Which part of the FARs deals with rules for air carrier operations?

Part 121 of the Federal Aviation Regulations (FARs) specifically governs the operation of scheduled air carriers and commercial operators flying large aircraft. This section outlines the requirements for operating air carriers that transport passengers or cargo under a certificate issued by the FAA. It includes detailed regulations regarding crew qualifications, maintenance standards, operational procedures, and safety measures.

Understanding the significance of Part 121 is crucial, as it ensures that air carriers operating under these regulations maintain a high level of safety and reliability in their services. The wide array of requirements also encompasses operational control policies, performance specifications for aircraft, requirements for training programs, and record-keeping for compliance audits.

While other parts pertain to different classes of air carriers, such as Part 135, which governs commuter and on-demand operations, they do not cover the extensive range of regulations that apply to the larger, scheduled operations defined in Part 121.