I keep wondering if they were just doing a low approach fly-by, like many of us do. If that was the intent, what went wrong? The right wing tip was not damaged from hitting the runway but appears to have just broke off at the extended fuel cell attach point. If the fuel cell broke off while performing a fly-by at high speed this could roll the aircraft clockwise very quickly. One would expect that it may look similar to the reports that witness's described. If this is the case why did the fuel cell separate? High speed? Structural? We may never know.
Interesting story relating to the crash:
http://www.examiner.com/x-35334-Newa...illfated-plane