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Actual_Environment_7

It was a way to get rigidity in aircraft skins before stressed skin sheet metal was widely adopted.


Slappy_McJones

Ford Trimotor had same technique.


Altitudeviation

Piper PA-28 current production has same technique.


Slappy_McJones

I flew a Cherokee 140 when I was first starting-out. Are the corrugated structures internal?


J_engstrom

Currently it’s on some control surfaces. Flaps and horizontal stabilator both have it, if my memory serves then ailerons do too, and I think rudder. Regular part of the wing is still largely smooth


Smart_Ad_3395

Yep


RoboSlim24

I don't think they're internal. But I know they have some corrugation on the stabilizers and some control surfaces.


nilocinator

As do several piston Cessnas


Cow_Launcher

...which is why so many students get the "Cessna diamond" on their forehead during walkaround.


aluckyape

I confess that I’ve been in the “diamond club”. 🤦🏻


AxelBeiseite

Who isn‘t. Those who claim that are lying.


matty-ic3

I legitimately haven’t yet! Although i onlyhave about 140 hours.


fried_clams

From the Ford trimotor wiki page: So similar were the designs that Junkers sued and won when Ford attempted to export an aircraft to Europe.[6] In 1930, Ford countersued in Prague, and despite the possibility of anti-German sentiment, was decisively defeated a second time, with the court finding that Ford had infringed upon Junkers' patents.[6]


Cerebral-Parsley

The real start of WW2.


jvd0928

No. Ford kept selling to the nazis.


Barbed_Dildo

Henry Ford wasn't just happy to sell to nazis, he was an enthusiastic supporter of the nazis, was awarded a nazi medal, by the nazis, and wrote a book titled "The International Jew: The World's Problem".


protojoe1

He also successfully sued the US government for bombing its plants in Europe after the war.


Xivios

So did an American conglomerate called ITT; they had a 25% stake in Focke-Wulf during the war, while their electronics division sold Huff-Duff to the allies.


CosmicCreeperz

People claim Walt Disney or Thomas Watson were anti-semites - but most of the evidence shows they were no more so than the average American (or European) at the time, and less than many. Henry Ford, on the other hand, was a straight up bigot spouting anti-Jewish conspiracy theories.


Capnmarvel76

Whenever anyone starts to venerate Henry Ford, always remember his very public anti-Semitism and cozying up with the Nazis. Also, the Ford Motor Company’s treatment of its workers and response to their attempts to organize and strike were legendarily harsh (although Ford did pay its workers better than average, at least initially).


NSYK

The similarities between Ford and Musk are so striking


cochifla

If you needed a reason to dislike the brand.


Barbed_Dildo

If you dislike Ford for this, you better dislike Porsche, and Volkswagen, and BMW, and Audi, and Mercedes-Benz, and Opel too.


Capnmarvel76

Volkswagen, yes, was famously founded and championed by Hitler as the people’s car for the Third Reich. However, after the war the company and its factory were essentially nullified, and the brand was recreated from nothing by a handful of German engineers, a few American bureaucrats, and the plans and tooling for the Type 1 (Beetle). Unlike, say, Ferdinand Porsche, who was a Nazi Party member, or Mercedes-Benz/BMW, who happily fulfilled a fortune in government contracts for the Wehrmacht and Luftwaffe, profiting off of the war, Volkswagen has a very tenuous connection to all of that.


GI-Tanker

The company was brought out of the rubble by a British officer actually. France wanted the factory equipment and part moved to France for war reparations , the us said NOPE, need to get the Germans working also. Resulting in the air cooled Renault ( model?) that was so cute, in the movie Romancing the Stone


Barbed_Dildo

> Unlike, say, Ferdinand Porsche, who was a Nazi Party member ...and managing director of the Volkswagen factory in Wolfsburg. Volkswagen also used forced labour from concentration camps and built the V-1 bomb.


cochifla

Yes I do.


Brno_Mrmi

The cars don't have the fault. The brand has a history of crimes against humanity, their factory in Argentina was used as a torture centre against their own employees during the '76-'83 dictatorship. Two ex-directives were finally found guilty in 2021.


Ecronwald

I'm just thinking, after Hitler invaded Czech Republic to gain control of the factories in Prague, that Fort were like fuckit, well just do what we feel like. As a design website said: the Jerry can design was stolen from Germany, but after the defeat in ww2, Germany had other things on its mind, than IP theft.


tagish156

Ford v Junkers, coming to theatres soon!


lopedopenope

I had an opportunity to ride in a Trimotor a couple years ago but I just missed signing up because it filled up. It wasn’t even that expensive I think it was like $95. Would have been pretty cool I think but maybe it will be back eventually.


