Boeing's Propeller 747 - The Never Built 747-500

[@lklpalka]

I met a 23yr old engineering prodigy in 1985 just hired by Boeing for this particular focus. Metallurgy and failure containment were the chief obstacles. Don't remember Boeing's ever coming to be. It looks complicated. Contra-rotating TU-95 actually operated for a while.

[@V8_screw_electric_cars]

Russia is still using them.

[@gabemissouri]

Russia is still using them lmao, every tu-95 is contra-rotating.

[@rock3tcatU233]

Sounds like a skill issue.

[@TomEarley]

Please do a video on Safran’s new “open rotor” prop fan engine, and how they plan to combat the noise issues.

[@abuBrachiosaurus]

You should make a video about the mini 747, the tiny 747 that no one wanted.

[@louierenault7344]

The 747-sp?

[@moteroargentino7944]

Let's take this plane known and bought for it's large capacity, and downsize it. Genius!

[@LarryTheTubaBoy]

I'm losing my hearing just imagining what this would sound like...

[@FoundAndExplained]

Sounds like all the comments in the 'held for review' section of my channel ;)

[@Alexanderthe_Ok]

Came here to say this. That thing would've been insane.

[@techhelpportalextras3007]

@@FoundAndExplained huh

[@moosepasshippie]

Submarines can hear the TU-95 when it flys over.

[@danielkorladis7869]

It would sound like glory.

[@riliryrimaddyvia9630]

Imagine all the memes we will get if this actually flown.

[@foxgaming76yt24]

Wdym

[@riliryrimaddyvia9630]

@@foxgaming76yt24 you know those memes

[@SceurdiaStudios]

If this actually flown, we will be used to it, so it won't look as weird as we see it now

[@foxgaming76yt24]

@@SceurdiaStudios it looks fine if you ask me, maybe just that the propfan seems very tiny.

[@SceurdiaStudios]

@@foxgaming76yt24 it's still unusual in my opinion. There's nothing wrong with that though

[@a.gordon.1385]

I'm Australian/British and move between the two a fair bit. I would only want to take one non stop flight if I were rich enough to afford first class, or the plane did Mach 3.

[@riliryrimaddyvia9630]

Anyone else imagining a A380-900 with those engines if the engines succeeded?

[@mattiavenator9931]

I was imagining the Antonov AN-225 with those engines

[@Joa_sss]

@@mattiavenator9931lol

[@bocahdongo7769]

@@mattiavenator9931 basically AN-22

[@mattiavenator9931]

@@bocahdongo7769 yes, but actually, no

[@noobplayer_23]

@@bocahdongo7769 with 6 engines

[@tjp353]

That thing would be incredibly noisy.

[@kdrapertrucker]

Its just a turbofan without a bypass duct.

[@Cal94]

Is it an open turbine, or just contra rotating props... There's plenty of contra-rotating prop aircraft in the history of flight, and what's been said of pretty much all of them, is they're incredibly loud. Certainly not ideal for commercial flight.

[@romanszwarc3288]

@@Cal94 the soviet Tu 114 would be an example

[@danielkorladis7869]

@@romanszwarc3288 and it was glorious

[@lzh4950]

@@romanszwarc3288 Or Tu-95?

[@ghostrider-be9ek]

Couple of observations - with engines that low, a minor pod strike would go from an annoyance, to immediate total engine replacement. Also, they could have easily ducted the props for reduced noise.

[@HBKILLMISSU]

Duct the props? So just a normal turbofan? :))

[@TheAmazingCowpig]

Ducting the props means you've just come up with a high-bypass turbofan. Hooray?

[@ghostrider-be9ek]

@@TheAmazingCowpig yes, the contra rotating fans would still work with a large fuel burn reduction as an advantage. The ducts would add a bit of weight, but at a tremendous decrease in sound.

[@ghostrider-be9ek]

@@HBKILLMISSU yes, the contra rotating fans would still work with a large fuel burn reduction as an advantage. The ducts would add a bit of weight, but at a tremendous decrease in sound.

