Plane Crashed After 3D-Printed Part Collapsed (bbc.com) 46
A light aircraft crashed in Gloucestershire after a 3D-printed plastic air-induction elbow softened from engine heat and collapsed, cutting power during final approach and causing the plane to undershoot the runway. Investigators say the part was made from "inappropriate material" and safety actions will be taken in the future regarding 3D printed parts. The BBC reports: Following an "uneventful local flight", the AAIB report said the pilot advanced the throttle on the final approach to the runway, and realized the engine had suffered a complete loss of power. "He managed to fly over a road and a line of bushes on the airfield boundary, but landed short and struck the instrument landing system before coming to rest at the side of the structure," the report read.
It was revealed the part had been installed during a modification to the fuel system and collapsed due to its 3D-printed plastic material softening when exposed to heat from the engine. The Light Aircraft Association (LAA) said it now intends to take safety actions in response to the accident, including a "LAA Alert" regarding the use of 3D-printed parts that will be sent to inspectors.
It was revealed the part had been installed during a modification to the fuel system and collapsed due to its 3D-printed plastic material softening when exposed to heat from the engine. The Light Aircraft Association (LAA) said it now intends to take safety actions in response to the accident, including a "LAA Alert" regarding the use of 3D-printed parts that will be sent to inspectors.
It seemed like a good idea (Score:2)
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Re:seemed like a good idea at the time (Score:1)
Qualified to work at Boeing.
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Did they use PLA instead of carbon fiber 12 or something? LOL
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Will to be fair if it had been 3d printed out of Peak or a number of other engineering filaments then no it wouldn't. Believe it or not there are consumer printers that can print this high temperature filaments. Obviously be didn't use over of them. In less critical applications people have been 3d printing and air box parts for cars for years. And no they don't melt either. Engines usually run well below 270 C. But this is not an airplane obviously.
Re: It seemed like a good idea (Score:2)
Re: No kidding (Score:3)
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Yeah in this video about filaments [youtu.be] he describes it as a viable alternative to steel but... $700/kg, 400C print temp, 140C heated print chamber and it's not even the worst, apparently that's TPI/Kapton
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100% yes. It's called 3D print it in something with a low melting temperature. (Maybe PLA.) Then, pour ceramic around it. And use it to cast an actual fucking metal part. LOL.
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100% yes. It's called 3D print it in something with a low melting temperature. (Maybe PLA.) Then, pour ceramic around it. And use it to cast an actual fucking metal part. LOL.
Came to say the same. And depending on the geometry of the part, you might not even need ceramic. Some people also do "lost PLA" sand-casting.
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PEKK, PEEK or ULTEM are what I'd do if I need high temperature stuff. PPS-CF comes close, as I bought my Bambu X1E for that stuff. Tullumer stuff looks promising as well.
For stuff that sits in a car and likely won't warp in the sun, I just go ABS or ASA.
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That you can print with "many" consumer printers, Polycarbonate would be a decent choice. Glass transition is around 147 (296), and you can print it at a consumer level.
Alternatively, print it out of PLA, dunk it in plaster, and burn out the PLA. Then cast with an actual metal like aluminum (search for "PLA lost casting" on YouTube).
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Two samples from the air induction elbow were subjected to testing, using a heat-flux differential scanning calorimeter, to determine their glass transition temperature. The measured glass transition temperature for the first sample was 52.8C, and 54.0C for the second sample.
With a Tg of around 54C this sounds like it was PLA. It was also missing the aluminium liner that's supposed to be fitted inside the normal epoxy+glass fibre version of the part.
Where did it come from. (Score:1)
If in the supply chain how common are 3d printed parts now for things like plane, autos, and even house hold repair?
Re:Where did it come from. (Score:5, Informative)
He bought it from a vendor at an airshow.
So either a counterfeit part, or some yahoos prototype that got sold off without proper testing.
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It's in the article:
The Cozy Mk IV light aircraft was destroyed after its plastic air induction elbow, bought at an air show in North America, collapsed.
Hecho en EE. UU., baby!
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This. There are some experimental aircraft that people have, where stuff like 3D printing parts is allowed, but the FAA rep is going to want a lot of documentation on the part and computed/theoretical loads on that part before he gives it a pass.
