Airfoil Data
E403

The EPPLER 403 AIRFOIL is a 9.5% chord-thickness airfoil with a maximum camber of 4.7% at 43% 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 -4.7°.

Thin airfoil theory predicts a stall angle near 11.7° and a peak lift-to-drag ratio around 62 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.

The E403 appears in the wing design of at least 2 documented aircraft — notably by Bolkow. Its proven track record across canard designs makes it one of the more field-validated profiles in the UIUC database.

Designers evaluating the E403 typically compare it against profiles of similar thickness: GOE 682 AIRFOIL, GOE 496 AIRFOIL, GOE 282 (DAIMLER XIII) AIRFOIL, P-51D ROOT (BL17.5) AIRFOIL, FX 61-140 AIRFOIL. The Dayton-Wright 6 is another reference profile frequently considered alongside it.