[@HBKILLMISSU]

@@ghostrider-be9ek The whole point of the unducted fan was to have very large bypass ratio, which is why the propfan was so much more efficient than its ducted counterpart. I believe your proposal is essentially negating that premise: what’s the point of having a ducted unducted fan?

[@mattiavenator9931]

Concept of the Boeing 747 with propfans:"exist" Me: oh cool! Also me after 0.0002 seconds: wait, that's illegal!

[@ricardosenpai6121]

Woah, Im still not finish watching the 747X vid.

[@SirFawzar]

When I read the title and look at the thumbnail: o_O

[@Brilliance792]

1:02 that was a clean cut 😎

[@chadr2604]

I can't imagine how loud it would be. At least turbofan engines have a shroud to dampen the noise from the fan. The fan makes most of the racket.

[@Nordlicht05]

I only know this from model planes. A back mounted propeller is signifikant louder that the same prop in front.

[@tedolphbundler724]

Modern turboprops have noise Cancellation in the cabin. They are quiet.

[@LOLHAMMER45678]

@@tedolphbundler724 With this you need to worry about noise outside the cabin too. Like a Tu-95

[@tedolphbundler724]

@@LOLHAMMER45678 Why do I need to worry about noise outside the cabin? I don't live next to an airport!

[@bulcsu7044]

@@tedolphbundler724 Big contrarotating props are loud even when they pass by at 40k feet

[@TomEarley]

Do a video on GEARED turbo fan engines, the history and the future.

[@TomEarley]

@Nolan Dines where there's a gear box between the jet engine and the fan so they run and different speeds for better efficiency.

[@filledwithvariousknowledge1065]

As long as it was designed by Joe Sutter’s incredible team that created the original 747 it wouldn’t have problems except for the engines which would be the engine makers responsibility

[@GERntleMAN]

Then you clearly have no knowledge in aviation. The 747 had a lot of serious problems in the first 20 years causing numerous crashes

[@filledwithvariousknowledge2747]

@@GERntleMAN Nothing compare to the Death Cruiser 10

[@GERntleMAN]

@@filledwithvariousknowledge2747 I don't know the numbers of operational 747s and DC10 at the same time, so I can't compare them. I know the DC10 was horrible in crash statistics, but I don't know how bad in total numbers to the 747. Alas, losing a part of your roof or a fire in your insulation are really distinct faults on the 747.

[@filledwithvariousknowledge2747]

@@GERntleMAN If you go by number in service together + how much redundancies both were built with in case of problems the 747 is the much safer one

[@GERntleMAN]

@@filledwithvariousknowledge2747 Yeah, thought so. There were a crazy lot of 747s around

[@arthurkallansrud1950]

I am living in Indonesia now after retirement from the USAF. I was a aircraft mechanic for 16 years and worked on both prop and jet engine planes.I think the long range combo engine would be good but at 30-35,000 ft. not to sure it would be as good as a turbo jet engine that are on aircraft today.

[@FoundAndExplained]

No ultimately the engine makers took the learnings and used it to build the turbo fan engine

[@varadbhosale731]

This channel is seriously underrated

[@TheWizardGamez]

High-bypass: exists Ultra high bypass: HOL my beer

[@ericlotze7724]

Would it be a higher frequency noise? I personally love the low hum of P-3 Turboprops!

[@riliryrimaddyvia9630]

It's funny that I found this channel by your monorail video and started watching since then.

[@FoundAndExplained]

it was my best video on the channel for a long time... now its only got like 5,000 views? its insane

[@riliryrimaddyvia9630]

@@FoundAndExplained yea ,the progression of this channel was pretty great

[@itstomatogear6806]

Lmao

[@randomdeadpool]

For the streams you could do something like Q&A, just chating or maybe playing a game like Microsoft Flight Simulator, DCS? Maybe?

[@ralphmenta7997]

This was actually forward thinking. Most people don't realize that the newest jumbo turbo fan engines are basically turboprop engines with a cowl around them. Its a bit more complicated but they are a big ducted fan around a jet engine.

