Use of certificated land airports in the United States

This regulation governs which airports Part 121 air carriers can use for scheduled passenger operations in the United States.

For domestic, flag, and supplemental operations (as specifically defined in the regulation based on aircraft size and route type), carriers must generally use airports certificated under Part 139. After 2005, these airports must also be classified to handle the specific aircraft type and operation being conducted.

Key exceptions allow carriers to:

• Use non-certificated airports as alternate airports for planning purposes
• Operate at U.S. Government airports that meet equivalent Part 139 safety standards
• For other passenger operations not meeting the defined operation types, use non-certificated airports if adequate, with additional lighting and wind information requirements for night operations

The regulation essentially ensures that larger passenger aircraft operating scheduled service use airports meeting federal safety and infrastructure standards, while providing flexibility for smaller operations and emergency planning.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*