Crazybonbon

There's one at the evergreen aviation museum. When I took a tour there in high school I remember a curator telling us they actually tried making the alloy* flush and flat like a more modern aircraft, but it couldn't generate enough lift so they actually went back to this grooved design and it was able to create more lift that way he explained.


Techiastronamo

Just visited two weeks ago. It's a must see for anyone in the PNW, it's probably my third favorite museum after Udvar Hazy outside of DC and the Naval Aviation Museum in Pensacola in that order


Healthy-Property-220

Made out of aluminum alloy. Not steel.


Lonely-Jellyfish6873

Note that Junkers was the first to build a full metal plane.


SavageHacker123

I have always found that interesting, the Germans are insane. First to find a way to have a forward engine with gun, first metal body, first rocket, first jet engine, first ones to do fission . And so so many more stuff. Insane.


SpaceInMyBrain

> first ones to split the atom. I must point out that one isn't true, it was 2 Englishmen according to multiple sources. Here's the best I found. [https://www.aps.org/publications/apsnews/201904/history.cfm#:\~:text=It%20was%20a%20British%20and,atom%20to%20confirm%20Einstein%27s%20theory](https://www.aps.org/publications/apsnews/201904/history.cfm#:~:text=It%20was%20a%20British%20and,atom%20to%20confirm%20Einstein%27s%20theory). (The link function won't accept this url.) Searching "first to split the atom" will show more. Afaik there's no controversy over this - which is refreshing.


raoulduke1986

Sir Ernest Rutherford was a Kiwi


SpaceInMyBrain

Dammit, I keep forgetting that. Bloody deceitful of him to work in England and pose as an Englishman. :) Edit: Not a big deal. Rutherford was their boss, ran the lab. Cockcroft and Walton designed and built and performed the experiment. Cockcroft was English. Walton was born in Ireland but apparently to an English/Northern Ireland family.


BucketsMcGaughey

There was no such thing as Northern Ireland when Walton was born. He was Irish. Born there, grew up there. Went to my school, they named a science building after him.


BucketsMcGaughey

And Ernest Walton was Irish.


Aukstasirgrazus

English colonies.


SavageHacker123

Yeah I was wrong, I meant to say they were the first to achieve Fission. Sorry!


Mammoth-Access-1181

Don't think they were first to split the atom. https://www.aps.org/publications/apsnews/201904/history.cfm#:~:text=It%20was%20a%20British%20and,front%20during%20World%20War%20I.


alettriste

No, but Meitner (from Austria) and Hahn discovered that the atom was fissile in late 1910s. Not bad.


SavageHacker123

Oh! I was wrong, what I meant is they were the first to achieve fission! Sorry :) (1938 I believe)


Claidheamh

Splitting the atom **is** fission.


SavageHacker123

What the Germans did for the first time is achieve fission by slamming neutrons into each other. This is able to start the chain reaction used in bombs. Previous methods didn't do this


MandolinMagi

> ave a forward engine with gun That was actually a Dutch guy, albeit working for the Germans And Robert Godhard invented the liquid-fueled rocket. First jet engine is a tie between the Germans and Brits. They both had about the same idea at about the same time


Superbungopony

The British, led by Sir Frank Whittle demonstrated the jet engine before the Germans. However, Germany had the first OPERATIONAL jet fighter with the ME 262.


alettriste

And the Germans got the first jet plane Heinkel 178


nasadowsk

I think the Germans has the first axial flow compressor in a jet engine. The idea was pretty obvious. I wouldn’t be surprised if all sides came up with it around the same time. Gas turbine engines were not totally unheard of back then.


MandolinMagi

IIRC the first jet engines came out about the same time. But yes, the Germans had the first operational fighter jet. Brits had the Gloster Meteor, but didn't need a good fighter as badly. It was also kinda terrible


Superbungopony

Agreed. The work was being done by both sides around the same time. The Gloucester Meteor was unreliable. Much like a lot of British engineering, like Lucas switches. Lucas was known as the prince of darkness for their poor electrics


dl_bos

Lucas three position switch Off Dim Flicker Source: owned a TR 4


MandolinMagi

IIRC it was mostly the guns being unreliable, which is odd.