[@ellenorbjornsdottir1166]

yes

[@jpb2541]

Cursed images 😂

[@OG_Wilikers]

R/cursedcomment 😂

[@andreas3173]

@@OG_Wilikers No

[@andreas3173]

This is NOT a cursed comment

[@KayTheKaiju]

0:55 another cursed image

[@KudosK42]

This comment section emits normie energy

[@springbok4015]

The prop fan was also largely unnecessary given the expansion and development of high-bypass turbofans. Add in the extra cost of development for an engine that never took off, the noise and potential safety concerns of un contained engine failures and relaxation of ETOPS meant few wanted such an aircraft. The 747-400 would comfortably reach destinations like Johannesburg, Dubai, Los Angeles etc. Twin jets and leaning away from the hub & spoke model all took its toll. Good video!

[@stephendoherty8291]

Live stream ideas: interviews with plane manufacture future development, electric planes, carbon neutral fuel makers, nasa and EU future aviation projects (like clearskies2), supersonic jet builders, ultra longhaul trips and health, airport design,

[@FoundAndExplained]

I really want to do airport design!

[@jameslee4946]

I helped and worked in the Wind Tunnel model shop in Seattle, to build this engine, great design!

[@FoundAndExplained]

No way!

[@prohypeman]

ur production value is insane

[@kwasiadu-amankwah7578]

Is it the propellers that made the engines loud?

[@DrHarryT]

It seems that they did create a different version of this engine and it was put into wide service. This updated design put the prop in front and encased it in a cowling which reduced blade tip vortex drag and noise. This engine that is currently in service is called the Hi-Bypass Turbo Fan. CFM International currently makes LEAP-1B engines a version of this engine which is installed on the Boeing Max-8. GE manufactures a monster version of the turbo fan named "GE90" Another common Turbo Fan is the GE/Safran CFM56.

[@flythebus]

Would love to see you do a video on the 747-300 tri jet design that Boeing almost moved on as well.

[@wwt17]

At 6:44 we see the Delta 67 landing at PDX 28L-10R. I drive Marine Dr. to commute to and from work and pass PDX every day. Fun drive!

[@asfanamin1845]

Literally every airlines: i prefer jet enginges

[@RD1R]

Well hey turboprops technically have a jet.

[@thewildsimon1418]

Airlines prefer well tested systems granted the propfan was tested it wasn’t enough or long enough to seriously gain airlines attention until it was to late

[@goldy_on_pc930]

“This is what they do to the bad planes” said the 707 to the baby 747

[@ludowigocraft208]

Do some behind the scenes

[@GlamorousTitanic21]

Every day you upload is a good day!😊

[@FoundAndExplained]

Twice or three times a week :)

[@MTTT1234]

This design makes me kinda cringe, looking how close the rotating parts are to the wing. I mean, just a bit of a wobble of the thing and you are sawing off your own wing, kind of.

[@FoundAndExplained]

I couldn’t figure out how they would operate. If they stuck out beyond the back edge of the wing then the engines would be different sizes as the engines are different thicknesses

[@billymcnutt116]

The low wing of the 747 looks like the props would hit the ground. Maybe a high wing design? (Kind of like Airbus A400M or Antonov An-70)

[@auxiliarypowerunit]

@Bryan Justus bots

[@springbok4015]

@@billymcnutt116 High mounted wings wouldn’t really be suitable for this kind of application. There would likely have been enough clearance, but high AOA on the ground when landing/take off could be problematic.

[@xiaoka]

@@FoundAndExplained it would chop up the ground crew for sure.

[@DDRWakaLaka]

TURBOPROP 747 OH MY GOD I'm kind of losing my mind I love this

[@dennisthebrony2022]

If the 747X would exist today, it could be Reimagined as the 747-9X, which the 747-9X would be an ULTRA-LONG RANGE HGW version of the 747-8i, but with the same GE9X engine on the smaller 777X, but with the exact same fuselage on the 747-8, but slightly redesigned with the interior of the 777X. The 747-9X could have held the record as being The Longest Range Double Decker ever built. The 747-10X is the 747 with the upper deck EXTENDED almost the entire length of the plane, to the front of the tail, as you saw at the end of this video. The wing tips on the 747X will also fold up, just like the 777X, to ensure the LARGE double decker can fit into smaller Size-E gates. The 747X wings might've ALMOST been the same length as the A380's wings, but when folded up, have the same span as the 777-300ER. The 747-9X can seat up to 467 passengers in a 3-class configuration or up to 605 all economy, just like the 747-8. The 747-10X will seat 496-505 Passengers in a 3-class configuration, or 729 if all economy. Both variants of the 747X would've had the GE9X engines also used on the 777X.

