I was standing right under the approach path at Lakeland Linder (during
the Sun N Fun fly-in) when a DC-9 landed. 20 seconds or so later, after
the jet noise faded, you could hear the vortices it left behind. It
sounded like someone was tearing apart a bedsheet the size of a football
field. Then, the vortices descended to ground level and whipped up twin
horizontal tornados of the fine grey sand they have down there. Tents
flapped and towels shook in the wind, and after a few more seconds it all
faded away.

We used to watch airliners land at Milwaukee's Mitchell Field (now Mitchell
International). When the wind was right, you could park right beneath the
approach path, and they'd go right over our heads, maybe 100 feet off the
ground.

The ripping sound made by their wingtip vortices was really amazing, just as
you describe. They would swirl all around you, long after the plane was
gone.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"