What must a carrier operating under 14 CFR Part 121 comply with?

• A. Only with Part 121 regulations
• B. Only with Part 91 regulations
• C. With both Part 91 and Part 121 regulations
• D. With no other parts of the Federal Aviation Regulations

Answer: (C)

Carriers operating under 14 CFR Part 121 are subject to a comprehensive regulatory framework that encompasses both Part 121 and Part 91 regulations. Part 121 provides specific requirements for operating large air carriers, including standards for airworthiness, maintenance, training, and operational procedures. Part 91 applies more broadly to general aviation and includes regulations that govern the operation of all aircraft, such as those concerning pilot certification, aircraft maintenance, and pre-flight actions.

By adhering to both sets of regulations, a Part 121 carrier ensures that it meets the rigorous safety and operational standards necessary for commercial aviation while also complying with the general aviation standards applicable to all aircraft operations. This dual compliance helps maintain safety, operational efficiency, and regulatory integrity in the aviation industry, reflecting the need for a multifaceted approach to aviation operations.