14 C.F.R. § 91.707 Flights between Mexico or Canada and the United States.
Title 14 - Aeronautics and Space
Unless otherwise authorized by ATC, no person may operate a civil aircraft between Mexico or Canada and the United States without filing an IFR or VFR flight plan, as appropriate.
Title 14: Aeronautics and Space
PART 91—GENERAL OPERATING AND FLIGHT RULES
Subpart H—Foreign Aircraft Operations and Operations of U.S.-Registered Civil Aircraft Outside of the United States; and Rules Governing Persons on Board Such Aircraft
§ 91.707 Flights between Mexico or Canada and the United States.
