14 C.F.R. § 71.9 Overlapping airspace designations.
Title 14 - Aeronautics and Space
(a) When overlapping airspace designations apply to the same airspace, the operating rules associated with the more restrictive airspace designation apply. (b) For the purpose of this section— (1) Class A airspace is more restrictive than Class B, Class C, Class D, Class E, or Class G airspace; (2) Class B airspace is more restrictive than Class C, Class D, Class E, or Class G airspace; (3) Class C airspace is more restrictive than Class D, Class E, or Class G airspace; (4) Class D airspace is more restrictive than Class E or Class G airspace; and (5) Class E is more restrictive than Class G airspace.
Title 14: Aeronautics and Space
PART 71—DESIGNATION OF CLASS A, B, C, D, AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE ROUTES; AND REPORTING POINTS
§ 71.9 Overlapping airspace designations.
