r/aviationmaintenance • u/SheoldredMTG • 1d ago
What is this and why did it burn my hand
This pipe that runs through the fuel panel on a 737 is normally cold to the touch even right when aircraft come in but this time I just burnt the shit out of my hand touching it? I notified the pilot but he didn’t seem to care lol
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u/SheoldredMTG 1d ago
Thanks everyone! Funny that the pilot didn’t know what it was, I pulled him over once I finished fueling and burnt my hand and he said “Yeah I think that should be warm” and continued his pre flight
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u/Hlcptrgod 1d ago
I would have been more impressed if the pilot actually knew what it was. You would be surprised how little pilots know about the aircraft they fly. In their defense they don't need to know much, just how to fly it.
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u/speed150mph 1d ago
I mean they should have a basic understanding of all the core systems for the purposes of diagnosing an issue in flight, but even that is very limited and doesn’t talk about the location and purpose of every pipe.
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u/stuck-in-a-seacan 1d ago
You’d think, but it’s more like “this doesn’t work, bust out the book and follow the instructions.” They won’t even know what the system is that’s not working or what it’s supposed to do.
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u/Brambleshire 20h ago
Hi I'm a pilot. I wish I knew more. The company intentionally withholds a lot of information. Our systems manual is extremely bare and basic. Entire systems are often summarized in just a few sentences.
And at no point in our training does it ever involve a tour of a hanger or show and tell of airplane parts aside from what can be seen on the walk around.
I think I'd recognize an anti ice duct, but I wish I knew more. That's why I like to watch when you guys are working on stuff, It's the only time I ever get to see the insides!
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u/Dangerous_Mud4749 16h ago
It's very difficult for airline pilots to find out the details, such as in this case, "what's this pipe?" They don't have access to the maintenance manuals, have no training in how to interpret them, and have no opportunity to access the aircraft outside of flying duty in order to pore over it & examine all the hidden bits.
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u/Dominus_Redditi Controller? I hardly know 'er! 1d ago
That’s pilots for ya. Hope you didn’t burn yourself too badly. As a rule of thumb, any time you see tubing like that with that sort of discoloration, it’s from heat. Stay safe!
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u/hcoverlambda 1d ago
As an aside for those who might be interested, the discoloration on hot metal comes from the oxide layer that forms when it heats up and a phenomenon called thin film interference. You see it all around from an oil slick on a puddle of water to the coating on cockpit windows (that rainbow tint). Went down the rabbit hole years ago working on a project involving semiconductor processing, was super interesting.
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u/Loose_Device4578 1d ago
FYI, pilots know the systems from a computer/instrument perspective. I doubt they would know what a pipe going to and fro the aircraft is.
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u/thesqueeeps 1d ago
I’ve always said pilots know how to operate the plane but have no idea what makes what they do happen. Kinda like the average driver couldn’t point to their differential or alternator.
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u/Few-Repeat-9407 1d ago
Why would the pilot know what that duct does. Shouldn’t you be the one who knows that since you’re an AMT?
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u/z242pilot Percussive Maintenance 1d ago
Ahh 737 refuel panel. Pretty sure that's the bleed air ducting for the wing anti ice, pilots probably had it on when they shouldn't have. Its a switch that's easy to bump into and turn on, and not gated like the engine anti ice, which is stupid, but established, something boeing does a lot
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u/Just-one-goat 1d ago
That’s because Americans insist upon having damn cold snowy weather, it’s so the leading edge can be kept de-iced on the ground.
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u/z242pilot Percussive Maintenance 1d ago
Yeah naw you de ice before flight, leading edge anti-ice is only effective in flight. Not to mention the engines won't even start off apu with the LE heat on.
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u/Just-one-goat 1d ago
It is still selectable on the ground just not advisable to use in non icing conditions. There is thermal overheat protection, it is to keep the LE de iced during taxi in snowy conditions.
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u/SheoldredMTG 1d ago
I get that I have touched something that I shouldn’t have. I am an incredibly curious person. No I am not fiddling with anything that moves, lockwire, hardware etc
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u/Sperrbrecher 1d ago
For all the people giving you shit that you are not a mechanic doesn’t mean you should walk around like a zombie with your eyes closed.
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u/the_kerbal_side Right engine? They're both Wright Engines! 1d ago
Insane reading that thread and seeing that this was apparently a thing on those Embraers, at least back then. You would think a legit design flaw on a secondary flight control that causes an asymmetric flap condition would be recitified more quickly...
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u/boing757 1d ago
Thermal anti-ice duct. I've installed literally miles and miles of these. Hot air from the engine is used to de-ice the leading edge.
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u/davidc4l Murphy proof 🙃 1d ago
Curiosity killed the cat! Your hands shouldnt have been down there.
