In article , K.P. Termaat
writes
For a distance flight using up to three turn points the Sporting Code says
at 1.4.5.b. : "The turn points must be at least 10 kilometers apart and may
be claimed once, etc."

Why "10 km", why "once". Does anybody know.

It was an arbitrary distance decided on by Tor Johannessen when he was
in charge of Sporting Code rules some years ago. The intention was to
prevent repeat use of a particular turn point. I was Sporting Code
editor (under Tor) at that time and argued against it, but did not
prevail.

After all, it is for a distance rather than a goal flight and I would
have though that if the required distance can be proved, that should be
sufficient. And even for a goal flight, what is wrong with a repeat
turn point as long as it is in the pre-flight declaration and the
geometry of the course is correct for the type of flight concerned?

However, I think that it is right that some rule prevents the use of
lots of repeat legs, or even lots of legs, in wave or ridge lift. That
was the purpose of the "up to three turn points".

Any figure, 10km or other, is arbitrary. A slight error, say 9.9 km
would lead to the whole flight being rejected whereas 10.1 km would be
OK. As you say, Karel, "why?"

Particularly now that free (no pre-flight turn point declaration) flying
for various distance records is allowed, perhaps the whole matter of
distance and goal definitions should be looked at again by IGC. For
instance, where "distance" is the criteria rather than "goal", why do
not free flight rules apply? And for free flights where waypoints can
be selected by the pilot after flight, why is a pre-flight declaration
needed at all?

Just a couple of "stones into the millpond" .........

--
Ian Strachan
Lasham Gliding Centre, UK

Bentworth Hall West
Tel: +44 1420 564 195 Bentworth, Alton
Fax: +44 1420 563 140 Hampshire GU34 5LA, ENGLAND