Boeing Facts - Black lines on the wings

Sponsor: brilliant.org/mentourpilot/
On the wings of the Boeing 737NG's there are some curious black lines painted. They form boxes with some irregular shapes towards the back of the wings.
What are the purpose of those lines and can you really de-ice a Boeing 737 wing using Flower-spray cans?
These are some of the questions I will be coveing and explaining in todays video.
There are more videos coming up soon in my series about the Boeing 737 and its fantastic design so stay tuned!
To download my FREE app, use the links below! 👇🏻
📲IOS: appstore.com/mentouraviation
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A huge thank you to the following channels that I have borrowed some clips from:
8K Next: / @stunningvideos
Boeing:
/ boeing

[@k2midnight928]

I am a Boeing quality inspector currently working on the 737 lines in Renton,WA. I’ve been with both McDonell Douglas and Boeing for over 28 years working on and inspecting Aircraft. That being said your videos I find are around 99% accurate and well narrated with good explanations. Keep up the great work as your helping the flying public understand why it is we do things and how it affects them!

[@mikeyhau]

I wish university lecturers were even half as good as you in explaining things. You explain complicated things really well. Thanks for your work.

[@emergency1971]

I once flew from Sturup to Las Palmas with a MD83. Due to headwind we needed to land in Faro, Portugal, to fill up the tanks. Before takeoff the captain took a bottle of vodka from the taxfree trolley and put it on the Wings as de-iceing 😂. I saw it with my own eyes and he actually explained for us what he’d been doing. This was 1994.

[@sadmanh0]

I was imagining each pilot poking out of the window with those flower sprayers hosing the wings lol

[@AndrewFremantle]

Here's a fun question from a member of the general public: How often do (commercial) pilots screw-up in the simulator? Have you ever seen anyone crash-and-burn? What would the professional and career consequences be of such an event? Is there a difference between someone who is expected to be fully competent (re-assessment simulations) or someone who is still learning?

[@mthef10]

Do you know now?

[@hecdavid11]

"Here's a fun question" Proceeds to ask 4 questions. 4 very good questions at that 🤣

[@sharoncassell9358]

Of course. That's the place to mess up. Not in the air. Its practice and testing chamber. I deliberately crashed a c141 over the NY Empirestate bldg. To demonstrate terrain. Pull up. Before our planes had that in 1984.

[@bigtaxrefund]

im a pilot, avionic tech and aircraft mechanic..your videos are a great explanation to the general public..excellent job my brother!! two thumbs up!

[@JoeSchmoeLivesHere]

Boundary markers for frost?! I had no idea! Little wonder I enjoy your videos so much. Well done as always!!

[@CharlieGordonRailfan]

I love how you explain all of this information, and make understandable for people like me, who are not pilots, but love these aircraft. Thank you.

[@jpkalishek4586]

Ah, yes. Many a time I was fueling a -700 for SWA and had the frost melting to drip down my neck and back. Once, fueling a flight from San Diego, I opened the panel and felt the cold drop into my neck and then a bit later had a massive pain in my neck. it wasn't a drip, but a bee. Seems it had been inside the panel opening when closed in SAN, fell into my shirt when I opened the panel and as it warmed up it woke up and was unhappy with its relocation. Luckily I am not allergic to bee stings.

[@TheKaidynB]

Eek! I used to be afraid but I’m not anymore. I am allergic to bee and wasp stings so I would not have been so lucky.

[@jpkalishek4586]

@@TheKaidynB stay safe, and keep the Benadryl (or more) handy.

[@TheKaidynB]

@@jpkalishek4586 I have an epipen just in case

[@jpkalishek4586]

@@TheKaidynB Huzzah! May you never have need to use it! It's best to have, and not need, than to need, and not have.🙂

[@TheKaidynB]

@@jpkalishek4586 fun fact: I actually have it because I’m allergic to nuts

[@billbeyatte]

With every video, I gain more respect for pilots and their (your) knowledge of the many many aspects of safe flying.

[@lmcc8798]

Superb timing! I flew exit row on a new 737 two days ago. I first noticed the anti-skid on the wing egress path, then wondered what those black lines were for. No apparent reason! Thanks, very cool!