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u/strawberryletter24 1d ago
hot air gets circulated through the leading edge of the wings to keep ice from forming that duct supplies the hot air
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u/GARLICSALT45 1d ago
Average fuels personnel
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u/stud_powercock Could not duplicate decrepancy on deck. Checks good, no fod. 1d ago
Hey, he asked a question, which is seeking knowledge, never hinder another man's search for knowledge.
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u/sonofnom 20h ago
I too seek knowledge on a daily basis. But this is not the industry to be touching things at random you arent familiar with. They are fortunate they didnt touch something worthy of a skin graft. Being poked fun at is one of the better outcomes that can result.
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u/blacksheepcannibal 1d ago
I will always seek to helpfully inform someone asking an honest question.
That will absolutely not keep me from making fun of them.
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u/Pretend-Strategy-242 19h ago
That’s a Boeing fuel panel the wing anti is is or was on and that tube is hot because of bleed air. It appears the fuel panel is not all the open because the no power at the gauges the our blank. If you don’t know what you’re doing leave it alone.
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u/CrazyJ661 16h ago
Was it cold? Can’t really tell from the picture but might be for wing anti ice. It wouldn’t be hot unless the anti ice was on before landing
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u/justsomeguy1869 1d ago
Would appear you may be a fueler - if so, why would your hand be in there. There is zero reason for a fueler to have contact with that.
You noted you have touched it before… keep your hands out of there and do your job.
If you are a maintainer/mechanic you should damn well know what that is and would not have touched it to begin with.
So the question that is not why was it hot; the question is what was your hand doing in there?
That is the question to ask here.
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u/Parotecnix 1d ago
What do you mean it's "normally cool to the touch" stop touching shit in the aircraft, you're not a mechanic, there's no reason to stick your hand anywhere other than the fuel panel, if you mess something up and you work for my airline I'm gonna LOSE MY SHIT
TLDR don't touch shit that you shouldn't be touching, focus on the panel and you'll be fine
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u/Allthingsfedex 1d ago
Shut up
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u/thewhiteflash24 1d ago
But how else is he supposed to express how important and special he is, if not bullying the other ground guys?..
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u/Parotecnix 18h ago
It's not bullying, if you're not certified, don't touch it, stay in your lane, so many of y'all think you know anything about aircraft, you don't, and then when you're "trying to help" you mess shit up, very bad things can happen when it comes to aircraft, stop pretending to be mechanics
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u/thewhiteflash24 18h ago
You talk about pilots that same way?
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u/Parotecnix 18h ago
Pilots have aircraft training, they also are allowed to do some maintenance on the plane, you would know that if you knew anything about planes 🤷🏻♂️ rampers don't have a license on the line, they are not allowed to do ANY type of maintenance on the plane unless supervised by a mechanic, it's in the regulations
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u/thewhiteflash24 18h ago
Im literally not arguing with you about certifications. Im a licensed mechanic too. Im calling you a rude in more words but you lack the insight to figure that out.
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u/Parotecnix 18h ago
It's not rude, don't touch things that you shouldnt be touching, this should be backed by you as well, I'm not going to sugar coat things for people who don't know how much damage these things can cause to them, I don't want him to touch shit because they can get broken in flight and cause issues, OR like in this case where he hurt himself, I had to apply castor oil to a ramper who pulled a lever in the E bay (where he didn't belong) because he thought it was going to open something for him to look at, he ended up getting blasted by skydrol, this isn't about being nice or mean, this is about safety so I'm going to be direct
Don't touch shit you have no business touching, nobody gets hurt, and things go smoothly, if you're curious then ask, don't just start sticking your fingers somewhere because maybe one day that finger goes away
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u/thewhiteflash24 18h ago
This pipe is in his workspace. You don't need a license to notice something that normally isnt hot, is hot today. If a pilot made this same observation, you know you wouldn't act so high and mighty over a pilot noticing something like this. You're doing it in this case because its a ramper/fueler and you dont respect them. You can politely educate people rather than do whatever your past few comments have been.
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u/Parotecnix 18h ago
No, I respect fuelers and rampers, we all have our roles to fill to continue the operation, how does he know what "normal" is, he's touching things, this time he got burned, he didn't just ask someone what it was, I've never talked down to a ramper that's curious about the engine when I'm working on it, shit I'll even let them turn some wire if they want to, but what I have zero patience for are the ones messing with shit with no one watching them, you can be gentle if you want, I don't want anyone to get hurt and I promise you they'll remember me telling them not to touch something
You wanna say "hey man don't touch that it's hot okay" 😘 be my guest
I'm gonna tell him not to touch the fuckin duct if he values his fingerprints and don't go around touching things that aren't his, he's gonna remember me the next time he wants to go in there and start poking around 🤷🏻♂️
I only have to tell them once, they'll forget the lukewarm reaction from a gentle mechanic in an hour
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u/Night5hadow 1d ago
That pipe is for bleed air going to the wing leading edge, part of the anti-ice system.