The sad thing is that we are even talking about this. This is a SPORT for FUN. I know it's fun and seems very benign, but when you really think about it flying in such close proximity is dangerous. I'm not talking about a 16oz zagi flying 2 feet off the deck doing fly bys but even those with 1/4 and 1/3 scale cubs doing fly-bys down the center of the runway, hello, I'm 10 feet from your wingtips man! Even more dangerous as that as I'm flying my attention is not on the plane dangerously close to me but my plane out there. I can't watch both at the same time and therefor need some assurances that there will be some sort of warning before a plane gets too close. At our field we call "coming in", "going out", "deadstick", etc. to signal a plane is on or will be on the runway. Other than that you should be away from it at least enough to not inhibit normal traffic patterns. If the flyers enjoy watching you fly at least say "no one minds me taking it up for a few minutes, do they?" and I'm sure everyone - me including - will sit back and enjoy from a safe distance (under the shade of our awning!)