According to https://assets.publishing.service.gov.uk/media/69297a4e345e3...
> The aircraft owner [...] understood from the vendor that it was printed from CF-ABS (carbon fibre – acrylonitrile butadiene styrene) filament material, with a glass transition temperature of 105°C [...] he was satisfied the component was fit for use in this application when it was installed.
> [...] Two samples from the air induction elbow were subjected to testing, [...] The measured glass transition temperature for the first sample was 52.8°C, and 54.0°C for the second sample.
I've known 3D printing folks who run off a throwaway prototype in a cheap, easy-to-print material to check for fit before printing in more difficult, expensive materials. Easy to imagine a careless manufacturer getting the PLA prototype mixed in with the ABS production parts, and selling it by mistake.
Of course, the aviation industry usually steers clear of careless manufactures....