14 CFR § 121.685
Aircraft record: Domestic and flag operations
July 13, 2020
Each certificate holder conducting domestic or flag operations shall maintain a current list of each aircraft that it operates in scheduled air transportation and shall send a copy of the record and each change to the responsible Flight Standards office. Airplanes of another certificate holder operated under an interchange agreement may be incorporated by reference.
[Doc. No. 28154, 61 FR 2615, Jan. 26, 1996, as amended by Docket FAA-2018-0119, Amdt. 121-380, 83 FR 9172, Mar. 5, 2018]