[@Th3_Gael]

Finally, youtube makes a recommendation I've subbed to

[@FoundAndExplained]

Thanks for coming! I hope you enjoy and if you have any ideas for future videos let me know :)

[@Th3_Gael]

@@FoundAndExplained you're doing well on the video front already. Hopefully others are being recommended them too, you deserve more subs

[@glike2]

5:38 looks like a GTF very high bypass engine concept

[@EpicThe112]

If built the Airbus answer for this one is A380-800 with 4 CFM Rise Propfans on the builder plate A380-85x 5 CFM Rise engine/Leaf-X

[@portuguesnomundo]

Nice video my friend ✈️

[@Happymali10]

It kinda reminds me of a movie prop in the direction of the 'Skyfleet S570' from Casino Royale. -Take an old 747 -Stick something odd under the wings -Done

[@grahamariss2111]

The other issue is that the 747 is to big for these long runs, because these routes while long are also thin in passenger numbers, so you need something smaller that allows you to scoop up the business class passengers who will pay a premium for the convenience and speed of a single hop and then not leave you with a vast economy class section to fill up with passengers who's choice is primarily made on the basis of ticket price.

[@tulsatrash]

Man I wish you had gotten to the engine makers deciding not to go through with producing the prop fan engine sooner in the video cuz then you could have told us more about why they decided not to do it.

[@SandeepKaur-zd3wl]

The ad placement impresses me

[@ue4770]

I wonder if, besides the operational aspects mentioned in the video, there were also technical or certification aspects that were not competitive. A turbofan engine has a rugged housing that must withstand for example the loss of a fan blade. Imagine this case with a propfan: the fan blade would penetrate the fuselage or the wing, hitting and destroying structure, control system components, fuel tanks, or even injure or kill occupants. Not very desirable..

[@vermicelledecheval5219]

Well you have the same potential hazard with turboprops but I fail remembering any fateful events. BTW propfans are regaining interests - Safran is testing a new gen propfan which should be much less noisy. This tech would be a gainer against bird strikes too.

[@roberthamilton1301]

Thanks for the video 👍

[@corvetteforthew7437]

Im so happy I found this channel

[@FoundAndExplained]

happy you found us and explained it!

[@TimTDM]

Woah. The model is great. Is it hard to do minor details in blender such as propfans? Love your content found and explained!

[@FoundAndExplained]

It's not! Im flirting with the idea of doing interiors in the future. Quick poll, would you want fewer videos if you could see inside the planes?

[@TimTDM]

@@FoundAndExplained I think the interior would be more interesting with your grounded series since it would be interesting to see inside the planes of failed airlines. That’s my opinion.

[@foxgaming76yt24]

@@FoundAndExplained woah doing interiors? That would be so cool. Appreciate your hard work dude. And also proud to say I subbed before 50k!

[@Man_of_TheWay]

High bypass turbofans became the reality. The hushed engines now are incredibly quiet and unusual sounding

[@Autism_Artistry]

This might become a reality with the new CFM RISE PROGRAM

[@scottgamedev8542]

Great video dude keep up the good work 👍👍👍✔️✔️✔️

[@FoundAndExplained]

Thanks! Will do!

[@lokesh303101]

Yes! Go for it.

[@xiaofanghuang2228]

The starting scene reminded me of mustard

[@sarcasmo57]

With fuel prices how they are at the moment I'm thinking of getting a prop-fan engine for my Hyundai.

[@duartevilelas9688]

Another great and interesting video. As for ideas for future videos, here's one: I remember reading somewhere that originaly there where multiple versions of the SpaceShutle (diferent engine configurations, diferent launch system, etc.) that were considered/developed before we got the one that was used. What don't you "Find and Explain" what those were? I believe it would make for an(other) interesting video, not much different from that Boing 747X video. Best Regards.

