Modification to meet Stage 3, Stage 4, or Stage 5 noise levels

This regulation provides an exception that allows certain noisy aircraft to fly into the contiguous United States even when they would normally be banned under noise rules. Specifically, if you have an older, louder airplane that doesn't meet Stage 3, 4, or 5 noise standards and is therefore prohibited from operating in the lower 48 states, you can apply for a special flight authorization to bring it into the country for the specific purpose of getting it modified to meet those quieter noise standards.

This matters because without this provision, you'd face a catch-22: your airplane is too loud to legally fly to a U.S. facility where it could be made quieter. The special authorization lets you ferry the aircraft to a maintenance facility for noise-reduction modifications, after which it can operate normally if it meets the required 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.*