Airfoil Data
E637

The EPPLER 637 AIRFOIL is a 9.6% chord-thickness airfoil with a maximum camber of 4.8% at 28% 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 -4.8°.

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.

Designers evaluating the E637 typically compare it against profiles of similar thickness: GOE 285 AIRFOIL, GOE 167 (V.KARMAN PROP.2) AIRFOIL, RAF 6 AIRFOIL, FX 60-126/1 AIRFOIL, EPPLER 407 AIRFOIL. The USA 26 AIRFOIL is another reference profile frequently considered alongside it.