Airfoil Data
E266

The EPPLER 266 AIRFOIL is a 11.9% chord-thickness airfoil with a maximum camber of 5.9% at 40% 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 -5.9°.

Thin airfoil theory predicts a stall angle near 11.6° and a peak lift-to-drag ratio around 69 at typical UAV and light-aircraft Reynolds numbers — useful benchmarks before running a full XFOIL or NeuralFoil polar. The 12% thickness provides structural depth for main-spar placement without excessive drag penalty at moderate speeds.

The E266 appears in the wing design of at least 2 documented aircraft — notably by Schempp-Hirth. Its proven track record across canard designs makes it one of the more field-validated profiles in the UIUC database.

Designers evaluating the E266 typically compare it against profiles of similar thickness: NACA 2-H-15 AIRFOIL, FX S 03-182 AIRFOIL, FX 66-S-161 AIRFOIL, RAF 69 AIRFOIL, EPPLER 1200 AIRFOIL. The RAF 89 AIRFOIL is another reference profile frequently considered alongside it.