Airfoil Data
LEGIONAIR140_SM
Legionair 140 (digitized and smoothed by MSelig)
Wing Geometry Simulator
The Legionair 140 (digitized and smoothed by MSelig) is a thin 7.7% chord-thickness airfoil with a maximum camber of 3.8% at 31% chord, suited to high-speed UAVs, sailplane tip sections, and propeller blade design. At zero angle of attack the cambered geometry generates positive lift, giving an estimated zero-lift angle of -3.8°.
Thin airfoil theory predicts a stall angle near 11.8° and a peak lift-to-drag ratio around 57 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 LEGIONAIR140_SM typically compare it against profiles of similar thickness: USA 41 AIRFOIL, DF102, DF 101 AIRFOIL, FX 84-W-097, GOE 276 (DAIMLER VII) AIRFOIL. The USA 51 AIRFOIL is another reference profile frequently considered alongside it.
Related Airfoils
Engineers evaluating the LEGIONAIR140_SM frequently compare it against profiles with comparable geometric constraints. Below are the closest matches based on maximum thickness (7.7%) and max camber (3.8%).