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This glossary is written for virtual airline and flight simulation use within Virtual Air Canada Airline. It is not intended as a real-world aviation reference.
High Frequency radio refers to the band of radio frequencies between 3 and 30 MHz used for long-range voice and data communications in aviation. Unlike VHF, which relies on line-of-sight propagation and is limited to roughly 200 nautical miles, HF signals bounce off the ionosphere and can reach thousands of miles, making HF the primary communication method for oceanic and remote area operations. Aircraft crossing the North Atlantic, Pacific, or operating over polar routes depend on HF to maintain contact with oceanic area control centers when beyond VHF range. HF communication has practical limitations: the ionosphere changes with time of day, season, and solar activity, meaning a frequency that works well in the morning may be unusable by afternoon. Pilots and controllers use selcal (selective calling) to manage the constant static and background noise by alerting the crew only when a ground station is calling their specific aircraft. HFDL (HF Data Link) supplements voice communications with digital messaging over the same frequency bands, improving reliability for ACARS-type transmissions on oceanic routes.

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In Virtual Airline Operations

In flight simulation, HF radio is relevant when flying oceanic routes such as the North Atlantic Tracks on Virtual Air Canada Airline. Some simulators and add-ons model HF communication through networks like VATSIM or POSCON, where controllers may staff oceanic positions requiring HF-style position reports. Understanding HF procedures, including position reporting formats and selcal monitoring, improves realism on long-haul international flights.
  • ACARS - Aircraft Communications Addressing and Reporting System
  • SELCAL - Selective Calling System
  • NAT-HLA - North Atlantic High Level Airspace