NACA 2421
       18.       18.

  0.000000  0.000000
  0.012500  0.038700
  0.025000  0.052100
  0.050000  0.070000
  0.075000  0.082900
  0.100000  0.092800
  0.150000  0.107000
  0.200000  0.115900
  0.250000  0.121500
  0.300000  0.123800
  0.400000  0.121600
  0.500000  0.112200
  0.600000  0.097900
  0.700000  0.079400
  0.800000  0.057400
  0.900000  0.031800
  0.950000  0.017600
  1.000000  0.002200

  0.000000  0.000000
  0.012500 -0.028200
  0.025000 -0.040200
  0.050000 -0.055100
  0.075000 -0.064800
  0.100000 -0.071800
  0.150000 -0.080500
  0.200000 -0.085200
  0.250000 -0.086700
  0.300000 -0.086200
  0.400000 -0.081600
  0.500000 -0.073100
  0.600000 -0.061700
  0.700000 -0.048700
  0.800000 -0.034400
  0.900000 -0.018800
  0.950000 -0.010600
  1.000000 -0.002200