wrote:

The SC3 rule is:


"For the purpose of the calculation of FAI geodesic distances, the WGS84
earth model shall be used."

Yes - since 1st Oct 2002 - WGS 84 is the only method to be used for
soaring records (sphere remains in use in hang gliding)

And can anyone give me an example of a "non-critical" distance
measurement?

50 km badge if distance is 51 km or more.... the difference between
sphere and ellipsoid is less than 1 %. You may event measure on the map,
like in the good old times, when there were no GPS ;-) (remember the FAI
SC has been written in these times - that's why there is such odd things
like the requirement of overtaking the old record by more than 10 km)

But every good flight planning software* makes now the exact calculation
in WGS 84, so why not use it ?

*at least SeeYou, CouTraCi, in last versions - and if yours don't, there
is a html WGS84 distance calculator on IGC site http://www.fai.org/gliding

--
Denis
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