For the nice C310 under development by chad et.al. (thanks!) https://forum.flightgear.org/viewtopic.php?f=4&t=40501 there is a set of aerodynamic data available from NASA wind tunnel tests.
https://ntrs.nasa.gov/citations/19690007971
Copyright notice in the metadata of the document is: "Work of the US Gov. Public Use Permitted."
Is it allowable to use these data under GPL?
The general conditions https://sti.nasa.gov/disclaimers/ are of limited use to answer this question, at least for me.
It might have come out of fashion, but "found on the internet" does not mean, it can be done anything with it. Of course the source of the data will be mentioned as part of good opensource workmanship and respect for other's works. But in order to protect the project it would be appreciated to have more clearness here.
This question seems to be centered around the definition of "public use". But it is also valid for use of data from other publications by universities or similar, who might have other general conditions.
Kindly refrain from sidetracking this thread. Thanks in advance!