14 CFR § 91.709

Departure is from an international airport of entry designated in § 6.13 of the Air Commerce Regulations of the Bureau of Customs (19 CFR 6.13); and

In the case of departure from any of the 48 contiguous States or the District of Columbia, the pilot in command of the aircraft has filed—

A DVFR or IFR flight plan as prescribed in § 99.11 or § 99.13 of this chapter; and

A written statement, within 1 hour before departure, with the Office of Immigration and Naturalization Service at the airport of departure, containing—

All information in the flight plan;

The name of each occupant of the aircraft;

The number of occupants of the aircraft; and

A description of the cargo, if any.