The Flytec 6030 (and Brauniger Compeo Plus) use the simpler FAI spheroid method for determining whether you are within the turnpoint radius or not (and thereby beeping at you), while the scoring system probably uses the WGS 84 Ellipsoid method. This can cause a problem. See here.

There are different methods to calculate distances on the earth’s surface. In paragliding and hang gliding sports two systems are used, the (older) FAI sphere and the WGS84 ellipsoid. The WGS84 ellipsoid needs more calculation power than the FAI sphere. Therefore the FAI sphere method is better suited for flight instruments; whereas, PC based flight evaluation software use the WGS84 ellipsoid.

The FAI SPORTING CODE, (SECTION 7D, CLASS O, HANG GLIDERS and PARAGLIDERS RECORDS and BADGES CLASSES I / II / III / IV / V, Effective: 1st May 2005) states that the preferred method is the WGS84 system. However, it doesn’t state that the FAI sphere isn’t valid anymore.

The differences for a 400m FAI radius are below 3m and generally there should not be problem, however, care must be taken in the case of larger radii.

In the situation where a competitor’s track shows them just barely missing the cylinder, the scorekeeper should not only rely on the WGS84 ellipsoid provided by CompeGPS Air Competition, but also on a FAI sphere calculation from Internet resources like http://williams.best.vwh.net/gccalc.htm

Furthermore, if a pilot believes that the scorekeeper has given a penalty for missing the cylinder by only a few meters, the pilot should file a protest and calculate the distance with the calculator above.

FAI/CIVL should clearly state what calculation method(s) will be accepted and should also state the tolerances that will be accepted or the procedure for scorekeepers in the event of a discrepancy between CompeGPS and the pilots flight instrument