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Re:Where did it come from. (Score:5, Informative)
https://www.pilotmix.com/cozy-... [pilotmix.com]
For context for those not familiar with experimental/homebuilt aircraft. You can pretty much use anything off the shelf or custom. 3D printed parts (either self-sourced or purchased from dedicated vendors) are probably not uncommon at this point in time, depending on what you are using them for. Certified aircraft do not have this degree of latitude in terms of part sourcing and DIY work.
Now to the question about whether the owner made/installed the part, or it was sourced through the parts chain:
https://www.bbc.com/news/artic... [bbc.com]
"The Cozy Mk IV light aircraft was destroyed after its plastic air induction elbow, bought at an air show in North America, collapsed."
That sentence implies that the air induction elbow was purchased at an air show.
Reviewing the accident report ( https://www.gov.uk/aaib-report... [www.gov.uk] ), we get the following:
"The aircraft owner who installed the modified fuel system stated that the 3D-printed induction elbow was purchased in the USA at an airshow, and he understood from the vendor that it was printed from CF-ABS (carbon fibre â" acrylonitrile butadiene styrene) filament material, with a glass transition temperature3 of 105ÂC.
An alternative construction method for the air induction elbow, shown in the Cozy Mk IV plans, is a lamination of four layers of bi-directional glassfibre cloth with epoxy resin. The epoxy resin specified for the laminate has a glass transition temperature of 84ÂC, after the finished part has been post-cured. The aircraft owner stated that as the glass transition temperature listed for the CF-ABS material was higher than the epoxy resin, he was satisfied the component was fit for use in this application when it was installed.
A review of the design of the laminated induction elbow in the Cozy Mk IV plans showed that it featured a section of thin-walled aluminium tube at the inlet end of the elbow, where the air filter is attached. The aluminium tube provides a degree of temperature-insensitive structural support for the inlet end of the elbow. The 3D-printed induction elbow on G-BYLZ did not include a similar section of aluminium tube at the inlet end."
So apparently purchased through a 3rd party vendor, the owner installed according to an existing design variation (and got approval from regulatory oversight to do so), but apparently the 3d printed part installed did not meet the requirements for temperature resistance as compared to the glass-fiber/epoxy part specified in the plans, possibly due to the lack of that aluminum tube.
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Also, under testing, the plastic melted at *HALF* the glass transition temperature of what he thought he bought.
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Well, "half" is relative when it comes to temperature...
"Moron takes dumb shortcut causing plane crash." (Score:1)
I simplified the story for ya.
Re: "Moron takes dumb shortcut causing plane crash (Score:1)
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Ban 3D morons.
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Sad thing we are already having states pushing to do so. Look at the Flashforge debacle.
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No, try "sucker bought what he thought was a functional part that wasn't".
The material was apparently NOT CF-ABS, and wasn't properly constructed.
um (Score:1)
Not a home-printed part (Score:2)
From the linked article: "The Cozy Mk IV light aircraft was destroyed after its plastic air induction elbow, bought at an air show in North America, collapsed."
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Actually, I suppose the subject should be something like: "not printed by the pilot". Who knows how reputable the company/person was from which he bought the part... and what their supply chain looked like. But, given the information to hand, there's no reason to believe that the pilot had any knowledge of any possible problem with the part.
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Stupid ideas know no race,sex or economical class, they can and will happen to anyone and everyone, and hopefully they will survive it, and if they don't, well, the darwin awards could always use a new participant.
From thieves that think it's a good idea to try to steal the steel beams holding the ceiling to billionaires in a tin can that think they're above the laws of physics, the game is open to everyone.
what a moron (Score:2)
Did they print it out of pla for peek? (Score:2)
Inside job (Score:1)
Planes don't just collapse like that.
3D printing wasn't the problem (Score:2)
The problem was using a cheap substitute part. I'm guessing an injection molded ABS part would also have failed in that scenario.
CF-ABS is NOT like fiberglass at all. The CF is chopped into fine bits. They lend some stiffness at room temperature but not strength to the part. Certainly the carbon fiber bits don't lend any heat resistance.
Who's Stupid? (Score:2)
So the nanometer lathing of tungsten steel is no longer needed. We'll just print it at the milimeter level out of resin!
Better info (Score:2)
According to an AAIB Field Investigation report [service.gov.uk] (pg. 4), two samples from the intake were tested and found to have a glass transition temperature of 54.0C and 52.8C
So some idiot printed them in PLA. PLA is great but is very much NOT temperature resistant. It has been known to sag in a hot car.