On Oct 21, 9:26*pm, "Bill Daniels" bildan@comcast-dot-net wrote:
You know, I've been flying FX 67-150 and -170 airfoils for years. *I've
smashed thousands of bugs, flown through many rain showers and even
collected substantial ice on occasion yet I've not seen any unusual
performance degradation when analyzing flights with SeeYou nor did I feel
any in flight. *In fact, those glides with crappy wings often show a
height/distance ratio well above the published L/D. *I know Bob Faris gets
great results with his LS-3a in the same conditions. *I wonder if these
airfoils are getting a bad rap.

Bob Faris flies an LS-3, which is rather different than an LS-3a in
the flap/aileron vs flaperon and wing weight areas. Read something in
the past year that suggested that the FX67/170 and 150 did not degrade
on long spans where the thickness was 15%, but can't find it at the
moment.

Frank Whiteley