes.

[@gert-janbonnema]

@@philipwhiuk Yeah but it explodes into thousands of little bullets...

[@ScalarYoutube]

The gau has a much smaller range and accuracy compared to the sidewinder. There wouldve been a high chance of a bullet destroying the sensor array or missing and raining down on whatever is below. Also, the closer you are, the higher the chance of any debris from the collision impacting the air frame and potentially causing mortal damage to the raptor

[@JohnyG29]

@@ScalarKZbin TBH the sidewinder wouldn't have been that accurate either (as in they couldn't accurately predict the exact location it would hit the balloon). Being a heat seeker I assume it had nothing to track from an unpowered balloon, so they just shot the missile in a straight line.

[@ScalarYoutube]

@@JohnyG29 The balloon is white, meaning that the location the light from the sun hits is going to heat up far more than the opposite side in darkness. This means that the top of the balloon would have been hotter and therefore easier to track. There is no way they would've shot an aim-9 if it wasn't the best and most accurate option. As a side note, the sidewinder was equipped with a counterweight instead of a warhead so it is clear that its intention was to disable rather than destroy.

[@jonhare392]

I supported Helios and Pathfinder during the record flight. It got to 97,000 feet at a flight speed of 35 mph. In a head wind of 40 mph it could fly backwards at 5 mph and gain altitude. PMRF had a runway wide enough for it to take off, I was on the side of that runway as it took off.

[@badc3o]

Wow, care to share anything more about your experiences? I'm fascinated with that project. Did they consider using a prop with an electric motor to try and push further? Do you know what composites the plane was built with? Anything special about the wing design? I can imagine the were at least 33m

[@rickrack78]

I worked on the Oxygen and Hydrogen low pressure tanks that were to supply the fuel cell for overnight flight. The solar panels were able to produce more energy ether aircraft required for daylight flight. The extra energy was to be used to run an electrolyzer which then pumped the Hydrogen and Oxygen into their respective tanks. After sunset, they would be used to produce electricity for overnight flight. I also built the high pressure tanks that were underwing on the Helios when it broke up and crashed.

[@cantrell3522]

I used to work for the company that designed and flew Helios on the team for the successor aircraft Sunglider. The guys who had worked on Helios back in the day were always annoyed that everyone brought up the 1 mishap they had, but not the dozens of flights that went off without a hitch both before and after Helios. Seeing the proprietary design methodology for that type of aircraft was amazing. It's like the ultimate extreme of aircraft engineering.

[@leifvejby8023]

That one Helios mishap was an impressive one. I was very impressed by the Helios, and annoyed by the X-plane simulator's inability to fly a model of it, tried several ways. RC-models however were controllable.

[@josephmatthews7698]

Build a hundred bridges they never call you Bridge builder but blow ONE homeless guy under that bridge and all of a sudden you're a ...

[@dreyna14]

Not sure if you've ever looked, but on an airline flight, if the sun angle is parallel to the recompression shocks on the upper surface of the wing(s), they will cast a refractive shadow on the wing. It's pretty easy to see once you spot it and watch it shift for and aft as the airflow changes from speed and/or turbulence.

[@ThatBoomerDude56]

"fore and aft" 😁

[@jtjames79]

@@ThatBoomerDude56 "four and apht" 🥸

[@martinputz8010]

For reference to what you are saying, I found this video: kzbin.info/www/bejne/fpbOk3ZshdFnlbs

[@cjmatulka8321]

I'll up the subject of light refraction, on a plane load of sleeping passengers near Greenland for about 90 seconds I witnessed a miniature aura 25 yards off the wingtip an hour after the Sun had set. One of the best phenomena I have ever seen, being from Alaska the incident reminded me of the "foo fighters" phenomena. A bit off topic but cheers just the same!

[@theussmirage]

@@jtjames79 "'fɔːr' and 'æft'" 🤓

[@MrHws5mp]

Coincidentally, I've just been reading the latest _Aeroplane_ magazine, which has an interview with USN vet, entrepreneur and record-setter Doug Matthews. In 2013, doing time-to-climb class records in a P-51 Mustang, he hit 42,300 feet (unpressurised cockpit, no pressure suit...). As he was passing 40k, he overheard this convo between an airliner and Miami Centre: "Miami, Delta 1479, requesting our descent." "Delta 1479, I'm going to give you a slight delay. There's an aircraft crossing your nose at 40 and climbing out. It's a WWII fighter." "Say again, Miami?" "There's a North American P-51 climbing through your altitude." "Oh. _Wow..._ "🤣😎😎😎

[@martijn9568]

That intercooled two stage supercharged Packard Merlin V-12 is nothing to be sneezed at.

[@waynerussell6401]

Another: “I remember saying, ‘Christchurch this is Golf Charlie Foxtrot. I am at 35,000 ft descending over Porters Pass. I think I have a world record.’ The exuberant response gave me a thrill. ‘Congratulations. If you look down you will probably see the DC 6 coming in from Australia.’ I looked down, and there, 20,000 ft below I could see a tiny little aeroplane. It was a nice moment.” Dick Georgeson, wave pioneer, December 16, 1960, near Horarata just south of Christchurch, New Zealand. Lucky to be alive with frostbite to hands and feet.

[@allangibson8494]

And a Spitfire XIX reached 51,550ft over Hong Kong in 1952… The pilot lost control on descent and reached Mach 0.96 on the way down…

[@jozsefsandor671]

P-51 was a shit in a comparison with ME-262

[@Inkling777]

@@jozsefsandor671 The P-51 could fly from SE England to Berlin and back. No ME-262 could come close to doing that.

[@dylanhalifaux]

The more I learn about the U-2 the more I respect the pilots.

[@stinkyfungus]

Titanic testis... carbon fiber, instead of the usual Brass ones they issue fighter pilots. Strictly to save weight and eek out an extra 1,000 feet into coffin corner, Doncha know 😜

[@Thatonedude90]

My uncle is a pilot. Pretty interesting stories

[@sietuuba]

@@stinkyfungus eke out ;)

[@phmwu7368]

Read about the post Cuba crisis monitoring og the island and You'll be amazed by the 1963-1966 Lockheed U-2 operational stories !

