14 CFR 121.663 : Aeronautics And Space (§ 1.1 To Parts 1311-1399) — (§ 110.1 To Part 199) — Federal Aviation Administration, Department Of Transportation (Continued) (§ 110.1 To Part 199) — Air Carriers And Operators For Compensation Or Hire: Certification And Operations (§ 110.1 To § 139.343) — Operating Requirements: Domestic, Flag, And Supplemental Operations (§ 121.1 To Appendix P To Part 121) — Dispatching And Flight Release Rules (§ 121.591 To § 121.667) — Responsibility for dispatch release: Domestic and flag operations.