A Cozy Mk IV light aircraft crashed after 3D-printed part was weakened by heat

Post by carabiner » Thu, Dec 04, 2025, 10:11 PM UTC

fudged71 wrote: post #27

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.

Post by ncr100 » Thu, Dec 04, 2025, 10:12 PM UTC

elicash wrote: post #57

fudged71 wrote: post #27

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.

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°…

Post by pennomi » Thu, Dec 04, 2025, 10:12 PM UTC

zkmon wrote: post #83

I hope 3-D printing becomes obsolete when robots can achieve the same efficiency with using the standard construction materials. That should take away all benefits of 3-D printing over regular builds.

Post by zuppy » Thu, Dec 04, 2025, 10:13 PM UTC

brovonov wrote: post #19

CarVac wrote: post #2

I wonder what material it was printed with. edit: It was ABS-CF, which shouldn't be used under stress long-term in higher temperatures than maybe 65-70°C, or lower depending on the blend.

Lower, according to the report "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 52.8°C, and 54.0°C for the second sample" Yeah, they might have used ABS-CF filament, but unless they got it from a good brand that uses good resin and…

Post by Ntrails » Thu, Dec 04, 2025, 10:15 PM UTC

serf wrote: post #82

Treegarden wrote: post #64

Earlier quoted context omitted.

I think by vibe coding he means taking these things at face value instead of rigorously looking if they are up to the standard. When coding you would rigorously look if the code is good / produces any bugs. With vibe coding, you give a prompt and just accept the output, which might be full of errors and blow up (or melt). The analogy is that, yes you can print airplane parts, but they were sloppy and just accepted th…

>I think by vibe coding he means taking these things at face value instead of rigorously looking if they are up to the standard. Yeah, exactly -- which is why it's a stupid phrase for what happened here. Not every negligence is somehow equatable to an AI pitfall, it's just on parents' mind so it's the only metaphor that gets applied. A poorly fit hammer in a world of nails. I say this as an engineer/proprietor with y…