Numbers such as '55' shown above a horizontal line next to airport information on a sectional chart typically indicate:
Why →
In the standard airport data block on sectional charts, the number immediately following the airport name is often the field elevation in feet MSL. Runway length is shown as a separate number, typically with an 'L' suffix indicating lighting status. CTAF frequency is shown with a preceding symbol.The trap →
Field elevation, runway length, and frequency all appear in the same block and can be confused. The position and formatting distinguish them.SOURCE → FAA Aeronautical Chart User's GuideCHECKED APR 21ACS II.A.K5EASY