Thanks for the replies, but don't you understand? My brain hurts!
Please E-X-P-L-A-I-N S-L-O-W-L-Y using theoretical terms though, so I've got something to "hang my hat on" as my Chief says.
As far as I can tell, using 10deg increases L more than it increases D, therefore increasing (L/D) both range and endurance. If my premise is wrong, explain my measurements some other way. Don't just rubbish it. For reference, I'm looking at Kermode (9th ed.) p. 176 in the 'Gliding and Landing' chapter. Can't find what happens to L/D as Fowler flaps are extended by 10deg intervals, which seems to be the crux of the debate.
Sorry for hijacking your thread GWHIZ
------------------
Confident, cocky, lazy, dead.