US-FAA14 CFR 71.9

Overlapping airspace designations

When different classes of airspace overlap in the same location, you must follow the rules of the more restrictive airspace class. This regulation establishes a clear hierarchy to eliminate confusion about which operating rules apply.

The restrictiveness ranking from most to least restrictive is:

Class A (most restrictive)
Class B
Class C
Class D
Class E
Class G (least restrictive)

In practice, this means if you're flying where Class D airspace overlaps with Class E airspace, you must comply with Class D requirements (such as establishing two-way radio communication). Similarly, if Class B airspace extends into what would otherwise be Class E, the Class B rules govern. This hierarchy ensures pilots always know which set of operating requirements, equipment mandates, and clearance procedures apply when airspace boundaries coincide.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*

This is an original plain-English explanation for training and reference, not legal advice and not for navigation. Always rely on the current official rule linked above. Last reviewed June 20, 2026.