[@FoundAndExplained]

Great idea! Going to do some more space ones soon

[@bradleyrex2968]

Prop fans were very interesting, but they never achieved the performance that was hoped for. In addition the noise would always be a problem. As bypass ratios increased, those figures were achieved and surpassed with the high bypass engines we have today.

[@robertdragoff6909]

A fast prop driven airplane was tried in the 50's It was made by Republic and was part of the Thunderjet line. IT was a fighter developed for the Navy. Only problem was, when it was on the ground the prop spun so fast the noise it made made the ground crews sick! Another design that went into the shredder....... But that was in the past. I wonder what's in store for the future? Maybe you can do a video about what's on the drawing board.

[@Tomi.762]

I think propfan development should be continued. I mean we can work on the noise level, so why not?

[@foxgaming76yt24]

The problem was, when noise level was reduced, engine efficiency would also decrease with it, making the design itself redundant. Would need either a major redesign or a new type of engine.

[@Tomi.762]

@@foxgaming76yt24 ah, that makes sense.

[@shmaknapublar]

They did continue the work, but moved towards ultra high bypass ducted turbofans, taking all of their unducted fan data with them.

[@OwenConcorde]

I never heard about this interesting cancelled 747 variant until now and that's awesome! Since you did a video on the triple deck aircraft concept, so what about the interesting concept of the "Boeing Super Clipper"? It looks like a three-headed 747 with canards and it only lands in the water because of its gigantic size. I only saw a few pics of it including a cut-away and a size comparison to the 747-400 and the A380.

[@FoundAndExplained]

Yes there is a LOT to do! I actually discovered this 747-500 during the script writing of the 747X video and it was so nuts it had to have its own video. the video was SUPPOSED to come out the next day, but i got caught up making all the 3d!

[@foxgaming76yt24]

Also this is off topic, but talking about wwii would also be very fun, and so would pretty much talking about ships or cars or anything. Would give you lots of topics to talk about, and won’t make your videos stale. So yeah, I would definitely recommend broadening what you post.

[@FoundAndExplained]

I think everyone wants me to take more steps into military things! Even if not planes :)

[@foxgaming76yt24]

@@FoundAndExplained yeha that would be cool! But if you ask me, doesn’t have to necessarily be military either, any vehicle would be fine.

[@marjan8888]

It already excites,it’s a747-400 that has a high bypass fan.

[@leiladaquil6587]

that is more than possible,but for me,the deadweight reduction is the most thing to be think on,then go to engine style I like.

[@jamescarlson4550]

Recommend Read Wikipedia article on propellers and correct propeller pitch in animations. Pitch parallel to airflow (feathered) happens when engines are shut down in flight. Your animation shows feathered props rotating.

[@docvolt5214]

It's actually beautiful

[@safetyfirstintexas]

Put a nacel on the turbofan blades to contain the noise generated with the turbofan blades. The regular jet engines have them that big now. Or did you overestimate their efficiency?

[@leekyo1502]

Which engine's thrust(power) is better?The turbofan-powered jet or propeller-powered jet?

[@TomEarley]

Please do a video on passenger chinook helicopters and why they failed. British Airways used to use them to ferry passengers between Heathrow and Gatwick.

[@FoundAndExplained]

What a great idea

[@rolandtamaccio3285]

How do the latest fan engines stack up, efficiency wise, to the proposed prop jets ?

[@benturp3492]

Depends on altitude. Props cannot go as high or as fast. This video is aloda bollox

[@rolandtamaccio3285]

@@benturp3492 ,,, the fact that GE was flying a tri engined jet all around the world with a prop on one side, and a jet in the middle and on the other side, seems to me to make your statement somewhat stuff-shirted .

[@benturp3492]

@@rolandtamaccio3285 what aircraft was this? Am an aircraft engineer buddy

[@rolandtamaccio3285]

@@benturp3492 ,,, I think it was a 727, GE had their own . My cous had the best job in the world as part of the crew . My guess is the bsfc was good, but not enough to continue . Must have flown out of the Cincinnati area .

