On an FAA sectional chart, an airport symbol and data block printed in blue indicate that the airport —

Why: FAA-CT-8080-2H Legend 1 states, "Airports having control towers are shown in blue, all others in magenta." Blue airport symbols and data always mean the field has a control tower; magenta means it does not.

• Confuses airport color coding with runway-status symbols; a closed airport uses its own distinct runway symbol, not a color change.
• Assumes airport color indicates the surrounding airspace class, but color only distinguishes towered (blue) from non-towered (magenta) airports — airspace class is shown separately, by the boundary line style around the airport.