INTRODUCTION
The NACA has for some time been investigation airfoils equipped with high lift devices for the purpose of improving the performance characteristier these airfoils. The result of tests of low-drag airfoil equipped with plain, split, or slotted flaps have been obtained with large-drag airfoils equippod with plain, split, or slotted flaps have been presented in reference 1.The results of references 2 and show that, on conventional air-foils, the lightest lifts have been obtained with large-chord venation-blind and double-slotted flaps. The present investigation was made to determine the lift, drag, and pitching-moment characteristics of a low-drag airfoil with a double-slotted flap at various flap deflections. In addition, the optimum position for maximum lift and flap path were to be found.