The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter; indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases then go through a maximum and then decreases. consider an infinite wing with a naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9 × 106.