There is an interesting, to me, thread (A Vortex Tied in Knots) on Linked In that I would like help with.
http://us-mg6.mail.yahoo.com/neo/lau...=3c5fr5433t04p
The link mentions that the wing tip trailing vortex may convert from a straight line vortex to a series of ring vortices under certain conditions. I have seen this happen during an airshow demonstration; specifically at OSH about 5 years ago during a Hawker Harrier routine, I believe, with wing tip smoke at the bottom of a loop. What I am looking for is photo documentation that this can or does occur. Any additional information or assistance would be appreciated. Please help spread the word. Also, I would like a schedule for the Harrier bookings.