Airfoil Data
A18SM

The A18 (smoothed) is a thin 7.2% chord-thickness airfoil with a maximum camber of 3.6% at 38% chord, suited to high-speed UAVs, sailplane tip sections, and propeller blade design. At zero angle of attack the cambered geometry generates positive lift, giving an estimated zero-lift angle of -3.6°.

Thin airfoil theory predicts a stall angle near 11.8° and a peak lift-to-drag ratio around 55 at typical UAV and light-aircraft Reynolds numbers — useful benchmarks before running a full XFOIL or NeuralFoil polar. The slim profile minimises pressure drag at higher speeds but leaves limited spar depth for structural integration.

Designers evaluating the A18SM typically compare it against profiles of similar thickness: GOE 368 AIRFOIL, NACA 65-410, Eiffel 10 (Wright) - 1903 Wright Flyer airfoil, GOE 494 AIRFOIL, NASA RC(5)-10 AIRFOIL. The EPPLER 584 AIRFOIL is another reference profile frequently considered alongside it.