Compliance with approved routes and limitations: Domestic and flag operations.
CFR · 2024-01-01 · US · Title 14
No pilot may operate an airplane in scheduled air transportation— (a) Over any route or route segment unless it is specified in the certificate holder's operations specifications; or (b) Other than in accordance with the limitations in the operations specifications.
official document · source cfr-2024 · id 14:§ 121.555