You may learn that this is a problem in your solution when you plot sections in GSView and see a straight line between the leading edge and trailing on one side and the curved edge on the other. Duplicate your input and reverse the sign for the y-values for the second half of the list. This way you will have the whole airfoil represented. Ideally data would be ordered from the Trailing edge around the leading edge and back to the trailing edge on the opposite side.
