Explain the NACA airfoil naming convention.

The NACA 4-digit series (e.g., NACA 2412) encodes airfoil geometry: first digit is maximum camber as percentage of chord (2%), second digit is location of maximum camber in tenths of chord from leading edge (4 = 40%), last two digits are maximum thickness as percentage of chord (12%). The NACA 5-digit and 6-series provide additional design parameters. This standardized system allows engineers to quickly understand airfoil characteristics and select appropriate profiles for specific applications.