Applicability

This regulation defines where the flight rules in Subpart B of Part 91 apply. These rules govern all aircraft operations within the United States and extend to 12 nautical miles offshore from the U.S. coast.

In practical terms, this means that whenever you're flying over U.S. territory or its coastal waters (out to 12 nm), you must follow the specific operational rules contained in this subpart. These include regulations covering things like right-of-way rules, minimum safe altitudes, speed limits, and formation flight requirements.

The 12-nautical-mile boundary is significant because it defines U.S. territorial waters. Beyond this distance, you enter international airspace where different rules may apply. For most pilots flying domestically, this regulation simply confirms that standard U.S. flight rules apply throughout your normal operating area. The coastal boundary matters primarily for pilots conducting offshore operations or international flights.

*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.*