Airfoil Data
NN7MK20

The NN7 MK20 is a 11.3% chord-thickness airfoil with a maximum camber of 5.7% at 37% chord, suited to general-aviation and UAV wing design. At zero angle of attack the cambered geometry generates positive lift, giving an estimated zero-lift angle of -5.7°.

Thin airfoil theory predicts a stall angle near 11.6° and a peak lift-to-drag ratio around 67 at typical UAV and light-aircraft Reynolds numbers — useful benchmarks before running a full XFOIL or NeuralFoil polar. The 11% thickness provides structural depth for main-spar placement without excessive drag penalty at moderate speeds.

Designers evaluating the NN7MK20 typically compare it against profiles of similar thickness: FX S 02/1-158 AIRFOIL, MH 84 13.69%, NACA 4415, EPPLER 855 AIRFOIL, FX 79-W-151 A. The GOE 535 AIRFOIL is another reference profile frequently considered alongside it.