Andrew's Challenge - Not an aircraft, but you can see where it's been!

Bit late with this, but I've had a few problems with a recent upgrade
to Vista.

This is not my photo, but a frame from a 16mm movie in the late '60s -
part of a Sydney University study into wingtip vortices. A professor
there had a theory that a single vortex from each wingtip did not have
sufficient energy, and that there should be a small contra-rotating
vortex in the centre. Our Hercules squadron (No37 at RAAF Richmond)
was authorised to fly a number of low level passes along the runway
near this tower with a smoke canister, while the University crew
filmed the result.

These flights were conducted over several days, early in the morning
while the air was still calm. For most, the results were
disappointing - only the basic vortex appeared. However, on this
flight the inner vortex is clearly visible. In the movie it was
spectacular.

Mike

--
Mike Mackenzie (AVCOM Services)
Brisbane, AUSTRALIA
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