9 ms·

This is the mechanical equivalent of vibe coding. 3D printing itself isn't exactly to blame but the negligence of the company that created and sold this part an

by fudged71 11mo ago

This is the mechanical equivalent of vibe coding. 3D printing itself isn't exactly to blame but the negligence of the company that created and sold this part and omitted it's use from an inspection. Just because a part has the shape of an engineered part does not make it compatible, strong, safe, and fit for purpose. This part could have likely been fine if it used a different material such as Ultem.

deleted 11mo ago
[deleted]
delichon 11mo ago
> blame ... the negligence of the company that created and sold this part That should be so obvious that I wonder if it was DIY by the pilot.
- deleted 11mo ago
  [deleted]
- ElijahLynn 11mo ago
  > The Cozy Mk IV light aircraft was destroyed after its plastic air induction elbow, bought at an air show in North America, collapsed.
- michaelt 11mo ago
  https://en.wikipedia.org/wiki/Cozy_MK_IV https://en.wikipedia.org/wiki/Cozy_MK_IV > The Cozy Mark IV is a 4-seat, single engine, homebuilt light aircraft [...] The aircraft is built from plans using basic raw materials. It is not a kit aircraft You could scarcely get more DIY than this aircraft. Home-built, and not even from a kit - the builder gets to lay up every part in glass fibre themselves, by hand. And this guy had been flying it for 26 years. It sounds like the guy was sold a part 3D printed in the wrong plastic, and it melted. He thought it was ABS, but it melted at the temperatures PLA melts at. If your engine air inlet is made of plastic that melts at 54°C (130°F) you're going to have a bad time. It's easy to imagine how a chaotic 3D printing business might have run off a test part in a cheaper black plastic, then a confused worker could have stored the test part in with the other 'identical' parts in a different black plastic. The 'serious' aerospace industry avoids this with lots of paperwork and procedure; when an airline maintains an airbus plane, they use only airbus-approved parts from airbus-approved sources with a paperwork trail confirming they were inspected for being-the-right-material using an approved procedure. I don't know if the home-built aircraft community would be eager to adopt those practices, though.
- dghlsakjg 11mo ago
  > That should be so obvious that I wonder if it was DIY by the pilot. I don't know how the regulatory environment is in the UK for experimental craft (this is considered to be "experimental" category in the US and Canada), but yes, the idea behind an experimental is that everything is DIY. I have an experimental, and I can do close to anything I want. What I can't do is complain when my plane crashes because I installed a part that isn't fit for duty. I, as the owner and operator, am the one that signs off on the airworthiness of the plane. E.G. If I install a Cessna part on my plane, and that is the cause of a crash, that is my fault from the point of view of the FAA. There may be legal considerations outside of airworthiness and flight rules, but as far as the FAA is concerned (or would be if this had happened in the US), the manufacturer of a part is off the hook once the thing is installed on an experimental.
elicash 11mo ago
In what way is this like vibe-coding -- or do you just mean both are bad? According to the report: > 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 – acrylonitrile butadiene styrene) filament material, with a glass transition temperature3 of 105°C. https://assets.publishing.service.gov.uk/media/69297a4e345e31ab14ecf6e9/Cozy_Mk_IV_G-BYLZ_01-26.pdf https://assets.publishing.service.gov.uk/media/69297a4e345e3... Isn't this simply a part that shouldn't have been allowed to be sold based on it being both faulty and also misleading?
- johnnyanmac 11mo ago
  The implication was that the part took shortcuts and made something that only looked good on the surface. But couldn't stand up to deeper scrutiny.
- hbrav 11mo ago
  Well how confident would you be that this part isn't exposed to temperatures above that glass transition temperature? It is installed near the engine.
  - film42 11mo ago
    Installed _on_ an engine that operates at 200ºC!
  - plorg 11mo ago
    The report further states that the part included in the original design (part of the kit) was made of a carbon fiber composite where the epoxy had a listed glass transition temperature of 84⁰C. If there is an element to be critical of along these lines it's that the part as originally designed is supposed to include an aluminum tube at one end that may stiffen the part - the report makes no conclusions whether it truly would have, but notes that the actual glass transition temperature was found to be much lower than listed, and lower than that of the epoxy used in the original design.
- 11mo ago
carabiner 11mo ago
Vibe coding can make code that is suitable for production. 3d printed plastic can not be a substitute for a fiberglass-metal part.
- shmeeed 11mo ago
  It absolutely can. Not all 3D printing is kids' toys. In the end it depends on the application. Vibe coded flight management systems, anyone?
sho_hn 11mo ago
I think a more useful definition of vibe coding is "something you can do when it really doesn't matter". Which requires a hell of a lot of judgement to know when it doesn't. Installing life-critical parts of shoddy engineering into a vital system of your airplane is a good example of when things do matter.
phkahler 11mo ago
>> This part could have likely been fine if it used a different material such as Ultem. Maybe, but FDM printed parts are still much weaker than molded parts. We tried printing some coolant pump housings once during development. They worked fine until the pressure went up and then layers separated and someone got to clean the lab. At least an air intake is gonna have negative pressure which might help hold the layers together.
- PunchyHamster 11mo ago
  but it didn't fail because of stress. It failed exactly because it was made from wrong material. If the exact same part was injection molded from the same material it would melt too
itopaloglu83 11mo ago
It’s also a validation failure as well, because somebody assumed that the 3d-printed part could work as intended without validating it under various use-cases and situations. Looks like they would like to make the early flight mistakes themselves instead of following air worthiness guidelines.

