Airfoil Data
NACA654421A05

The NACA 65(4)-421 a=0.5 is a 13.5% chord-thickness airfoil with a maximum camber of 6.7% at 40% chord, suited to high-lift UAV wings, RC sailplanes, and low-Reynolds-number slow-flyers. At zero angle of attack the cambered geometry generates positive lift, giving an estimated zero-lift angle of -6.7°.

Thin airfoil theory predicts a stall angle near 11.1° and a peak lift-to-drag ratio around 71 at typical UAV and light-aircraft Reynolds numbers — useful benchmarks before running a full XFOIL or NeuralFoil polar. The 13% thickness provides structural depth for main-spar placement without excessive drag penalty at moderate speeds.

Designers evaluating the NACA654421A05 typically compare it against profiles of similar thickness: GOE 679 AIRFOIL, FX 76-MP-120, AH 95-160, GOE 628 AIRFOIL, FX S 02-196 AIRFOIL. The NACA 63-206 is another reference profile frequently considered alongside it.