I think many of us would agree that getting lofted in a thermal is
theorectically possible, after all, thousands of paragliders and hang gliders
do this routinely every week worldwide and have done for decades. Lots of us
have kites with lifting areas near equivalent to hang gliders and
paragliders, so what is the real difference in a thermal? Of course smaller
kites could be just as dangerous in similar thermal conditions. I believe
the reports of this incident myself. More importantly, if kitesurfers aren't
aware of the possibility of this happening and the circumstances that may
cause it, it is almost guarenteed to happen again. Next time possibly
without the happy ending.

Repeating what we know and think at this point for those that missed the
earlier thread on thermals or could do with reminding:

Thermals are abundant, often violent and extremely powerful in Florida, in
many other parts of the US and world in general. Desert and arid areas, Cabo
Verde, parts of Hawaii, Baja, no doubt parts of Oz and many other prime
kitesurfing destinations have frequent, very strong thermals. When hang
gliding we look for them aggressively as they can maintain your flight time
indefinitely as long as you can keep running into them. Hang gliders are
designed for stable, safe flight for extended periods of time as well as
dealing with violent thermals, unfortunately kitesurfing kites are not. Any
of us who have messed up a jump in mid air, stalled the kite and fallen like
a rock can testify to that.

Thermals are usually invisible, rising columns or bubbles of warm or hot air
generally 100 typically to 300 feet in diameter. So you could be lifted in a
thermal and fall out of it and down suddenly, happens all the time to hang
gliders. In Florida, the upward lift on hang gliders in thermals ranges
typically from 200 to in excess of 700 feet per minute (FPM). In arid areas
thermals in excess of 1000 FPM can
occur. Now the interesting part, larger kitesurfing kites begin to
approximate the wing or lifting area of hang gliders. I haven't checked yet,
but I suspect that my AB 16.4 m exceeds the area of most hang gliders. Now a
kitesurfing kite won't have the lifting efficiency of a hang glider but I
suspect it comes close enough under certain circumstances. So what!?

The point of all this is, that under certain circumstances it is possible and
perhaps even likely, that kitesurfers could get lifted hundreds of feet in
thermals. This happened in Oahu in June, 2001 with tons of witnesses
including the media at a kitesurfing competition. Generally this will be over
the land as thermal generation over water is normally weak. If you are
kitesurfing on an offshore wind day, then the risk still applies as the
thermals will generate over land and blow
offshore.

So why isn't this happening all the time? Who knows but the potential for a
few very serious, likely terminal accidents a year exists. For those of us
that go in the ocean in onshore winds, don't loiter on the beach with kites
in the air MAY, theoretically be at low risk of experiencing this. For
people that launch inland at lakes, rivers, for playing around, maybe even
kiteskiing (you can get strong thermals in snow), they are at risk. Thermal
generation is often associated with dark fields,i.e. parking
lots, large
sandy areas, rising masses or high ground i.e. hills, mountains or CONDOS OR
OTHER TALL BUILDINGS (?), clear skies with bright sun, cold fronts with high
pressure systems. Other likely thermal collectors to stay away from include
large groups of trees, hot asphalt with cars, crop fields, etc. essentially
any large and dark area which can trap air prior to the breeze becoming
strong enough to cause penetration and allow mixing. In short, from pretty
commonly occurring conditions particularly inland.

So if you kitesurf inland or near prime thermal generating conditions along
the ocean, what do you do? To be honest I am not sure, be very careful and
selective at when to fly at a minimum. Trying to understand your local
thermal generation characteristics through local hang gliders, paragliders,
sailplane pilots as fully as possible would be another recommended approach.

Thermals are always around us, but often at not real strong levels. It is
the strong ones that you have to watch out for while you are at risk. In a
small to moderately sized lake or river this could be the entire time you are
out, including while on the water. I would be particularly careful if you
kitesurf on a lake in arid, desert-like conditions, say near the Great Salt
Lake, etc. Say you pop a nice jump near the windward shore and a thermal
comes along while you are in flight, up you go and where you come down could
be over land. Also, if you fly smaller kites are you safe? Maybe but I don't
think so, not in a strong thermal. It may not lift you hundreds of feet but
30 feet over land is enough to do serious harm. Some kitesurfers have
reported being lofted on relatively small kites in possible thermals already.

This sport is very new on a widespread basis. The ways of
interacting with the weather, e.g., lightening, sudden strong gusts, now
thermals, are only starting to become known, sometimes in very negative
ways.

Fly safe,
Rick



-----Original Message-----
From: mikes1p@... [mailto:mikes1p@...]
Sent: Sunday, July 15, 2001 10:16 AM
To: kitesurf@yahoogroups.com
Subject: [ksurf] Re: Scary Photo!!! - BUNK!!


I wasn't saying it didn't happen, all I was trying to say was the
photo looks doctored to me.

I've heard it was true from more than one source. One of the local
guys here was in Hawaii and heard about it the day it happened.

> Please don't open up a "Fake" discussion about this SERIOUS
kitemare!