[@nickbreen287]

Thanks, I always wanted to open a factory that made replacement black lines for Boeing's and now I know what they are for!

[@daffidavit]

Mentor, you may want to do a video about the future of aviation and how students should select a good flight school if you haven't already. I wanted to be an airline pilot all my life, ever since I soloed at age 16 and got my license at 17 back in 1969. But back in those days, there were no airline jobs available to guys like me. The Viet Nam war would be ending in a few years and the military pilots would be getting whatever jobs were available. The airlines were not yet deregulated. So I went on into another line of work but kept flying general aviation all my life. Now, the airlines can't find enough people to fill the pilot slots. There is a dearth of pilots and will be for a long time. I've heard the airlines are desperate for pilots now. This must be a pretty new phenomenon. It's the first time in my life I heard the airlines are worried they won't have enough pilots. You young people who have aviation in your blood now is the time to learn to fly. But do your due diligence before you pay a flight school any money up front. Don't do that, hold on to your funds and pay as you go, unless you go to a large school like Embry- Riddle or FIT (Florida Tech). Smaller flight schools can go out of business and take your money with them. Also, you may wish to change flight schools or go to a warmer climate to learn. I've also heard the military is offering their own pilots incentives to stay and fly military aircraft because they can not afford their pilots leaving for the airlines for better pay.

[@TheJstewart2010]

Thanks so much for taking the time to do this. I never would have guessed that this was the reason for the black lines. I love learning from these videos. Every time I finish one, I can't help saying to myself, "Wow, that's really cool and interesting."

[@ShawnD1027]

I flew B-52s, and after long high-altitude flights where the fuel was completely cold-soaked, if you descended and landed into humid air, the wing would frost up even while flying -- you'd see large white patches against the dark camouflage.

[@MentourPilot]

Yes, that’s exactly what happens.

[@vformarallo]

Don Gregg it is a problem though, that's why they de ice the wings and spray anti ice in them.

[@vformarallo]

Don Gregg it interrupts the flow of the air and can lead to stalls. In smaller aircraft you NEVER takeoff with the slightest of ice, not even frost.

[@alan2804]

@@vformarallo i think Don Greg meant icing while in the air, not on the ground where de ice is available.

[@Bill_Woo]

One of the most fascinating technical explanations yet on the channel - and that is saying a LOT. This is the most consistently interesting channel of any discipline. It's always, always interesting, relevant, understandable, sometimes strongly surprising, and always, always, on a topic that I either have wondered about for years, and if not, something that I became fascinated with during the podcast. So after seeing so many wondrous, outstanding videos on Mentour, to say this is one of the most fascinating, as he explains the sloshing and frost issue - that's saying a LOT.

[@rudolfabelin383]

Thank you Petter! I now understand the helicopter scene, after many years, in "The Day After Tomorrow". I really thank you!!!

[@giacomo3223]

This explanation is very awesome.... WoW... I really liked it and the whole video. Great job as always Mentour!!!

[@lesb_socal]

Off-topic, but something I like is when taxiing, if already cleared for takeoff before final turn into the runway the pilot will kick the engines up while still in that last turn. That is SO COOL.

[@interstellaraxeman4468]

You explain things very well...concise, easy to comprehend, and pleasantly clear. Great new channel for me..

[@StatFlight407]

This is just fantastic information to absorb! So many things you bring to the channel & App have such meaning and relevance to even the casual aviation enthusiast. Please, by all means, continue with your videos and keep up the fantastic work. It is greatly appreciated by so many!!!

[@MohammedAshraf-cc7zw]

That Uniform 😢😭, it gives me goosebumps imagining myself in it..

[@livewellwitheds6885]

hope u can do it!

[@ThomasGrillo]

Thanks for explaining this. I've seen it once on a flight, during which, we had to fly unusually high to get over severe thunderstorm fronts.

[@thefurbeastunderyourbed5012]

Wow, you even have your own cup, envy you :D.

[@syamprasada.p.9841]

Thank you very much. Nice description, no exaggeration, exactly up to the point to follow. Also the examples are quite relevant and easy to understand.

[@stanleyallan6997]

Thank you Mentour. Very informative and easy to understand video. Well done!

[@xsupakane]

I found this podcast as always absolutely fantastic!