[@DrDeuteron]

and the ER-2

[@Dynamic_Flyer]

That’s a really good video and captures all the main points. All I would add is that stall speed does start to increase if you climb high enough; it only stays constant up to about 10,000 ft then slowly increases due to Reynolds number (viscosity and density related) effects until about 35,000 ft, at which point Mach effects start to become dominant. Because a given Mach number has a decreasing IAS as you climb, this means the wing suffers low speed “shock stall” at high angles of attack (AOA), but typically at lower AOA than a normal stall. As an example, an aircraft that stalls at 100 kt IAS at sea level could stall at 130 kt at 40,000 ft. This problem gets worse until the top of the tropopause, about 65,000 ft, at which point the stall speed for a subsonic aircraft starts to reduce again slightly due to stratospheric temperature increasing with altitude. This phenomenon is exploited by the U-2, as shown in the video, allowing it to climb in a very narrow flight envelope with just a few kt between stall and limiting Mach number. On the high speed side, ultimately it is aerodynamic heating that limits things, for the airframe structure and particularly for air-breathing engines. Scram jets help here, but they are fiendishly difficult to get right. Keeping combustion going in supersonic airflow is really hard to do! Ultimately we might see aircraft that can sustain Mach 4, or possibly Mach 5, but much above that is highly unlikely. As for altitude, 100,000 ft is really the limit for conventional aircraft. Much above that and you need reaction control systems because control surfaces don’t work. And or course, at 63,000 ft is the Armstrong limit, above which you have to wear a pressure suit to survive, and even before then you need pressure breathing for oxygen if the aircraft pressurisation fails. That’s why Concorde had such small windows, and also why even the most advanced business jets don’t fly above 55,000 ft. You have to ensure they can get down to 15,000 ft in the event of cabin depressurisation, before the passengers die of oxygen starvation.

[@markewing10]

Small correction: engines don’t push against the air, they push air backwards in order to move forwards. Like sitting in a canoe and throwing a rock moves the canoe in the opposite direction rather than sitting in a canoe and pushing off the dock.

[@LeoH3L1]

Small pedantic actual correction: They do push against the air, otherwise they'd not be able to push the air backwards, that's how action-reaction works...

[@funnydog7133]

a ratio of the thrust from a turbine engine comes from both the spinning of the turbine (like a propeller) and from the velocity of the exhaust created by combustion. the extremes of either of these would be a propeller (some propeller aircraft DO get some thrust from exhaust but 99% of it is by pushing against the air with a propeller) and a rocket engine, where all of the thrust comes from the exhaust velocity

[@markewing10]

@@LeoH3L1 Sorry, i believe you aren’t correct. The air that’s being pushed backwards is the jet exhaust. That’s the action. The plane moving forward is the reaction. If what you said is true, rockets wouldn’t work in space. Maybe I’m misunderstanding you? Edit: maybe I worded my post badly. Props (and jets) push the air backwards to provide thrust. That’s the action/reaction. The air or exhaust hitting the air behind the engines do not affect the thrust. The exhaust doesn’t have to push against anything because it is the reaction mass. Hope I worded it right this time 😊

[@AndreSomers]

The story about the Perlan project is actually quite fascinating. I heard a lecture on it once. It took a lot of effort and some very special meteorological conditions to reach these insane altitudes. Enough stuff there for a whole separate video…

[@gregkail4348]

Please 🙏

[@wesleycardinal8869]

I would love to see a video on the Perlan project, it deserves more attention.

[@cf453]

They have a great website if anyone is interested.

[@SkyChaserCom]

Even the Perlan project sailplane was designed to deal with avoiding high-speed / transonic-Mach buffeting with a true airspeed at 90,000 feet expected to be nearly 450 MPH, while indicated airspeed was only 64 MPH (only 3% of the atmospheric density at sea level exists at the near ceiling of the Perlan glider).

[@michaelderflinger5002]

Did Scott mentieon the altitude Perlan2 got to? It is also remarkable, that this glider design would be able to fly in martian atmosphere. But landing at those high true air speed could be a challenge.

[@papageo79]

Watching the video at around 06:40 I remembered that that propeller in front of the plane is actually a fan. It keeps the pilot cool. If it stops you can actually see the pilot sweating..

[@jaydonbooth4042]

Really liking the additional airplane videos you've been doing since going for your private pilot's license Scott. Gives me some more appreciation for them and for the engineering challenge of flying in general.

[@dl6519]

I recall reading about U-2 pilots making a gentle turn and the inside wing is in stall buffet while the outside wing is in Mach buffet. Insane!!

[@bamascubaman]

The A-12 at Battleship Park in Mobile relatively briefly had a sign stating that that particular aircraft had been an altitude in excess of 100'k, 108 IIRC. The next time I visited, the sign had been changed, with no reference to the altitude. When I inquired, the guy only said that they had been "asked" to change it.

[@Aeronaut1975]

if I remember correctly, "coffin corner" on the U2 is around 6 knots. In other words, there's a 6 knot difference between stalling and falling out of the sky or ripping the wings off.

[@robertbutsch1802]

At cruise the U2 must be flown by autopilot as a human pilot would have a lot of trouble keeping the airplane in this narrow speed corridor.

[@BogeyTheBear]

Early model U-2s had that margin. In the later versions they expanded it to 20 knots.

[@wally7856]

All you had to do in that "coffin corner" was initiate turn and you could do both at the same time. Inner wing stalling and outer wing over speeding.

[@Chriva]

"The science of getting really high". I have a friend that does that. It usually ends in an empty fridge lol

[@morecowbell2611]

dammit he changed the title!

[@arandomcommenter412]

@@morecowbell2611 literally 1984

[@Valery0p5]

@@morecowbell2611 it's in the thumbnail

[@Powertampa]

All these squares make a circle

[@Fish-ub3wn]

I'm doing a scientific experiment on the said subject. cheers.

[@AccAkut1987]

An aircraft that I sorta missed in this overview is the Grob G 850 Strato 2C , an experimental research aircraft build for Germany's DLR. It had a really unusual engine setup, using Teledyne piston engines that were pressure fed by turbine sections of PW127 turboprop jet engines. Current altitude record for piston powered flight at 18,552 m (60,866 ft). It's a real oddball that sadly did not have a long career, and now stands on the manufacturers airfield.

[@12pentaborane]

That's an insane airplane, it uses the regional turboprop engines as turbochargers for piston engines.

[@gasdive]

I was expecting it would get a mention.

[@PsRohrbaugh]

The jet engine evolved from turbochargers on WWII aircraft. At a certain point the scientists realized "wouldn't it be better if we just got rid of the piston engine completely?"

[@gasdive]

@@PsRohrbaugh long before the second World War.

