Aircraft certification and equipment requirements

This regulation establishes which aircraft types Part 121 air carriers can operate based on certification date and category.

General rule: Aircraft certificated after June 30, 1942 must be transport category and meet specific performance requirements in §121.173.

Special cases:

• Pre-1942 aircraft: Must meet either §121.173(c) or specific historical performance standards
• C-46 aircraft: Have unique requirements depending on whether carrying passengers or cargo, with cargo operations allowed for non-transport category C-46s under 48,000 pounds if they meet appendix C requirements
• Commuter category: Aircraft certificated between 1964-1995 in commuter category may operate if meeting §121.173 requirements
• Normal category: Limited exceptions exist for certain normal category aircraft manufactured before March 20, 1997, that meet additional airworthiness standards
• New aircraft: Any airplane with type certificate application submitted after March 29, 1995 must be Part 25 transport category

This ensures Part 121 carriers operate aircraft meeting appropriate safety and performance standards.

*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.*