This is in reference to: Failed 3D Printed Part Brings Down Small Plane | Hackaday
In short: A plane crashed due to a CF-ABS Duct which overheated and experienced deformation.
As I have done this type of project many times and have an understanding of AM polymers. I want to address some issues, so you don't make the same mistakes.
A) Not all filaments, regardless of name, are equal. This filament failed at ~54C instead of the idealistic 100C. There is a reason that Bambu and Creality and Prusa can print big ABS parts, plasticizers. These are additives specific to help the printing process, with the downside generally being degradation of the mechanical properties.
B) Read the TDS. If a filament does not have a TDS, it is probably not suitable for a structural application. Refer to A) not all filaments are equal.
C. Leave a safety net greater than 20C for amorphous polymers. Even if this filament had a TDS for 100C, I would not use it above 80C (it referenced 84C). It is already past what I would use in normal operating conditions
D. We are also ignoring FST (flame, smoke, toxicity). In projects I have done, we use self-extinguishing polymers. These polymers are subject to vertical burn testing to ensure that they will not spread a fire if one happens. While not a cause this incident, it is something that should not be ignored.
Recommendations:
A) ULTEM: easiest choice is ULTEM 9085, this material I would use up to 140C+ and has self-extinguishing characteristics. It is the defacto standard for FDM printing in Aerospace. It meets FAR25.853 for the interior of commercial aircrafts.
B) PEKK: fits the same general narrative as ULTEM, with a caveat it is more expensive (but easier to print).
C) PC-FR: I wouldn't want to use this material, but from a reputable vendor it should meet all the requirements. The deflection temperature should be around 120C and it's self-extinguishing. It's going to be much cheaper (the duct on my header page is PC).
Processing these materials requires a specialized printer capable of higher temperatures to print a part of substantial size. These printers are essentially ovens with printers inside. The excess cost of leveraging a partner to produce a part is nothing compared to the damage below.
The aftermath of using a budget material.