[@kevinstonerock3158]

Since you mentioned something about an over wing door my first thought was it could be an indicator for the areas you could safely step on the wing but then I began thinking it might be an indicator for snow or ice if it wasn’t visible. After watching I understand it but no credit for the initial guess. In the end I still learned something which is always good.

[@SwastikDwibedy0608]

Thanks a lot.. I always wanted to become a pilot now I'll be going forward in that direction because of your videos. I've started watching them.. almost completely 50% of all of them! Keep doing the good work buddy..

[@erikjohansson1814]

Swastik Dwibedy Once you have finished watching all 100% of videos here, you are ready to fly your first 747. Good luck oh voyager 👌🏻

[@sergipf1514]

you mean 737..

[@erikjohansson1814]

Sergi Pol Fauchs No, 747 since I would think that is the most iconic Boeing of them all.

[@skytrainii8933]

Eryk, 787 for me. But I always did like the DC-8, Super 8 from Douglas Aircraft the best.

[@skytrainii8933]

Swastik, I thought I did too. But then I flew the Navy C-9b's for 9 years as an FE and learned that most pilots had (ech-em) nominal college degrees. Most of my pilots (most were reservists that flew the the Majors during the week in the right seat and for us on the weekends in the left seat) were not really that smart. Mentor Pilot seems to be an exception. That is why I became an Aeronautical Engineer. In truth, determining how to enter a holding fix or determining when to start the timer on a DME approach was not that interesting to me. Now I design them and give the pilots all that automatic stuff that really flies the airplane. I love my job. But at first I didn't get paid as well as pilots. That is not true anymore. Pilots don't get paid as well now and I do pretty well working for one of the major manufacturers (in fact I would argue the biggest).

[@erixmacleod6097]

One of your videos a day keeps me happy yay 🙌

[@racsito39]

The flower spray anecdote reminded me of that video that surfaced months ago of an airliner that attempted a de icing with a 5 gallon container that accidentally slipped from the operator and smashed against the body of the plane

[@sharoncassell9358]

Maybe that's why they don't do it anymore.

[@sharoncassell9358]

Somebody must have fallen off the wing. Its slippery. My co worker was walking on the wing to check for ice, found some and slid off the wing 17 feet below onto his arm & backside. Luckily just bruised and embarrased.

[@alvarocifuentes6745]

I already knew this one, but it is always great to hear you explaining stuff! ;)

[@alvarocifuentes6745]

Porto M In his wings and in some center tanks

[@funastacia]

I've been binge-watching your videos all week long :)))

[@funastacia]

P.S. I really love this backdrop / video setup!

[@MentourPilot]

I hope you liked them!

[@rolandalfonso6954]

I swear, that if he keeps this up, the GDP of a lot of countries will take a hit due to a serious lack of productivity...He's the best.

[@funastacia]

:))) I loved them and I even mentioned your channel in my video this morning! Thanks so much for the hard and amazing work!

[@funastacia]

Ha-ha, well put, Roland! )))

[@hexprince]

Loved this! Really wonderful explanation. Thank you! :)

[@FM-qm2bn]

Thank you for all that you do ! Absolutely perfect! Have you done a video on the 737 rudder reversal issue back in the 90’s I believe ?

[@Equiluxe1]

And I always thought that it was to stop the wings tearing off, as nothing ever tears along the printed line.

[@YdnarLah37]

I had thought they were corogard markings. Thanks for the knowledge update.

[@danpedd6554]

I love learning all these facts! Thank you. Fun stuff.

[@MovieMan-gh2qn]

Thanks to people like you, I learn something every day !!!

[@garyodle5663]

Good explanation. The fact that they look so cool is just a bonus.

[@johnniewelbornjr.8940]

Very intriguing and well explained. The 737's have always been my favorite birds but I never really investigated the design differences in the NG's. Always a pleasure to get a few minutes to watch your different subjects, though, even though I'm not likely to ever fly anything GA with the least bit of deicing capability. I'll certainly think about it the next time I deliver one of Global Ground Support's deicing trucks, though (I've hauled several out of Olathe, KS to various US airports). Thanks for sharing these vids. :)

[@nomobilly]

Love the info, I always wondered about these things , great job thanks.

[@williamharvey697]

Always interesting! Thank you for taking the time to do this!