[@aerodyneservices]

But it birthed the Grob G520 Egrett, one of which towed the Perlan II to 47,000 feet in 2019.

[@idanceforpennies281]

This is one of the best expositions of high-altitude flight I have ever heard. You even covered the fact that Mach number is the critical factor above 25,000ft.

[@goatflieg]

One of the very rare times, as a pilot, that I already knew most of what you were explaining and was waiting for you to get to the good stuff.

[@blackout19]

I thought the U-2 was based on the F-104 too, but that was an early prototype, the CL-282. For the U-2 they threw out everything F-104 based. Kelly Johnson was quoted as saying the only thing left over from the 104 was the rudder pedals. Super interesting rabbit hole to go down! Thx for the content, amazing as always.

[@simongeard4824]

It's certainly hard to imagine two aircraft more different in concept than the F-104 and the U-2... one a missile with only token wings, the other a near-glider with giant wings. There's a familiarity about the fuselage though, which may have translated through the design...

[@phmwu7368]

Test pilot Tony Levier mentioned he went from flying the Lockheed with smallest wings to the Lockheed with the biggest wings !

[@PetesGuide]

The U-2 fuselage was from the F-104, but the plane the other guy was talking about was the Martin RB-57D Canberra, a stretched-wing English Electric Canberra, as a stopgap while the U-2 was being developed. It’s wings were lengthened again, and NASA still flies two.

[@jerrymiller276]

My wife and i are currently staying on the 10th floor in a resort at North Myrtle Beach. I've been watching the scene for a couple of days and there are several navy ships of various sizes on the scene. Today I've been watching off and on through binoculars and there are also two CH-53 Stallion variants flying very slowly at a low enough altitude to kick up visible spray, obviously "mowing the lawn". I guess they are determined to get every fragment of the balloon's instrument package possible, no matter how long it takes. One of them just now flew in to Grand Strand Airport, (CRE) right behind us and landed. The process has been both interesting and boring to watch.

[@jerrymiller276]

The other one just came in. I guess it is lunch time for the aircrew and the helicopters. The first one was gray and the second green. I guess all the services want a piece of the action.

[@onenerdarmy]

@@jerrymiller276 it's good peacetime SAR and the like practice.

[@beachcomber2008]

Boobytraps, anthrax spores, radioactive shit. You have to be _more_ paranoid to escape the ministrations of a paranoiac.

[@buckstarchaser2376]

Should only take a couple of weeks before they drop it for the new current thing, or just wrap it up with a smear and encourage everyone to move on to the next current thing.

[@c6q3a24]

@@buckstarchaser2376 These constant "UFOs" are more likely just a distraction. For example the enormous chemical spill and "controlled" chemical fire from a derailed train in Ohio.

[@marsgal42]

I remember seeing James May going for a flight in a U-2 and a lot of the numbers on the flight instruments were classified until not that long ago. The altitude and climb speed schedule in the U-2 flight manual looks a lot different than the performance charts for a 172. 😎

[@JoshuaC923]

I loved that episode, great stuff

[@Ooooggggggllybooogly]

Or adam savages flight It was so cool to see how excited he was at seeing the earth curve below him

[@MIG29SUU27]

I believe I may have taken part in the highest air-to-air 'kill". During my exchange tour from the Air Force to Navy Test & Evaluation Squadron Four (VX4) I was part of a detachment of three F-14s which flew from Eglin AFB (my previous home base). The purpose of this deployment was to test the then new AIM-54C Phoenix missile which was undergoing operational testing. The target for this test was an AQM-81A Firebolt which was undergoing development to meet an Air Force requirement for a high-altitude, high-speed aerial target. For our intercept the Firebolt was launched from the vicinity of MacDill AFB and was at 97,000 ft. and Mach 3 over the Gulf of Mexico. We used three F-14s to ensure that at least one of us would have an opportunity to launch a Phoenix (I was designated at the number #2 shooter). We climbed to 40,000 ft. and GCI provided us information on the target at 140 nm. We accelerated to Mach 1.5. The lead F-14 got a radar track at 90 nm. (two minute from launch) and we started our pull-up at approximately 65 nm. with a missile launch at approximately 40 nm. When the AIM-54 launched we were topping out at 50,000 ft. and the target was still almost 50,000 ft. above us which was a distance of 8 nm vertically (this was the highest I had been in a F-14)

[@MIG29SUU27]

@@mcs699 I commanded the 6513th Test Squadron - The Red Hats

[@mikeyKnows_]

What's the highest an F14 has ever gone? It makes me wonder if at those elevations the wings were spread out or tucked in.

[@MIG29SUU27]

@@mikeyKnows_ If I remember correctly the service ceiling for the F-14A was 55,000 ft. The wing sweep on the F-14 in automatic was positioned by the Central Air Data Computer. At 50,000 ft the level flight speed in military power was such that the wings would be programed fully forward (20 deg.)

[@JG-dx5wi]

@@mikeyKnows_ I've heard that the F-14 has been over 70,000 ft at mach 2.5 via some of the early F-14A pilots

[@potatopilot16]

As a pilot this video brings me joy. 1. Because my flight instructors across all my certificates taught me well clearly! 2. I can fully understand and comprehend all of the info in this video!!!!

[@everTriumph]

There were rumours an EE Lightning zoomed up to 85,000 feet. This shot past and was observed by a U2 at that time. The maximum heights of some of the bombers of the sixties, Canberra. Vulcan, Victor was set by human factors, cold and more importantly the oxygen supply specs. A bomber designed to cruise at 50K feet plus with maybe 10 ton payload can obviously climb higher with a zero bomb load. Teddy Petter designed a high aspect winged high altitude fighter in WW2, the Welkin. The problems he encountered persuaded him to design a high speed high altitude bomber, the Canberra, with a low aspect high area wing. The US stretched the concept with bigger wings and engines as a precursor to the U2.

[@attilavs2]

The Lightning really is an impressive plane, it's actually plausible

[@TessellationRow]

It sounds reasonable. The F-15 zoomed over 100,000ft

[@monsieurchevrebois9811]

@@attilavs2 It happened close to Singapore where the tropopause was particularly high and cold.

[@peetky8645]

could glsdb be launched from a balloon at 80K feet and if it were, what would it range be?