[@myusername3689]

With current and future quieter prop blade designs and the rise of electric planes, propfans could make a comeback in the form of regional electric airliners to give them amazing efficiency and low emissions.

[@onair6652]

Great video, thanks for sharing

[@FoundAndExplained]

Thanks for the visit and thanks for subbing :)

[@TheDavidlloydjones]

I have an idea: they might have put propeller-blades on at an angle instead of parallel to the air-flow, as shown. That would have made them produce some propulsion by pushing the air backwards, see?

[@shmaknapublar]

They were variable pitch, just like a turbo prop. ;) You could have zero thrust at full rpm, reverse pitch for braking and backing up, or feather them into the wind stream for minimum drag during engine out procedures.

[@bencoss7003]

I would love to see a video if you already don't have one on the North American f-86 saber

[@Incognito-vc9wj]

Seeing those exposed blades near the wing fuel tanks, what could go wrong?

[@johnbockelie3899]

Have a few blades break off during flight, looks safe to me to fly a knife throwing plane.

[@ExaltedDuck]

It's kind of amusing that the shroud less turbofan made it as far into development as it did. Those things made awful noise. Ultimately, they were just a footnote on the way from the fuel guzzling, smoke belching, sometimes even after burning traditional turbojets to modern high bypass turbofans (which offer almost all the advantages of the shroud less fans but with maddening groan that sounds like the atmosphere itself is being unzipped. Not to mention a failure like with that 777 a few weeks ago would be far more dangerous without the nacelle to contain it)

[@bencemuller7919]

What about the turboprop engines with deltawing? Like the tu-114. With modern technologies, it could be interesting.

[@guitarplayerforu]

I think with the modern engine technology we have today, they could make a Propfan that has noise levels comparable to that of the latest Turbofans 👌. As far as the 747, I think Boeing did the right thing to wait for new technology before launching a successor to the 400, but even the 747-8i ultimately couldn't save the 747 as a passenger Aircraft unfortunately, even with 787 technology.

[@amargoun]

Considering the improvements un turboprops - both performance and noise- the question Is: why not an airliner similar to the Tupolev Tu-114 Roosya but without its drawbacks? Think of a DC-8 ir a B707 with the engines and propellers if the Airbus A400M.

[@Iceiznice34]

I love your videos♥️

[@FoundAndExplained]

Thanks so much!

[@TroysMilitaryHistory]

50K - nearly there! Hail Nick!

[@FoundAndExplained]

Nearly there!

[@TroysMilitaryHistory]

@@FoundAndExplained50.2K... There!

[@SupernovaeTech]

Live stream idea: fly historic routes in MSFS or XP11

[@southwestxnorthwest]

Boeing made and flew a propfan prototype in 1988 at an air show, but that was it.

[@armandomelko3266]

great video Nick! can you consider doing a vid about the 747 tri-jet?

[@FoundAndExplained]

Already on the channel!!

[@cfalletta7220]

Why didn’t you explain how the engines work?

[@airtexaco]

This was a good one, thank you. Wonder what could have been done to quiet the engine? Perhaps ducted like a high bypass turbofan???

[@davidhoffman1278]

There is a low noise spot of blade counts, blade angle, blade rpm that works for cruise, but outside of those conditions it's going to be a noise and vibration beast.

[@TomEarley]

This channel is way better than Mustard.

[@FoundAndExplained]

thanks for the comparison but Mustard is still the king!

[@tonysu8860]

And yet, With the current latest enormously larger turbofan engines, the so called propfan might already be back and commonly used in its new guise... Instead of exterior counter rotating blades, the compressor fans have been made out-sized huge and the extra air flow "bypassed" to the rear and expelled around the exhaust of the jet exhaust.

