Where can I find reliable data on maximum turn rates for jet fighters? I'm looking for reliable data on maximum instantaneous turn rates for jet fighters, something coming from reliable sources, ideally official flight manuals or specifications. I can't seem to find anything. I've seen reports of turn rates around 35°/s for some fighters (F-22, Typhoon, Rafale) but I don't know whether those can be trusted: https://defenseissues.wordpress.com/2014/01/11/comparing-modern-western-fighters/

If possible I'd like to have data on fighters with exceptionally high maximum turn rates, but really, anything would be welcome. Even information on old, retired fighters would be nice, and I guess that's more likely to be declassified. Failing that, a lower bound would be useful.

I don't know if turn rates make much sense for helicopters, but that information would also have some value.
Imformation on the F-22, particularly performance and mission systems data remains classified, as with the F-35 airplane.  To the best of my knowledge there isn't much technical data available to the public on those subjects.

Now flight manuals for older fighter aircraft are readily available to the general public.  PublicIntelligence.net is a great source for these documents, as they have them for the F-14, F-16, F/A-18E/F, AV-8B, A-10, just to name a few.

Janes/IHS is not a great source for this stuff; their entries are more on the level of intelligence briefs and encyclopedia entries and are not likely to contain the information you ar looking for.