deleted 11mo ago

[deleted]

delichon 11mo ago

> blame ... the negligence of the company that created and sold this part That should be so obvious that I wonder if it was DIY by the pilot.

deleted 11mo ago
[deleted]
ElijahLynn 11mo ago
> The Cozy Mk IV light aircraft was destroyed after its plastic air induction elbow, bought at an air show in North America, collapsed.
michaelt 11mo ago
https://en.wikipedia.org/wiki/Cozy_MK_IV https://en.wikipedia.org/wiki/Cozy_MK_IV > The Cozy Mark IV is a 4-seat, single engine, homebuilt light aircraft [...] The aircraft is built from plans using basic raw materials. It is not a kit aircraft You could scarcely get more DIY than this aircraft. Home-built, and not even from a kit - the builder gets to lay up every part in glass fibre themselves, by hand. And this guy had been flying it for 26 years. It sounds like the guy was sold a part 3D printed in the wrong plastic, and it melted. He thought it was ABS, but it melted at the temperatures PLA melts at. If your engine air inlet is made of plastic that melts at 54°C (130°F) you're going to have a bad time. It's easy to imagine how a chaotic 3D printing business might have run off a test part in a cheaper black plastic, then a confused worker could have stored the test part in with the other 'identical' parts in a different black plastic. The 'serious' aerospace industry avoids this with lots of paperwork and procedure; when an airline maintains an airbus plane, they use only airbus-approved parts from airbus-approved sources with a paperwork trail confirming they were inspected for being-the-right-material using an approved procedure. I don't know if the home-built aircraft community would be eager to adopt those practices, though.
dghlsakjg 11mo ago
> That should be so obvious that I wonder if it was DIY by the pilot. I don't know how the regulatory environment is in the UK for experimental craft (this is considered to be "experimental" category in the US and Canada), but yes, the idea behind an experimental is that everything is DIY. I have an experimental, and I can do close to anything I want. What I can't do is complain when my plane crashes because I installed a part that isn't fit for duty. I, as the owner and operator, am the one that signs off on the airworthiness of the plane. E.G. If I install a Cessna part on my plane, and that is the cause of a crash, that is my fault from the point of view of the FAA. There may be legal considerations outside of airworthiness and flight rules, but as far as the FAA is concerned (or would be if this had happened in the US), the manufacturer of a part is off the hook once the thing is installed on an experimental.

elicash 11mo ago

In what way is this like vibe-coding -- or do you just mean both are bad? According to the report: > 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 – acrylonitrile butadiene styrene) filament material, with a glass transition temperature3 of 105°C. https://assets.publishing.service.gov.uk/media/69297a4e345e31ab14ecf6e9/Cozy_Mk_IV_G-BYLZ_01-26.pdf https://assets.publishing.service.gov.uk/media/69297a4e345e3... Isn't this simply a part that shouldn't have been allowed to be sold based on it being both faulty and also misleading?

johnnyanmac 11mo ago
The implication was that the part took shortcuts and made something that only looked good on the surface. But couldn't stand up to deeper scrutiny.
hbrav 11mo ago
Well how confident would you be that this part isn't exposed to temperatures above that glass transition temperature? It is installed near the engine.
- film42 11mo ago
  Installed _on_ an engine that operates at 200ºC!
- plorg 11mo ago
  The report further states that the part included in the original design (part of the kit) was made of a carbon fiber composite where the epoxy had a listed glass transition temperature of 84⁰C. If there is an element to be critical of along these lines it's that the part as originally designed is supposed to include an aluminum tube at one end that may stiffen the part - the report makes no conclusions whether it truly would have, but notes that the actual glass transition temperature was found to be much lower than listed, and lower than that of the epoxy used in the original design.
11mo ago

carabiner 11mo ago

Vibe coding can make code that is suitable for production. 3d printed plastic can not be a substitute for a fiberglass-metal part.

shmeeed 11mo ago
It absolutely can. Not all 3D printing is kids' toys. In the end it depends on the application. Vibe coded flight management systems, anyone?

sho_hn 11mo ago

I think a more useful definition of vibe coding is "something you can do when it really doesn't matter". Which requires a hell of a lot of judgement to know when it doesn't. Installing life-critical parts of shoddy engineering into a vital system of your airplane is a good example of when things do matter.

phkahler 11mo ago

>> This part could have likely been fine if it used a different material such as Ultem. Maybe, but FDM printed parts are still much weaker than molded parts. We tried printing some coolant pump housings once during development. They worked fine until the pressure went up and then layers separated and someone got to clean the lab. At least an air intake is gonna have negative pressure which might help hold the layers together.

PunchyHamster 11mo ago
but it didn't fail because of stress. It failed exactly because it was made from wrong material. If the exact same part was injection molded from the same material it would melt too

itopaloglu83 11mo ago

It’s also a validation failure as well, because somebody assumed that the 3d-printed part could work as intended without validating it under various use-cases and situations. Looks like they would like to make the early flight mistakes themselves instead of following air worthiness guidelines.