After the disappointing performance of the 1901 glider, the Wrights systematically tested dozens of model airfoils.

Question: Which one of the airfoils did they choose for the 1902 glider?

Answer: None of them!

The model airfoil designated as #12 was the most "dynamically efficient," performing better than all the others. However, as Wilbur informed Octave Chanute, "We never tested a surface corresponding exactly to those used in our 1902 machine.." (McFarland, pp 351-352).

Why?

The answer is unknown—there were many secretive aspects of their work which neither Orville or Wilbur ever recorded. Did the Wrights consider the design of the wing a secret? Or was the design an intuitive leap based on the work in the tunnel that simply never got written down? Regardless, neither of the Wrights recorded anything further about the 1902 design (Jakab, pp 151-152).