[@emaheiwa8174]

The 7J7 should have been built. But its boeing... 🤦🏻‍♂️

[@blastaviation2199]

You clearly didn't watch the whole video

[@emaheiwa8174]

@@blastaviation2199 they had airlines who wanted it and they F-ed the plane

[@foxgaming76yt24]

@@emaheiwa8174 you can’t blame Boeing too much. GE was the one who pulled the plug on the engine in the first place. Also, it was kinda destined to fail. It was notoriously loud, and lowering the noise of the engine would have made it less fuel efficient, so it would have been pointless, and lots of development costs are lost. And another reason they stopped it was because propfans weren’t needed anymore. Airlines kinda needed it back then because fuel prices were high, but once the price of fuel went down, pretty much interest in the engines went down together. This resulted in the shut down of the program. Maybe they should start it again, but I’m not sure if anyone is willing to make such a risk, since it requires a huge amount of money to either majorly redesign or produce and new kind of engine with similar specs from scratch.

[@nntflow7058]

@@foxgaming76yt24 For it's time, the engine's noise might be acceptable. If they kept it around, by now, they might have created a new version that is less noisy and more fuel efficient. The propeller would have revolutionized the aviation industry by now.

[@foxgaming76yt24]

@@nntflow7058 it wasn’t acceptable even back then. Many airlines had major concerns for the noise. And like I said, fuel prices went down, so it died. Based on the methods tried back then, lowering the noise would have reduced fuel efficiency. If you ask me, another type of engine that has improved efficiency will be good. But now, the engine are already much more efficient, so I doubt any project like that will be restarted.

[@fahmirblx]

Hmm... maybe start another series where subscribers send you their blueprints of their own design, you model them in somewhere & fly them in X-Plane 11?

[@mikeherbst1825]

Use a negative sound generator to cancel the noise.

[@ExTofia]

Awesome 😎 😎

[@michaelveis5950]

I would have loved to have seen it fly.

[@fredocarroll]

This is an interesting topic, but you've got some substantial inaccuracies in this video. First of all, the design of the propfan you show on the model is incorrect. Second, the size of the aircraft model is incorrect. Third, your explanation of the reimagining of the 747-500 is wrong, due to these previous errors. 1. Boeing's idea for the 747-500, as discussed in the _Financial Times_ article that you included as a screenshot, was for a shrouded propfan. The result would be an "ultra [high] bypass-ratio engine" with a figure of 15:1 or even 20:1. As the article notes, "Mr. Sutter said the fans would be shrouded by a large cowl." In other words, there was still going to be a nacelle surrounding the blades. Your depiction of it as being in the vein of the MD-94X is not at all what Boeing had in mind. 2a. The 747-500 was an enormous up-sizing of the 747 airframe. It was approximately a 30-frame stretch, making it one of the larger 747 variant conceived. It would have had a whole-new wing with a stretched wingbox and fuselage plugs fore and aft. It's that enormous new wing that allowed fuel volume for the greater range: Boeing was speaking of a 10,000 mile (8,700 nmi, 16,000 km) capability. Calling it an extended upper deck does not do justice to the concept. The model you show looks nothing this plane. You just took a -400 and put GE36 engines on it. I get that you wanted a visual demonstration, but if you're not going to depict anything even close to the design, why bother? 3. Your errors about the engine configuration lead you to your last major mistake. At 5:37, you say: "Boeing would then re-evaluate the design, to include one with other engines, the normal turbojets, but there were still some other issues." Not at all true, in the context of the picture you show. The "normal turbojets" you circled aren't normal turbojets at all; they aren't even normal _turbofans_ (since the 747 has never been turbojet powered). Those _are_ the UDF engines that Boeing had in mind for the 747-500. You can see the outsized nacelle serving as a shroud for the 10-12-foot radius fan blades. That picture is, quite simply, a sketch of the basic 747-500 concept, with the new wing, shrouded UDF engines, and enormous fuselage stretch (just count the windows). It's wonderful that you want to discuss these interesting aviation history avenues, but please be a little more accurate about it. I don't even work in the aviation industry, and I'm spotting these errors.

[@charlieiskandar1597]

Nice green 747

[@christopherflack7629]

Really interesting stuff.

[@alexandermathar7780]

If it had been built, it would probably still in service ! Perhaps they would swap the GEs for the new SAFRAN engines.

[@AaronSmith-kr5yf]

So what would happen when one of those blades failed?? Would it just slice up the fuselage or what??

[@emiliabusayong1102]

Perfect channels great job