The strange thing was that what litebulbs and I saw was the light a/c (I think a PA28) doing orbits and what looked like some pretty steep turns over the apron, not anywhere near the ILS beam at that range.
The a/c could have finished checking the ILS (which I assume would at some point involve flying an ILS approach at least in part) and the crew were maybe taking some pictures, or dare I say it, having some fun. It certainly looked like fun...