Airfoil Data
FG4

The Fage & Collins 4 is a 12.7% chord-thickness airfoil with a maximum camber of 6.3% at 30% chord, suited to high-lift UAV wings, RC sailplanes, and low-Reynolds-number slow-flyers. At zero angle of attack the cambered geometry generates positive lift, giving an estimated zero-lift angle of -6.3°.

Thin airfoil theory predicts a stall angle near 11.4° and a peak lift-to-drag ratio around 70 at typical UAV and light-aircraft Reynolds numbers — useful benchmarks before running a full XFOIL or NeuralFoil polar. The 13% thickness provides structural depth for main-spar placement without excessive drag penalty at moderate speeds.

Designers evaluating the FG4 typically compare it against profiles of similar thickness: GOE 446 AIRFOIL, GOE 367 AIRFOIL, B-29 ROOT AIRFOIL, EPPLER 583 AIRFOIL, EPPLER 604 AIRFOIL. The SD8000-089-88 is another reference profile frequently considered alongside it.