Yes I DO. As one of the Safety Officers I can (we have 3).

But the problem is If I say NO, they will probably just come back during the week while I am not there. Then you have someone with a questionable plane FLYING ALONE.

95% of R/C'ers use common sense. The few that are clueless, are the problem. Usually a few quiet words and they will take the plane home and make changes.

It is the few you need to watch out for. I try to check out visually first. But there are things you can't really see (i.e how many times have the radio/servos been crashed.)

The few (2) in our club sometimes take advice, other times you get "I know better." Then it is judgement call as to the SAFEST response.

If I see someone knowingly fly anything unsafe, I will step in. Usually others will beat me too it. This is a great club.