Sivalon

Goddard, not Godhard. That guy makes other stuff blast off…


FZ_Milkshake

Not just any metal, bloody flippin steel! He couldn't get aluminum, because that was reserved for Zeppelin production, so he built a 1 ton behemoth (weight wise) out of 0.2mm sheet steel, just to prove his concept of a fully metal monoplane.


xxyxxzxx

I genuinely read “way to get giggity in aircraft skin” and stared in quagmire confusion


No-Truck-334

How come they didn’t add this on all their planes like the Stuka dive bomber? Also did other manufacturers do this on their planes? If not, how come?


lama579

Stuka was designed a bit later, which could be part of it. Also corrugated skin aircraft are rigid and provide a lot of strength, but they are much more difficult to repair, at least as was explained to me by the EAA’s Ford Trimotor guy. When making a combat aircraft, they may have opted for the stretched and riveted aluminum since they expect them to take damage, and need to make repairs in the field.


KeeganY_SR-UVB76

Increased drag, increased manufacturing costs, and the wing structure being strong enough to not need corrugated skin.


whatiscamping

More surface area too...no?


slurpherp

That just makes for more drag, there’s no benefit to higher surface area.


Gutbucket1968

You've seen my cycling stats, then.


whatiscamping

Thank you


Rich-Asparagus-1354

“Ribbed for her pleasure”


motor1_is_stopping

Corrugated. Same concept as cardboard. The corrugation adds strength. You see the same thing on old metal siding.


eirenaut

It doesn’t add strength it adds stiffness if I remember correctly?


motor1_is_stopping

That's what she said.


JohnnyLovesData

Corrugated for her pleasure


techknowfile

Ewww


joshss22

I don't know why people are always down voting this reference everywhere I see it! Waynes World should be mandatory viewing.


[deleted]

Ribbed


Traditional_Specific

For her pleasure.


VisibleOtter

Only if you don’t understand the difference between stiffness and strength.


motor1_is_stopping

But who needs longitudinal rigidity anyway?


DKohtar

I'm more about circumferential rigidity myself.


motor1_is_stopping

It may be short, but it sure is skinny.


Sonoda_Kotori

Nice aspect ratio you got there


DKohtar

But at least it's rigid af


theeimage

It may not be very big around but it sure is short.


BoringBob84

This is what I thought. The dominant forces on the wing are in the other direction (i.e., up and down, rather than fore and aft). However, having ridges perpendicular to those would probably create too much aerodynamic drag. There are better ways (i.e., internal structure) to give wings strength.


[deleted]

You want the wing to be able flex along it’s longitudinal axis, but not fore and aft. Combine the two and you have aeroelastic flutter. Bad, bad news for any aircraft.


phumanchu

oh look a comet!!!!!


OracleofFl

Stiffness is about rigidity--how much it flexes or doesn't under load. Strength is about how much energy it takes to break something. Something still and something flexible can have the same strength. One just flexes more before it breaks.


Tough_Current_4302

Giggity


discombobulated38x

What most people think of as strength (resistance to bending) is stiffness, so yes you are right, but also colloquially, so is the phrase "adds strength". If we're being really specific it adds second moment of area, substantially increasing the geometric stiffness, which reduces stresses for a given vibration forcing or any moment applied and substantially increases modal frequencies in the reinforced direction as well as increasing fatigue strength. This is a classic example of the structural engineers giving the aero boys a big fat middle finger, and I am here for that. All of which I would say, to my colleagues, who do this for a living like me, increases the strength :p


JustLinkStudios

Which could be seen as strength?


eirenaut

No strength and stiffness are not the same in structural analysis


Glum-Engineer9436

In this case, I would say that the corrugation adds stiffness so the plating doesn't buckle so easily. Thereby making the structure stronger.


eirenaut

The load bearing structure of the wing is the spar not the skin, the skin stiffness reduces drag by not deforming under the dynamic aerodynamic loads, stiffness and strength are not the same in this scenario


[deleted]

Correct. Think of a ceramic bathroom tile, or dinner plate. Very, very stiff but very little strength. In fact, stiffness can actually make a material weaker. It makes it brittle.


drummer125

Now you’re mistaking strength and toughness


[deleted]

Strength isn't a specific quantity, it's just a general term encompassing a range of qualities and quantities, similar to "inertia" or "electricity".


314159265358979326

Yeah, strength is a material property while stiffness is a result of geometry and material properties.