[@afischer8327]

I have heard this also. EE Lightning doing a Mach climb, more or less vertical on reheat (afterburners), the engines would cut out, and then it's just ballistics. Thin atmosphere, control surfaces barely functioning, dark sky and stars above (in daytime), Earth curvature visible, then descending the ballistic curve, into the atmosphere, control resumed, all fine. Several aircraft have done similar, although not all of of them retained control at over 80,000ft. F-104 (tumbled around and flipped until it regained some air), MiG-25, probably MiG-31, and I wouldn't be surprised if the Su-27 and its relatives have tried similarly, although the MiG-25 family would be my favourite, currently, for a Mach climb to about 90,000ft. They're not going to tell us about this. Launching missiles from a plane in a ballistic Mach climb to hit a satellite - it's been done, but I'm not sure I'd volunteer. I salute the pilots.

[@bobstovall9570]

I don't recall ever seeing more actionable information packed into a shorter presentation that this, Scott. Very well done, Sir.

[@1KJRoberts]

Gosh, Scott, I think this episode was one of your most interesting and informative to date. Good stuff!

[@prsearls]

As an old, retired corporate jet pilot, let me compliment you on your excellent explanations. You nailed it. Fly Safe!

[@jonwatkins254]

Most informative video. A high performance fighter can zoom climb above the altitude that aerodynamic control is effective and become ballistic. Reaction controls become necessary to maintain correct angle of attack, yaw and roll during the ballistic portion of the flight.

[@rocketology1105]

I love the SR-71 footage sporting the LASRE linear aerospike test! Perhaps an upcoming video on that?

[@paulgracey4697]

Nice summary and quite complete but you missed one. NASA's WB-57. It is a design that pre-dates the U-2. A licensed version of the English Electric Canberra bomber, I watched it sampling the exhaust plume of the Delta Rocket carrying the LandSat 7 to orbit when I was part of the group invited for the launch. It was atypical for it to be such a gorgeous day at Vandenberg as you are aware. On the bus going back to work at Santa Barbara Research Co.a co-worker noticed the aircraft and asked aloud about how high it was. I remembered that I had read up on it, and told him its "party trick" was its ability to exceed 60,000 ft.

[@scottmanley]

I actually have a completely separate video about the WB-57 in the works.

[@simongeard4824]

@@scottmanley Looking forward to it, since they're a pretty cool if largely uncelebrated plane...

[@mytech6779]

F-104 starfighters had zoom climbed over 100k feet before 1960. A later variant with a small rocket booster and managed 119k Fun to know mach 3.3 at 80k is equivalent to less than 400 knots at sealevel as far as aerodynamic forces go.

[@Arturo-lapaz]

That was Chuck Jaeger and on the return down he could not recover the yaw rotation, not the same as a spin, the added thruster could not stop the 'gyration' , stable rotation about the axis of maximum moment of inertia. He landed, bruised on the parachute, after a high altitude ejection , down as the early F-104 all did.

[@JonathanStCloud-yo5oq]

Yes and no. As you climb your Vne decreases because your true airspeed is higher than indicated. Ignore and you could meet Mr. Flutter

[@Arturo-lapaz]

@@JonathanStCloud-yo5oqRight. Those are 2 different effects, VNE is a force limit due to dynamic pressure q=½ rho V² Flutter is resonance of the flexibility of the structure inter acting with periodic vortex shedding phase shift until the vibration mode becomes unstable, the relevant shedding frequency is given by the struhal number f × d ÷ V V= TAS 1/sec × m ÷(m/sec) independent of density

[@JonathanStCloud-yo5oq]

@@Arturo-lapaz And right you are. I was merely trying, unskillfully, to convey that flutter is based on true airspeed, not indicated. Thank you for the math

[@Arturo-lapaz]

@@JonathanStCloud-yo5oq Your statement is correct. And the Vne , the redline is not sufficient to avoid flutter. Normally there is a margin in the redline to account for this, at lower altitude. By the way you can easily determine TAS by multiplication of CAS (~IAS) with RDR, (Root of Density Ratio) altitude (ft) RDR 18000 1.33 15000 1.27 12000 1.200 9000 1.15 6000 1.10 3000 1.05 0 1.00 of course this is valid if the out side temperature deviates little from the standard SL 15C 15°C - 2°C per 1000 ft ( defined : 15° - 6.5 °C per 1000 meter)

[@arwo1143]

The fact the USAF decided to so casually prove that they can beat the official service ceiling of their aircraft by 20% means that it can probably go a lot higher

[@randomguyinanglider4090]

Finally someone talks abaut sailplanes! The power of nature is often underrestimated. The pearland 2 wing is actually an modified version of an dg505,which is an farely standart glider when it comes to performance.

[@tlniec]

I had never considered the speed difference induced by a simple turn maneuver causing one wing to exceed its Mach limit (and potentially the other wing to simultaneously drop below its stall limit)... coffin corner, indeed.

[@MikeNelson1953]

At 1:59 Scott said " engines which push against the atmosphere". I'm sure he knows better. Propellers and turbines derive their thrust through the reaction to the acceleration of mass (Newton's Third Law). They don't push against the atmosphere any more than a rocket engine does, which is practically zero. He repeated the "push against the air" phrase two more times before the end.

[@nesquick84]

Thank you! I'm surprised more people aren't commenting this

[@andystopps]

Absolutely. I found it a bit hard to concentrate on the rest after that.

[@paulbrooks4395]

Other high altitude compensations are low bypass engines, ramjets, and eventually scramjets. Higher bypass engines lose effectiveness more quickly at altitude. The SR-71 did go above 85k, and it was more than capable of it. Due to its speed, ramjet, and lifting body it was well designed for those altitudes.

[@MeAndMyRoyalEnfield]

Corporate jet pilot here. Andrew at Rocket Ranch Boca Chica TX shared this with me and he had questions and an interesting conversation ensued about the characteristics of sound, speed of sound, air density, humidity, altitude. He records sounds at a high level and was so interesting to listen to where he comes from technically. I love all the interactions that evolve from the vastly different people who are drawn like moths to a flame that is SpaceX. Thank you for this excellent video and the conversation it created. You do great work.

[@JZ909]

I remember way back when this channel was about exploration in Eve Online. I too have moved on from that time in my life, but the "Fly safe" always brings me back.

[@sorover111]

Scott, I love to watch you going through the “aha” moments in flight training, and these videos on aerodynamic fundamentals. Also, having known a lot of pilots, instructors, examiners, etc.. I think you’ve got the perfect disposition / demeanor for flying.. Namely you’re a monumental skeptic .. and that’s a life-saving characteristic in flying. 😊 Be safe ! 💸

[@kenoliver8913]

They say that you should fly with the attitude that all aricraft mantenace crews, air traffic controllers and your airline bosses are intent on killing you ...