[@MentourPilot]

As long as you guys enjoy it, I will keep making them. Thank YOU for watching.

[@davidrevesz6088]

Awesome explanation Captain. Thank you👏

[@jessedechambeau7050]

Loving these 737 vids!

[@gweinrich]

I am a first time subscriber!!!I love what you said!!

[@applicareinc]

Excellent clear explanation. Thanks for posting.

[@FlyingInlines]

I was extremely excited for today's video :D 💙

[@tryithere]

Then it tanked.

[@MRLike-he4qg]

As always, great job. Mentour, can you make a video about mass&balance calculations? Also, calculations concerning the way for landing and takeoff?

[@mikecawood]

Thank you, I have wondered about those lines.

[@Corsairforu]

Thank you Mentour Pilot.

[@sharvari7253]

Hello mentour, can you please give information about ice detectors and other probes, their functions and the vital roes they play! I really love watching your videos as they are a great source of knowledge! Thank you for everything!❤

[@makantahi3731]

on an 32 there is some sensor that senses when between two contacts accumulate ice - i am not sure if it works on closed curent loop or change in capaciti or inductivity but there are some contacts that collects ice

[@sharoncassell9358]

Some planes have rubber boots installed in the leading edge of wings that break ice off when it forms. It is not automatic usually. Pilots select it. There's heat to melt ice also. There is de icing sprày like antifreeze to coat the wings in cold situations even in warm places because when you fly from 30 thousand feet it's minus 60 degrees up there.

[@rvnmedic1968]

Aviation fans can always learn something new via your videos. Very interesting re the fuel temp at altitude and then the effects upon landing. I guess the Boeing engineers might have thought to put a few channels around the tanks and have some engine exhaust gas run through it to keep the fuel warm. Thanks, Captain!

[@torben.u.f4722]

Thanks for this Video Petter

[@davidck1]

I've been binge-watching your videos all month long

[@ardalanm1652]

On the mentour aviation app my name is future air canada pilot I’m 15 and the app has really helped me So thankyou

[@svenderfoldy7659]

Thanks, I always though they were check strips across rivits to visually see rivit cracks

[@infotvglobal7334]

excellent mentor. no one can explain better then u 👍🏻

[@marinaisabelcotrinarengifo3318]

Love your vids. Keep up the good Work. Regards from Perú

[@tomcat514]

Mentour Pilot = Aviation knowledge = Gold treasure!

[@MentourPilot]

Thank you! That’s great to hear.

[@DavidJrReeves]

There are some old methods of de-icing still out there. At Buffalo Airways (the subject of the show Ice Pilots) the common practice is to stand out on the wing with a mop and a bucket of deicing fluid. Definitely more labor intensive but still way cheaper.

[@brucel.6078]

Another great informative video! Thanks for your time!

[@MentourPilot]

Thanks for watching!

[@PedroPepeDk]

Sucintly explained ! You do a great job , enjoy watching your videos ! ;-)

[@danielbengtsson1665]

As always, interesting video!

[@RichieRouge206]

Had no idea that’s what they were for, you are awesome to watch!

[@MentourPilot]

Thank you! I’m so happy you think so!

[@almorkans3945]

Learned something new today! Like a few others, I thought they defined the same areas to walk for maintenance staff.

[@sharoncassell9358]

I was an aircraft mechanic on C 141 .they outlined no step areas on wings but no black lines. That was 1984. Maybe now they have black lines too.

[@epicETgaming]

nice video........ keep it up. it was very helpfull!!

[@MrKEITHBT]

Great explanation again, keep up the good work.

[@leahknight1230]

i watched all your plane vidoes loved every signle one

[@fanekoman8288]

wow thank you so much for the Explanation!

[@MentourPilot]

Thank YOU for watching!

[@antoineandre2151]

brilliant! as usual! thank you !

[@abreeqchaudhry8419]

ive been watching you for 3 years

[@pepe2000ful]

I am soooooo sorry BOSS, just realized you are a CAPTAIN, respect and salute !!!! Four bars, my man !!!

[@RexyH267]

Another very informative video, great channel from one who grew up in the bays of piston engines.

[@MentourPilot]

Thank you! Great to hear that you like it!

