High radio frequencies (HF) between 3 and 30 MHz used for air-to-ground voice communication in overseas operations.
Source FAA Pilot/Controller Glossary · checked 2026-08-25
High radio frequencies (HF) between 3 and 30 MHz used for air-to-ground voice communication in overseas operations.
Source FAA Pilot/Controller Glossary · checked 2026-08-25