[@tambolianmap]

I was in the US Navy from 1961 to 1966 as an Aviation Tech. We talk to one another about what we hear over the radio. One tech formally stationed in Japan relates this story while checking the radio and heard this transmission - permission to come down to 100,000 ft!

[@everettputerbaugh3996]

I read where the speed limit of the SR-71 was the thermal limit of the air-frame. Even titanium gets soft when cooked to 800 degrees C. Mach 3.1 was deemed safe, while 3.4 was reached in emergencies.

[@hisheighnessthesupremebeing]

I was told it was the engine air INLET temperature that was the limiting factor... it's crazy that it's the temperature of the air being pressed into the front/cone of the engine and that air at that altitude (if I remember correctly) is -30 to -50c before being slowed down and heatet up by the cone ... And I remember the limiting number 427°C .. 427 because it's the size of the V8 in the legendary Shelby AC Cobra 427 (427 in cui of course).. and Celcius wich was odd for an American aircraft ... But apparently they used the metric system when designing the SR71

[@ue4770]

Great Video, Scott! I only disagree on one thing: although helicopters use engine power to directly drive their rotors, they don’t use engine thrust to defy gravity, but simply to move their rotor blades through the air, which are pretty comparable to airplane wings in the way the generate lift: an aerodynamic surface that moves through the air (or call it ‚fluent‘ to also cover Mars helicopters) and generates lift this way. The same limits of stall, flutter and Mach number apply as to a conventional fixed wing.

[@Bubbydid]

Good description of coffin corner - to elaborate on the last piece of it, the idea is the low speed buffet near the stall and the high speed buffet from high mach number can coincide, meaning you don't know whether you're going too fast or too slow.

[@wally7856]

If you make a turn in coffin corner you can do both! Outside wing too fast and inside wing too slow simultaneously!

[@Steven-p4j]

@@wally7856 sounds cool for tearing off wings or for entering a flat spin.

[@wally7856]

@@Steven-p4j The Sr-71 flight rules said they had to drop 2,000 feet (from cruise) to make a course correction. They flew that plane so close to coffin corner they could reach out and touch the walls.

[@neovo903]

Well, Reynolds number is very important. This can influence the aerofoil choice and wing aspect ratio. Picking the correct engine and the ramps for flight at that height is important.

[@neovo903]

Bernoulli's principle and the Coanda effect (If supersonic)

[@neovo903]

If you can fly fast at altitude, you can use ramps or a shock cone to slow down the air and compress it for the engine to ingest, this could get more performance from the engine at high altitude, especially considering you'd be increasing the difference between V9 and V0 which would increase thrust.

[@neovo903]

As an aircraft passes into supersonic speeds, the centre of pressure changes with is something worth noting. Concorde countered this by changing the centre of mass by pumping fuel to different tanks, thus keeping the aircraft under control.

[@neovo903]

The EE Lightning is a good example of massive power and zoom climbing too

[@neovo903]

The EE Lightning's max altitude is still classified if I remember correctly

[@planespeaking]

Solar powered HAPS gliders are being discussed again to provide communication with lower lag than satellite internet like starlink etc. Really enjoyed this video, thanks

[@herbertkeithmiller]

Oh in airplanes, I'll watch anyway because anything Scott does is good.

[@room1814]

A other factor that comes into play with Max Operating Altitude and airliners: rapid decompression and emergency descent. A few years ago 3 of us were given the opportunity to visit 3 on 1 with the 747 Boeing Chief Test Pilot. Our company had just taken delivery of some 747-8s and Boeing wanted feedback. So it came up in the conversation that the -8 MOA was lower than the -400. And the answer we got was “Oh yeah, both can go lots higher. The limitation is there based upon the ability to perform an emergency descent and get to 14,000 feet in a defined time. (90 seconds is what I remember) Seems the -400 can get down faster than a -8, hence the 45,100 vs 43,100 numbers.

[@popguy2815]

The SR71 is just a fascinating study of what you can build with no budget limits. Originally it was a design for an interceptor but even the Imperial air force chocked on the cost of building hundreds of them.

[@SnakebitSTI]

The SR-71 and its predecessor the A-12 were both designed for reconnaissance. The YF-12, an A-12 variant, was designed to be an interceptor, and that's the program that was canceled.

[@dddd6606]

Oh, a rare Australian intro!

[@fantabuloussnuffaluffagus]

The Lockheed F-104 Starfighter introduced in 1958 Was running level intercepts on U2s at 70,000 ft in the 1960s. The highest altitude reached by an F-104 was over 100,000 ft. An intercept flown at 65,000 ft has been possible since at least 1960.

[@richardvernon317]

F-104A could reach 93,000 feet in 1958 (broke the official world time to height records doing it). F4H1 (Prototype F-4A Phantom) managed to get to 98,500 feet (breaking the same records)) in 1961. In fact most Mach 2 capable aircraft can get well above 60,000 feet, The only reason that they don't do it day to day is because the pilots are not wearing full pressure suits which you need to wear if you want to survive any form of cockpit pressurization failure about 60,000 feet.

[@fantabuloussnuffaluffagus]

@@richardvernon317 A Navy F4H1 went to 98,500 on December 6 1958. On December 14 1958 Capt. Joe Jordan got in an Air Force F-104A and reset the absolute altitude record at 103,395.5 feet. While he was on the way up he hit M2.36 and set a time to climb record for 30,000m. The Phantom's record stood for 8 days. The Starfighter gets a lot of flak for the German experience, but DAMN, what a performer. Check out the Air Boyd Video "Joe Jordan's F-104 Record Altitude Flight (1959)"

[@Gorvaunity]

Most high performance private jets actually get to fly higher because of two factors, first is that their payload is usually quite low (difference from an airliner which will be quite loaded for the airline to make money), and second is that VIPs usually prioritize a smooth flight, and getting to 50.000ft is a great way to avoid weather. Airliners do have a VNE, which is a factor up until about 25/30K feet, when it will cross the MMO (max operating mach) which will be the operating limit. On most modern airliners, you get to climb enroute as you burn fuel down, and when climbing near the ceiling you can actually see the coffin corner on your airspeed indication, as it shows both stall at lower speeds and MMO at higher speeds. Thanks for your videos!

[@peteconrad2077]

One other factor. Their cabins are sometimes stressed fir higher Dp.

