Airfoil Data
UI1720

The UNIVERSITY OF ILLINOIS UI-1720 AIRFOIL is a 11.5% chord-thickness airfoil with a maximum camber of 5.7% at 19% 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 -5.7°.

Thin airfoil theory predicts a stall angle near 11.6° and a peak lift-to-drag ratio around 68 at typical UAV and light-aircraft Reynolds numbers — useful benchmarks before running a full XFOIL or NeuralFoil polar. The 11% thickness provides structural depth for main-spar placement without excessive drag penalty at moderate speeds.

Designers evaluating the UI1720 typically compare it against profiles of similar thickness: EPPLER STE 87(-3)-914 AIRFOIL, AH 94-156, EPPLER 793 AIRFOIL, FX 62-K-153/20 AIRFOIL, MUE 139. The OAF128 AIRFOIL is another reference profile frequently considered alongside it.