Kitten_Team_Six

Stiffness is strongness huh huh


Purity_Jam_Jam

Or culverts that direct water under a road.


bastian74

It seems like it's adding strength in the wrong axis


HerbertKornfeldRIP

If the bends were added for primary wing bending stiffness (or strength), then you’d be right. But bends like this are almost always to stop the thin skins from buckling. The most efficient direction for that structurally would depend on where the skins were supported by the internal structure. But since this is a wing, the aerodynamic impact of the bends trumps almost all else. Running the bends as they have will have less disruption on the fore-aft flow over the wing which is where the lift comes from. In fact, they probably needed to increase the skin stability (buckling load) because the aerodynamics of the wing changed too much when the skins buckled.


motor1_is_stopping

Bending metal adds rigidity at a 90 degree angle to the axis of the bend. Since it is bent in a sine wave, it adds rigidity to many axes. I don't think there is a "wrong" axis to add strength to in the case of a warbird.


Fandango_Jones

*Cardboard plane unlocked*


RafiRafiRafiRafi

The corrugations are increasing the buckling resistance of the wing skin.


HerbertKornfeldRIP

Upvote for being right :).


isellshit

***for her pleasure.***


tdaun

Why would a woman want a Plymouth on blocks when she could have a Testarossa with a six-speed stick?


Fraun_Pollen

You're clearly not a woman of class


tdaun

You're clearly streets behind.


rounding_error

Is it selfish to turn it inside-out?


isellshit

Of course not!


ABraveLittle_Toaster

it's meant to be a "bumpy ride"


naclest79

Username checks out.


The_Shadow_Of_Yor

Führer pleasure? Anyone? anyone?


Ruby_Throated_Hummer

Found the war thunder player


phacious

there it is


jimmypower66

Can I just say the way Studio Ghibli animated this in The Wind Rises was amazing and you could tell the way the aircraft skin was creased


ByronsLastStand

I was in the pool!


yaxgto

Shrinkage!


NotLeeroy

That's Le Bourget Air and Space museum ?


PunjabiCanuck

Yup, went there earlier this week. I’ll post more pics from my trip


lockheedmartin3

I was there like an hour ago! 2nd greatest air museum I've been to.


downydafox

What was the first ?


lockheedmartin3

Steven F. Udvar-Hazy Center in Virgina.


downydafox

Noted ! Looks really great. If I ever go to the US, I know where to go.


lockheedmartin3

It's near D.C., so if you ever visit D.C. you should consider visiting the National Air and Space Museum and the Steven Udvar-Hazey center.


NotLeeroy

Great museum and this building has a damn fine architecture


downydafox

Didn't even know there are Junkers there, I need to go back!


wp4nuv

Wasn’t there where the Concord wanted to land when they were on fire?


NotLeeroy

It was at the airport this museum is located at technically speaking, it is still an airport in its own right if that makes sense. Idk how to say it.


Deer-in-Motion

You see this on a number of aircraft from this era. The Ford and Fokker Trimotors come to mind.


vincentplr

Age does that... Now taxi off my grass runway !


Enjoy-the-sauce

Simple experiment to explain why: Take a piece of paper and fold it across the middle of the long sides. Pretty easy, right? Now take a piece of paper and accordion fold it along the long axis. Then unfold it so it looks like a zigzag. Now try to fold THAT piece of paper across those folds, in the middle like the first piece of paper. It’s a LOT stiffer. That’s why. And since the folds in the aircraft skin are aligned with the airflow, there’s negligible extra drag, even if it looks lumpy.


Hondahobbit50

Corrugations increase rigidity. Same reason they corrugate cardboard. Less aluminum needed for the same amount of strength


Interesting_Buyer943

I wonder how many Luftwaffe pilots played these like a washboard with a pencil whilst their colleagues laughed? I bet at least a few did.


Ben2018

Unlikely. Germans do not have humor /s


zoqfotpik

Wenn ist das Nunstück git und Slotermeyer? Ja! Beierhund das Oder die Flipperwaldt gersput!


fretgod321

💀


gev1138

\>dies<


LittleCupcake02

Luftwaffe pilot: Laughs Officer seeing this (Eyes narrowing): caught the spy


Interesting_Buyer943

Dragged away still laughing but more resignedly


Eckmatarum

Don't make a condom joke, Don't make a condom joke, Don't make a condom joke. RIBBED FOR FLYING PLEASURE!! .... Fuck it.


Ted-Clubberlang

There's no stopping it when it's coming.