[@AllanFolm]

Have you read Benjamin Rich "Skunk Works"? He was an engineer who was tapped to work on the U2, stayed on to work on the SR71, and eventually became head of Skunk Works, where he amongst other projects fathered the F117 Nighthawk and the Stealth Ship "Sea Shadow".

[@Zakster90]

I sat here for 17 minutes thinking he was going to show us how to make LSD or something to get really high, I feel cheated

[@KubaSzymanowski]

The video is out for only 5 minutes

[@i-_-am-_-g1467]

We'd like to keep our brains and sanity thanks. Also the Title has broken English in it

[@i-_-am-_-g1467]

Also you say you sat here for 17 minutes when the video has only been out for 9 minutes? Keep taking your lsd freako liar

[@Bibibosh]

Recipe to make LSD!!!! Mix the banana juice with 3 Lego people in an egg basket. Take a cricket bat and touch the apple while eating the marshmallow. Microwave all the ingredients in a soggy Microsoft word document, talk to your mother's father's sister about earthworms, and let it cool down for about 30 phytoplanktons or 40pps if you live upstairs! Then you will have some LSD. That's how I make my own high substance! The effects should last about 4-6 hours. Just don't double dose unless you're sure and done this before! Good luck any questions just ask me! I have done LSD 2 times now and I'm 34 :)

[@josipbroztito6763]

@@Bibibosh I thought the recipe for LSD was to put a dyslexic Mormon in the oven at 420 degrees for 69 minutes and collect the juices?

[@samsonsoturian6013]

The insane speeds of the SR-71 is why is was so expensive. Titanium was used in order to survive higher air friction while staying lightweight, and this was difficult to mine, refine, and machine. Also they were consuming half the world's supply, so they had to set up a shell company to buy some from the Soviets.

[@Genius_at_Work]

"Half the World's Supply" sounds a bit exagerated given that the Soviet Union built Nuclear Submarines with Hulls Made of Titanium

[@afoxwithahat7846]

Air compression, Samson, Titanium was used to survive hypersonic air compression, which heats up the shell. It's twice as hard to work with because at high temperatures the Titanium oxides and loses the majority of its properties.

[@TheBackyardChemist]

Mining is really not too bad, titanium dioxide is a common mineral and a byproduct of aluminium mining. Turning that white powder into usable metal is quite challenging and expensive.

[@GreenBlueWalkthrough]

And it's getting cheaper ever day... look at the F-35 and how much that guy ujses of titaum compared to the F-15 for example.

[@GreenBlueWalkthrough]

@@TheBackyardChemist And having havinnng the machines to shape the mmetal because of the reasons you want it in the first place.

[@markkosten]

The XB-70 was rated at 77.000 ft but the prototypes, especially number 1, had many issues that limited performance. If it was properly developed into production I am sure it would have gone much higher, perhaps matching the SR-71/A12.

[@davewitter6565]

I enjoyed the basis principals and the clear explanations. I am amazed the Concorde could do what it did. I view it as the European Moon Shot.

[@honkhonk8009]

Scott Manley the only dude that can take a crazy event like this, and turn it into some KSP discussion lol. I love this guys channel. Always can count on him to make my day lol

[@nekomasteryoutube3232]

Man this was quite the interesting video, got to learn some new terms/concepts like Zoom climb, which sounds pretty cool to get an aircraft up to higher altitudes quickly.

[@MattH-wg7ou]

Zooming can be quite dangerous. If you zoom too high your airspeed can get low enough, and the air is too thin, to keep the engines going and you can have compressor stalls. Losing both engines (and the flight controls they power) at that alt can be unrecoverable. I think Yeager bailed out of an F104 because of this once but I may be mistaken.

[@nekomasteryoutube3232]

@@MattH-wg7ou Yeah I can imagine, I mean while your trading energies around for altitude, your still pushing the aircraft beyond its limits if your going well above its flight ceiling. though I did see on wikipedia that jet fighters can do this as a tactic to out run missiles. TBH I'd rather take the risk of either breaking my jet (engines) or stalling than have a missile hit me (which it doesnt need to actually HIT you , just needs to get close enough to go off as some use shrapnel or some other fragmentation like balls or something as their weapon to damage aircraft)

[@thomasgoodwin2648]

OK odd added value story, I learned about Zoom Climbs playing "Chuck Yeager's Advanced Flight Trainer" for C64 back in the late 80's early 90's ish. The game was chunky and hard to control, but with enough persistence, you really did learn about test piloting skills. How did those numbers get in the flight manual to begin with? Someone had to actually flight test the plane to the limit to find out (except for perhaps the 'Do Not Exceed' speed. Ripping the wings off of your perfectly good vehicle == BAD). Test piloting is mostly mundane and boring. For example: determining the best climb airspeed is done simply by a series of tests that just put the aircraft into a specific configuration to achieve the desired airspeed and timing how long it takes to climb through a given altitude range. Wash, Rinse, Repeat. Dull, Dull, Dull. The little bit left over would make for a great diapers ad. Full props to the Test Pilots living and dead. The required skill set is unique. Daredevil's need not apply.

[@peetky8645]

@@MattH-wg7ou mentour pilot did a video on this where two airline pilots took a small airliner above its service ceiling and stalled the engines. the heat in the engines then melted them and they could not restart and crashed. they were too embarrassed to admit to the tower that they had lost both engines and were not able to get to a strip by the time they declared an emergency

[@Chris_In_Texas]

The Mach 2.1 F-104 Starfighter baby! 31.6Km (just under 104,000 feet) Such a cool plane! I have been to 51,120 feet in a LearJet back in the 80's. Was cool to be that high back then as there wasn't many private jets going that high. Then the other way I have been down to -131' in altitude in a sub! 😁👍 Keep up the good work.

[@brandonho5266]

Where you might see a thumbnail, I see 4 Ace Combat Covers

[@joshuabessire9169]

I seriously thought that, too.

[@clavo3352]

"Fly Safe!" yeah but at what altitude and speed? yeah, yeah I know; "it depends on what your flying!" Great video; super well explained! I want Scott to adopt me!

[@Mike_Costello]

You literally wanted to say "the operating manual for my Space Craft" 6:25 You almost said the quiet part out loud. Great video. Your videos are more interesting now you are flying yourself too. Well done.

[@roysmith5902]

I'll push back on your statement at 2:10 about helicopters not having wings. They do indeed have wings. Rotating ones. But a rotor blade generates lift in exactly the same way as a fixed wing does; airflow at some angle of attack over an airfoil. Hence the classification as "rotary wing" vs "fixed wing".

