There was an incident some years ago where an EP-3R recon plane was forced to land by PLA fighters. Flight crew had a few mins to destroy critical components but the Chinese gathered some tech from that incident. Also, the unlucky Gary Powers.
I won't necessarily say the landing was forced by PLA fighters; that would imply PLA intentionally did this (to obtain tech?) while in fact that J-8 crashed and its pilot was killed/missing. US recon planes fly near China's (and other countries') coastal line with PLA's fighter near by all the time.
My point is that incident looks more like an accident to me even though China may have gained some tech out of it while losing one pilot and plane.
https://en.wikipedia.org/wiki/Mig-25#Western_intelligence_an...