[@JimmyD_C172]

Thank you, Captain! Great explanation.

[@MentourPilot]

Thank YOU for watching and interacting!

[@zoborey]

thank you for the valuable information captain

[@timol437]

Actually this was 1st a problem for Douglas on the DC-9. Originally intended as a short-haul A/C not ment to fly long periods at altitude limiting cold-soak time. As the DC-9 stretched and flew longer segments cold-soak frost/ice became an issue. Douglas painted two small triangles on each wing at the wing root. A small piece of yarn, about 12" long is attached within the triangle. If it freezes to the wing you have an Ice issue. Strange but simple.

[@emaildenis]

Great video Captain!

[@gauravparakh6608]

As always excellent video! Please make a separate podcast on fire system and how do they work Thanks in advance!

[@diegoarpino2080]

Great video as always! Could you possibly do another explaining a pitot tube? Thanks!

[@brucekendall52]

Interesting,thank you.

[@maxyakov273]

Thanks for4 the great explanation!

[@YazanTheFighter]

Epic as always 😊

[@MentourPilot]

Thank you!

[@petemac7969]

good video and good information. Never was aware of that

[@jimmeade2976]

Very interesting explanation of something that most people don't notice, or if they do, they don't care about. Thank you!

[@boatlover1875]

Very interesting! I worked at a small station in a southern US state. We usually had an overnight plane for a morning originating flight. We had a rickety de-icer that you towed around the plane, the only real need we might have was for frost a few mornings each year. Thankfully, it was never needed during my time there.

[@Roland_Rohrle]

Thank you for the insightful video...

[@sureshbharadwaj2779]

Fantastic presentation and very informative

[@MentourPilot]

Thank you!

[@skytrainii8933]

Actually, all modern jets have "Wet Wings". That means the entire area inside the upper and lower skins is fuel tank. The black lines on the upper wing are place at the fwd and aft wing spars; the fwd and aft limit to the wet wing fuel tanks. Or in other words, the fuel has always been in contact with the wing skins, thick and thin. The thinner wings on the newer 373's means less fuel volume. The less fuel volume results in the cold soak happening faster. I flew the Navy C-9s and we had long range tanks. We could fly none stop (5 to 6+ hours) cross country. We often had cold soak fuel that resulted in ice forming on the lower wing skins which was collected from the lower altitude humidity in the air. When we refueled, the warmer fresh fuel melted the ice and it rained under the wings.

[@i_kyce]

This was really helpful! Can you make your next video about Satcoms (AFT) and (FWD) Thanks.

[@mooniejohnson]

Wonderful video, as always! It did, however, put the image in my mind of one poor guy walking on the wing with a little spray-bottle to de-ice! :P

[@jimr3633]

You nailed it! The NG wing was full redesign to increase Mach number, increase altitude to 41k feet cruise, and increased takeoff weight, esp for the -900 for Alaska. Re the cruise speed, pilots I talked to called the old 737 the "Boeing Speed Bump" because faster planes stacked up behind or had to climb over them to pass. :) Do a video on the engines! The re-engine was the part I worked on the most.

[@kofManKan]

Great channel, keep it up fella!

[@Kevin19700]

Excellent information!

[@em1osmurf]

now i know why anyone in their right mind would need to de-ice on a hot summer day. thanks for your vids--i learn something new on every one of them!

[@steveneff7223]

That's absolutely Outstanding, the fuel frost Theory, " it's just frost Fellas!,.U guys R Cleared 4 Takeoff!😅

[@generalrodcocker1018]

very cool video, this is youtube gold! every day, i can learn new things is a awesome day.

[@MentourPilot]

That is true! Every new thing you learn is potential gold.

[@RichardWraith]

Isn't it nice that he advertises something that is both relevant, and that he understands :-) Unlike all the other KZbinrs who advertise any old junk that gives them money... Takes a pilot to get it right huh :-)

[@ParkerW95]

When I have a question about the Boeing 737, I always come to your videos.

[@petesheppard1709]

It seems crazy that a thin, almost invisible layer of frost can kill the lift and keep a plane from taking off, but that is absolute truth. As a general aviation pilot, I've had to scrape frost off more than once. Some small airports use an alcohol solution applied with a hand sprayer to deice GA aircraft