Flight data recorders

This regulation requires Part 135 operators to install and use flight data recorders (FDRs) on certain turbine-powered aircraft based on passenger capacity and when the aircraft entered service.

Aircraft with 10-19 passenger seats added to operations after October 1991 need digital FDRs recording parameters from Appendix B or C, retaining at least 25 hours of data. Aircraft with 20-30 seats (airplanes) or 20+ seats (helicopters) have more extensive requirements under Appendix D or E, with the specific parameters depending on the aircraft's type certification date—older aircraft record fewer parameters than those certified after 1969.

The recorder must run continuously from takeoff to landing. Operators must preserve recorded data for at least 25 hours of operation (10 hours for rotorcraft under paragraph b), up to 60 days maximum, unless an accident occurs requiring NTSB notification—then the data must be preserved for at least 60 days. This ensures critical flight information is available for safety investigations and operational analysis.

*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.*