Hi Brian,

I tried out your latest update. Very nice. I see the error you found and can duplicate it. I determined it is indeed round-off error. Here are the arrays including the tangent points with as much precision as I can have with the tools available to me:

DATA AFXTAB
& /0.50D0, 1.250D0, 2.50D0, 5.0D0, 7.50D0, 10.0D0, 15.0D0, 20.0D0,
& 25.0D0, 30.0D0, 35.0D0, 40.0D0, 45.0D0, 50.0D0, 55.0D0, 60.0D0,
& 65.0D0, 70.0D0, 75.0D0, 80.0D0, 85.0D0, 90.0D0, 95.0D0,
& 0.2051137930D0, 99.981193170D0, 0.0D0, 0.5750D0, 100.0D0,
& 99.9790D0/
C
DATA AFYTAB
& /0.6880D0, 1.0650D0, 1.460D0, 1.9640D0, 2.3850D0, 2.7360D0,
& 3.2920D0, 3.7140D0, 4.0360D0, 4.2680D0, 4.4210D0, 4.4950D0,
& 4.4850D0, 4.3770D0, 4.1690D0, 3.8740D0, 3.5090D0, 3.0890D0,
& 2.620D0, 2.1170D0, 1.5940D0, 1.0690D0, 0.5440D0, 0.4402377380D0,
& 0.0208850310D0, 0.0D0, 0.0D0, 0.0D0, 0.0D0/

They do not have the one point I take off to have the curve fit work out. So at this point you have a couple of options you can follow. I compared what burrman did to what I did and the difference is small. I am fine with either one. They both make a nice solid with no ripples or any other distortions. Both deviate from the naca definition to make everything work out, as the naca definition contains some error. I am keeping the le and te radius definitions and relaxing the data points by using a curve fit. With burrmans method you can keep the data points using a control point spline and then modify the le definition. The te definition is fine as is.

Very nice work.

Anthony