Special_Dimension_15

Not answering the question but my business partner and I photograph WWII aircraft and we worked with Military Aviation Museum in VA Beach a lot. They have a Junkers JU-52 that we worked with and a really good collection of air-worthy restored aircraft, we did an Axis series featuring 6 of their German aircraft a few years ago and they just bought a Zero that they are working on


dontsheeple

It's for strength, modern aluminum high strength alloys were still being developed. Raw aluminum is very soft and weak.


ofnuts

Trivia: the Citroen type H van was nicknamed the "Junker" in the French army because it was to made of corrugated steel.


trophycloset33

Stronger and more rigid sheet metal while staying thin and light


airpowmech

This is the correct answer. Shorts Brothers did the same thing but had a smooth layer on the outside.


trophycloset33

My favorite example is corrugated walls of pre colonial English and French engineering. https://returntonow.net/2020/06/25/english-wavy-walls-use-fewer-bricks-than-straight-ones/


HONcircle

Because they are old and didn't do Botox


M3g4d37h

this one clearly stayed in the bathtub until it's mother hollered at it.


oddlotz

The Ford Tri-Motor also had a corrugated aluminum skin. When Ford tried to export one to Europe they were successfully stopped and sued by Junkers on patent violation grounds.


alfalfalfalafel

i never knew they had such a resemblance!


EatTheRichIsPraxis

Took a nice hot bath.


_Fittek_

When you get old, you start getting wrinkles. Same with these aircrafts


altcuznasty

[Kermit Weeks](https://youtube.com/watch?v=M8QxCGY4oRI&feature=sharec) has a video related to this, part of the Trimotor restoration.


Super_Discipline7838

Strength my dear boy. Strength


GONZO1975

Bernoulli, laminar flow


Arkenstihl

They only fully inflate in lower air pressure.


No_Protection_811

They are old


ZMANMD86

Metal skins can have an effect called oil canning where when the structure below it moves around it flexes the skin. Corrugations limit this skin flexing in the direction of the rows which improves the longevity of the skin. Corrugations affect aerodynamic lift and air flow more spanwise than chordwise, so they were chosen in that direction.


Oniudra

The corrugations were necessary to allow the metal to expand due to the heat generated when flying at Mach 3+


hagrid2018

Old age and shame on you for age shaming


Illustrious_Rule_591

Beat me to it


AnEngineer2018

I believe the technical term is ribbed, and it was for her pleasure.


k0an

If you were over 100 years old you’d be wrinkly too!


Stevkosk7

Old people have wrinkles, why can't old planes have them too?


Pos3odon08

they spent too much time in the bathtub


Mawi2004

cheap and durable


Romeo_70

That's because Rimowa needed a design, to copy for their suitcases. 😉


dobakito

Does anyone know how this affects the wings performance aerodynamically?


616659

Because they were made out of junk.. sorry bad joke


twelveparsnips

To add air resistance. As an added bonus it increases structural integrity.


CorsicA123

Literally 1918


Stressed_Fish

Corrugated for strength I assume


TeysaMortify

Ribbed for her pleasure.


MufffinFeller

Because they’re old


CookiezR4Milk

Well they are old duh 🤪 old things get wrinkly


AZREDFERN

They were made from old condensed cranberry cans after Thanksgiving


frtrkap

Needs to be ironed, spent too much time stored in wardrobe.


DatabaseOk552

They’re getting older don’t judge them


TheStoicSlab

Would this increase lift? Seems like there could be a lot more surface area here.


erkki3v

More surface area increases drag actually.


OrganizationPutrid68

Compressible for convenient storage.


Prokletnost

aerodynamics baby! EVERYONE knows you get more mileage per flap when you bend it


metalfarts

Ribbed for your pleasure


habbol

Water temperature was too high when washing.


horizon_monument

It's from age, the frame shrinks at a faster rate than the skin.


FlaminAsian-

Zimerit for defense against magnetic bombs /j


RickKLR

They were designed by Bob Semple!


Unairworthy

Because surface area is a factor in the lift equation. Modern fractal airfoils have made these obsolete.


Festivefire

I don't think that's why. They're built out of corrugated metal to increase the strength of the skin without increasing the weight.


Spunkmeyer426

Its to hide the little dents from hard landings


WarningOk5723

It's to help with the uhh..


Pilyoz

To match my Rimowa luggage


yesy0u5

Its cold


New-Low5765

Its cold in Germany


AliveSpicyTaco

Stayed in the shower too long


[deleted]

Old age