[@scottmanley]

Sure, but then you get into arguing that the fan blades in a jet engine are also wings.

[@spacexrocks1041]

@@scottmanley My apologies Scott - I know it's rude to question the host - but the rotating wings in a helicopter provide lift, whereas fan blades improve thrust by compressing air into an engine. Aren't lift & thrust different processes? If so, I'm not sure that anyone could reasonably argue that fan blades are wings.

[@another3997]

@@spacexrocks1041 Surely the principles are broadly the same? A set of rotating blades move air in a particular direction. How that thrust is used is what differentiates them.

[@spacexrocks1041]

@@another3997 They both move air. I just think it's for different processes. Lift is different than thrust. If you point a set of rotating fan blades straight down, without the engine running, they just pull in air, like a vacuum cleaner. It moves air, but it doesn't provide lift.

[@justarandomname420]

The F22's glorious air combat kills make the cost well worth it...

[@cherriberri8373]

@@Nick-mt4wk truly. If theres one thing more annoying than overly expensive military gear, its the people making the same stupid jokes/comments about it

[@nubcake67]

A jet so unbelievably advanced that it has almost obsoleted itself without a single enemy engagement.

[@Anvilshock]

@@cherriberri8373 Reminds me of Americans stalwartly defending inches with that same old clichéed Moon landing line. Sure, it was an impressive feat in numbers, but not only was it a political dick-waving publicity stunt disproportionately overfunded (for a "science" project, wink-wink) to one-up the Soviets, it was also mostly metric except where jobs had to be handed out to contractors. Even the capsule spoke metric, yet had to spend valuable computation cycles to display everything in muppet units because the pilots were all trained Navy who didn't know metric if they got shot with it.

[@GabrielAKAFinn]

@@cherriberri8373 Cry about it

[@twotrackjack2260]

🎈🎈🎈🎈

[@peteranderson037]

0:35 Shooting a satellite out of orbit doesn't count as an air-to-air kill because in space no one can hear you scream.

[@joyl7842]

I remember something about a F-104 Starfighter flying above 100.000 feet, thanks to a kind of parabolic maneuver which allowed the very high altitude to be reached.

[@nereanim]

The HOTOL which was a SSTO prototype sadly vaporware had an interesting take: Use liquid H2 to liquefy athmospheric air then extract the O2 to add to its O2 reserves... thus in theory exploiting some of the air for its benefit even if rocket powered.

[@jonathan_60503]

1:24 - hmm, kind of borderline whether you could say a helicopter stayed aloft just from its engine when it's got those big rotating aerodynamic surfaces -- the blades of its rotor(s) -- which kind of are a type of wing. The NASA Lunar Landing Research Vehicle (aka flying bedstead) would seem a better, if not so well known, example of flying from pure engine power.

[@scottmanley]

You are absolutely correct, moreover when it’s moving forward through the air those blades generate lift like a wing.

[@kunjukunjunil1481]

Yeah, Helicopters are "Rotary Wing" Aircrafts.

[@another3997]

@@scottmanley With rotary aircraft, do the retreating blades produce less lift than the advancing ones in forward flight? I know the mechanics of typical helicopters are complicated and inefficient in comparison to typical fixed wing aircraft.

[@AthAthanasius]

What? No-one else commenting on the inverted intro animation ?

[@tpaine666]

Jet engines do not push against the air anymore than rocket engines do... unless you are talking about turbofan engines. Perhaps a bit more clarity would be useful here... Love your stuff... keep it coming!

[@richgeorge4368]

Oh Scott. How I love your videos. Beautifully tailored to those of us who didn’t get beyond A level science. Fantastically simplified, pitched and delivered. Thank you. I find this fascinating.

[@privateer0561]

The SR-71 made sea level power at 85,000 feet despite the thin air due to its Pratt & Whitney J58 turboramjet engines. The A-12 versions flew at 95,000 feet at Mach 3.35

[@maxtorque2277]

The Sr-71 is clearly the master of the "go fast by having a LOT of power" segment, but what is rather interesting is where all that power comes from. Thanks to it's clever inlets being able to leverage the incoming dynamic pressure and turn that into static pressure, at a M3.0 cruise the inlet is actually providing 70% or more of the total forward thrust. ie the higher static pressure behind the inlet tries to actually push it forwards out of the airframe and as a result actually puses the thing along! Of course, ultimately the energy is all coming from the fuel being burnt in the engine, and the engine must be running and removing that high pressure air from behind the inlet for this trick to work, however this way of seemingly getting something for nothing can be somewhat difficult to get ones head around initally 🙂 These high dynamic range inlets (and the classic long delta wing drag characteristics) are what enabled both the Sr-71 and Concorde to achieve lower fuel consumption the faster they went, which is also extremely counter intuitive. The fact all this was worked out in the late 1950's and early 1960's with very basic analysis, calculation and test equipment is truely mind boggling (to someone that these days routinely records nearly a thousand channels of data at >1KHz on a simple passenger car development test.....)

[@LowVoltage_FPV]

Jet engines don't "push against the air" any more then rocket engines do. The actual mechanism is action and re-action. The air being forced backwards has mass and pushing it backwards results in an equal and opposite reaction.

[@scottmanley]

The turbofan disc pushes on the air, the air in core is pushed out that back. It’s pushing air.

[@WanJae42]

@@scottmanley It is pumping air mass, yes. It's not pushing 'against' the air. Physics classes go to some length to drill the 'against' mentality out of students. We know what you meant, but it's an important distinction.

[@ryanspence5831]

@@WanJae42 it's pushing against the air as much as you push against the water when you swim--you're making a distinction without a difference I think

[@WanJae42]

@@ryanspence5831 No, it's really not. Jet propulsion works in a vacuum (given oxidizer). This is a physics fundamental.

[@scottmanley]

Yeah, it works because it pushes gas out the exhaust. Equal an opposite reaction still require pushing agains the reaction mass.

[@justinodom4189]

Hey Scott! Love your videos and your deep explanations and different perspective. Can you do a deep dive on the soviet N1? Everyone compares Starship to N1 and Saturn V, but would love to know more about how it really stacks up. Thanks

[@raymobula]

Ahh, this brings be back to my Fluid-mechanics times. Loved playing with wind tunnels and pushing limits of wing designs and impellers.

