Applicability

This regulation defines which aircraft and maintenance activities fall under Part 43's rules. Part 43 applies to:

• Aircraft with U.S. airworthiness certificates
• Foreign aircraft operating under Parts 121 or 135 in the U.S.
• All their engines, propellers, and components

Key exclusions: Experimental aircraft (unless they previously held a standard certificate), most light-sport aircraft operating under experimental certificates, and drones operated under Part 107 (with limited exceptions).

For light-sport aircraft with special airworthiness certificates, Part 43 applies but with relaxed paperwork requirements—you don't need to complete certain FAA forms or follow specific recordkeeping rules for non-FAA-approved products.

The regulation also covers life-limited parts removed from any type-certificated aircraft, ensuring proper tracking even after removal. This matters because it determines whether you must follow Part 43's maintenance and documentation requirements or can use alternative rules.

*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.*