Communication and navigation equipment for overwater operations

When flying over water more than 30 minutes or 100 nautical miles from shore, aircraft operating under Part 91 Subpart F (large and turbine-powered multiengine airplanes) must carry redundant communication and navigation equipment. This means two transmitters, two microphones, two headsets (or one headset and speaker), two independent receivers, and two independent electronic navigation units capable of meeting ATC requirements.

"Independent" means one unit's failure won't affect the other's operation. A single radio that handles both communication and navigation can count for both requirements.

Exceptions allow ferry flights for repairs with one inoperative item, and when both VHF and HF are required, only one HF radio is needed if two VHF radios are installed. Special provisions permit reduced navigation equipment in certain Gulf of Mexico, Caribbean, and western Atlantic areas when using long-range navigation with expected VHF coverage gaps under 30 minutes.

"Shore" means land above the high-water mark.

*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.*