There's been a bit of confusion recently as to the requirements and minimum distance for entering flights into the Avon league. In a nutshell it's as follows: if you want to submit a flight other than a straightforward open distance flight (ie. no turnpoints) then the minimum distance (before any multiplication factors - ie. three for an FAI triangle) is 15km and you must submit a GPS tracklog. For open distance flights the minimum distance is 5km and there is no requirement to submit a tracklog (though you're welcome to of course).

As to how to submit your tracklog, you need a piece of software called GpsDump which will download your tracklog from your GPS and optimise your flight eeking out the maximum distance. Full details on the pgcomps.org.uk website here.