it was a microlight flight booked to view some crop circles.
the flight leaves from near cherhill, heads over cherhill down/oldbury, sweeps past west kennet barrow, over wansdyke and milk hill, into the vale of pewsey before heading back. about 20mins and £60!
unfortunately the guy has difficulty in getting permission to flyover avebury due to MOD restricted airspace (from nearby raf lynham)
www.wiltsmicrolights.com