Airfoil Data
GM15SM

The GM15 (smoothed) is a thin 7.4% chord-thickness airfoil with a maximum camber of 3.7% 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 -3.7°.

Thin airfoil theory predicts a stall angle near 11.8° and a peak lift-to-drag ratio around 56 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 GM15SM typically compare it against profiles of similar thickness: GOE 417A (GEW. PLATTE) AIRFOIL, RG 8 AIRFOIL, EPPLER 817 HYDROFOIL AIRFOIL, HQ 3.5/8 AIRFOIL, EPPLER 485 AIRFOIL. The SG6043 is another reference profile frequently considered alongside it.