What does 'SFC' denote on a chart regarding airspace numbers?

The designation 'SFC' on a chart refers to 'Surface,' indicating the lowest limit of airspace that extends from the ground up to a specified altitude. It is essential for understanding how airspace is structured and where various regulations apply. For example, when you see 'SFC' on a chart concerning airspace limits, it typically denotes the surface of the earth as the starting point for that specific airspace classification.

Recognizing 'SFC' as 'Surface' is critical for pilots and drone operators alike, as it impacts decisions related to altitude limits, adherence to airspace restrictions, and operational planning. Understanding this term aids in comprehending the broader structure of airspace management, which plays a significant role in ensuring safety and compliance with Federal Aviation Administration (FAA) regulations.