An airfoil is any surface such as a wing, propeller, or helicopter blade that generates lift when air flows over it. The airfoil is designed so that the airflow speeds up over the top surface, which decreases the air pressure and increases lift. The leading edge is the front part that air first meets, and the trailing edge is the back where the top and bottom airflow meet again. Spars, ribs, and stringers make up the basic wing framework, providing structure and shape. Early wings were wood but now aluminum and lightweight composite materials are most common.

1. Airfoils Reuben, Collin, Andrew

4. Designs of Airfoils