Airfoil Data
E398

The EPPLER 398 AIRFOIL is a 12.0% chord-thickness airfoil with a maximum camber of 6.0% at 38% 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 -6.0°.

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.

Designers evaluating the E398 typically compare it against profiles of similar thickness: FX 61-184 AIRFOIL, EPPLER 1214 AIRFOIL, GOE 405 AIRFOIL, GOE 567 AIRFOIL, DAE-31 AIRFOIL. The HQ 2.1/9.5 AIRFOIL is another reference profile frequently considered alongside it.