[@eurybaric]

Mulatu Astatke playing and Scott Manley telling and explaining is A++

[@glauberglousger6643]

Use Balloons, if that doesn’t work, more Balloons, I miss airships though, they aren’t even that dangerous anymore

[@johndododoe1411]

For unique military missions, the danger of a hydrogen fire can be acceptable, especially without an onboard pilot. So a hydrogen airship remotely operated with hydrogen burning engines could be a useful high altitude tool. For advanced weather balloons studying high altitude winds, considerable navigation and communication electronics will be needed to accurately report back location and altitude far from the launch station. Thus when analyzing the Chinese balloon, they will need to subtract the parts that detect GPS/Baidu location and the parts that contacts available communication networks to phone home. After that, we'll know exactly what systems were included to record surface activity of interest to spy agencies. Without that subtraction, antennas to log on to Verizon Internet and send back data would confuse the intelligence.

[@ericmatthews8497]

Ok.. A glider that can reach 100,000 feet .. unpowered .. is freaking amazing.

[@MatthijsvanDuin]

Their goal is actually 90,000 feet, not 100,000, but close enough. Definitely a "whoa" moment to know that a specialized glider can get there. At that altitude they'll be flying around mach 0.4-0.5 ... in a glider.

[@xiphosura413]

I've been following the Perlan Project for a bit of time now, and it is truly impressive some of the stuff they have achieved! A suprising problem is windows and instruments fogging up due to temperature differences, I'm fascinated by the wind systems they utilise to get these records.

[@AstronAndry]

Simple: Smoke weed.

[@stevenross-watt8640]

Great video. I listened to it whilst driving my car with the phone screen off. Came across perfectly. Thanks again.

[@arlberg2006]

Glad that you mentioned "coffin corner" Was almost waiting for it before you even had mentioned it. What about the study of the CF34 engines in that CRJ flight they ferried - then melted?

[@GriffithMccarthy]

The greatest antidote to insecurity and the sense of fear is compassion it brings one back to the basis of one's inner strength

[@bryanbrewer4272]

i am sooooo high while watching this, that last bong rip put me in a new dimension.....

[@robinj.9329]

Several private Jets have been certified to fly as high as 45,000 and even 51,000 feet. And the SR-71 Flew missions as high as 80,000 or even 85,000 feet on a regular basis.

[@MaxGuides]

I feel like there’s so much that you couldn’t fit into this video…like the shockwave produced by going any exact multiple of Mach 1 preventing the pitot tube from working, briefly when crossing that threshold, is related to the ability of the supersonic intake cone of the SR71 sliding back & forth at supersonic speeds which relates to the newer mode switching engines where at some point the actual blades in the engine are getting in the way so some scramjet designs are bladeless allowing just the hypersonic air coming into the intake to compress & ignite itself…just most conventional jet engines are limited by having to slow the air dow internally to relative subsonic speeds limiting the maximum speed they can produce thrust at even without these other issues of deflecting hypersonic air away from conventional intakes. Guess this video was more about flying high than it was about flying fast though. Great stuff Scott!

[@StevePemberton2]

I can understand things happening at Mach 1, but it's surprising that exact multiples of Mach 1 do something. How does the air know that it is at a multiple of Mach 1? Calculating Mach angle (not that I fully understand it) I see that Mach 1 is 90.000 degrees, which is understandable, then Mach 2 is somehow magically 30.000 degrees. But Mach 3 is 19.471 degrees, Mach 4 is 14.478, Mach 5 is 11.537. So I guess what you are referring to doesn't have to do with Mach angle but something else.

[@leebyrd723]

Scott, I've some push-back on your "Pushing against air / Something to push against" descriptive statements.. Are not propellers and jets creating motion via the mass of air accelerated toward the rear of the aircraft via Newton's 2nd law of motion? As with rockets in a vacuum, they are not "pushing against something" (in this case atmospheric air) but instead using air as the "propelled mass" ejected out the back instead of carrying that mass with them as a rocket does. A sailboat is pushed by air. In that case the air pushes against the sail. Power transferred through a propeller pushes air, rather than having air push against it, but with regards to creating forward propulsion it does not push that air "against anything" to create a motive force. Am I missing something?

[@joshuaboudreau5258]

Absolutely love your video. As a glider pilot and plane enthusiast in general, I find your explanations "grounded" and easily understandable. Thanks, Scott.

[@colinbarnard6512]

Judging by the subject, and the erudition of the presenter, it would appear that Mr Manley's flying lessons were enjoyable and worthwhile for the student. Tha audience benefits, too. Thanks, Scott!

[@wxdave5448]

Very nicely done. Like Scott, I’m a student pilot but also an enthusiast of all things aircraft and space. I have a special love of the SR-71 too.

[@justincase5272]

The McDonnell Douglas F-4 Phantom II had a service ceiling of 60,000, but I recall reports where it flew much higher, including Sustained Altitude of 66,443.8 ft set on 5 December 1961 and an Altitude - Top Flight of 98,557 ft set on 6 December 1959. As the McDonnell Douglas F-15 Eagle and the Lockheed Martin F-22 Raptor have the same service ceiling of 65,000, I suspect they have similar high-altitude capabilities. Good presentation on the performance considerations!

[@frankgulla2335]

A terrific video about high altitude and "high" speed flight. Thanks, Scott.

[@alexanderzintler]

6:28 "the operating handbook for my sp.. plane" I appreciate Scott referring to the plane he's flying as a spaceship.

[@manythingslefttobuild]

Great video Scott, Chuck Yeager's F-104 high altitude flight and crash would have fit into this one nicely.

[@andrewnaylor3965]

That was one of your greatest KZbin videos, (un rocket related), so many answers to soooo many questions Thank you. Explained for the common man/woman to understand

[@royschering1140]

The RB-57F model of the Canberra has a service ceiling of over 60,000 feet, a wingspan greater than the U2, and has been operation since 1963 (the last 3 are run by NASA as the WB-57F). I was astounded at how large the wingspan is when I got to examine one in 1967 while I was in the US Air Force. It looked completely different from the earlier B-57 models. It still had two engines imbedded in the wings, but two more smaller jet engines were hung under the wings.

[@cobber1303]

I always come here thinking it’s a Tom Scott video but stay because you rock

[@kmcrafting4837]

My father-in-law was on a private transatlantic flight that ended up setting a new record for city - city in the late aughts. Reached an effective speed over Mach 1 in a Gulfstream due to a 200+knot tailwind. Has a framed copy of the local paper's coverage.