Find official aviation HF frequency charts and learn how to select by route and UTC, tune the radio, make a call and handle no contact.
In Aviation & Real-World Flying, HF frequencies should be taken from the applicable state AIP, oceanic or remote-area communications charts, and valid NOTAMs—not a generic worldwide list. Choose the frequency family for the route, control area and UTC period, then use the assigned primary frequency with any published or assigned secondary ready.
Where are aviation HF frequency charts published?
Official aeronautical information for the airspace is the primary source, although HF details may appear in communications tables rather than on a conventional route chart.
| Source | What it provides | What to check |
|---|---|---|
| State AIP | Ground stations, call signs, frequencies, coverage and operating hours | Look in the communications or en-route sections; the exact AIP section varies by state |
| Oceanic or remote-area procedures | Frequency families, network sectors, primary and secondary channels, and reporting procedures | Confirm that the document covers the correct OCA, FIR or remote region |
| AIP amendments, supplements and NOTAMs | Frequency changes, outages and temporary restrictions | Match the validity period to the planned flight in UTC |
| Operational briefing or ATC assignment | The frequencies actually assigned for that crossing or sector | An operational assignment normally takes precedence over the planning chart |
Use the official aeronautical information portal of the state responsible for the airspace. Search its AIP for terms such as HF communications, air-ground communications, oceanic communications, frequency families or voice communications. Our practical explanation of chart types, legends and communications entries covers the general chart-reading skills needed here.
A telecommunications spectrum-allocation chart is not an operational aviation HF chart. It shows which services may use a band, but it does not identify the correct aeronautical station, sector, hours or calling procedure.
What information does an HF communications chart show?
An aviation HF chart links each frequency to a defined station, service, geographical area and period of use.
- OCA, FIR or network: The oceanic control area, flight information region or remote communications network covered.
- Station and call sign: The radio station to call. This may be an aeronautical communications operator relaying messages rather than the controller handling the flight.
- Service: ATC voice, flight information, weather broadcast or company communications. A receive-only VOLMET broadcast, for example, is not a frequency to call.
- Frequency or family: One channel or a group of channels intended for a particular route network. Some publications use terms such as MWARA or RDARA for major, regional and domestic air-route areas.
- UTC hours: Scheduled operating hours or time bands used to select a family. Check the UTC date as well as the clock when crossing midnight.
- Remarks: Coverage limits, primary and secondary use, SELCAL arrangements or restrictions on the type of traffic accepted.
HF frequencies are commonly printed in kHz, while a radio may display MHz. Divide kHz by 1,000: 5500 kHz becomes 5.500 MHz. Treat that as a unit-conversion example, not as an operational frequency.
How do you select and use the correct HF frequency?
- Identify the airspace and service. Mark where the flight leaves VHF coverage, which OCA or FIR applies, and whether the required service is ATC voice, weather or company communications.
- Verify the publication. Check the chart or table effective date, incorporated amendments and NOTAMs valid for the flight. A saved crew card or old simulator chart can retain a plausible-looking frequency long after it has changed.
- Select the published family. Match the route, region and UTC time band. Lower HF frequencies often propagate better at night and higher ones in daylight, but this is only propagation guidance; it does not override the published family or a station assignment.
- Tune the HF set correctly. Use the aircraft's HF control head rather than a VHF COM radio. Aeronautical HF voice normally uses upper sideband, although many installed sets select the mode automatically. Select the correct audio and microphone source and allow any antenna-coupler tuning cycle to finish.
- Listen before calling. Confirm that the channel is not occupied, then use the published station call sign, aircraft call sign and concise request. Position reports, radio checks and SELCAL checks must follow the procedure for that region.
- Retain the backup. Record the primary and secondary channels where the crew can retrieve them quickly. A successful SELCAL check may reduce continuous listening where procedures permit, but it does not cancel required communications or contingency duties.
Do not assume that a data-link connection makes the HF check unnecessary. On routes where HF is required as a backup, the crew still needs the assigned frequencies and the prescribed means of re-establishing voice contact.
What should you do if there is no HF response?
If the station does not answer, first check the radio setup and chart selection, then try the assigned secondary or another authorised channel in the same family according to regional procedures.
| Symptom | Likely check | Action |
|---|---|---|
| The radio rejects the entry | HF versus VHF control head; kHz versus MHz format | Use the installed HF set and the entry format specified in its operating instructions |
| No receiver noise or signal | Audio selector, volume, squelch, receiver selection and antenna coupling | Correct the setup using the aircraft checklist |
| Noise is present but nobody answers | Wrong UTC family, region, station or propagation conditions | Repeat once clearly, then use the assigned secondary or approved alternative |
| Other aircraft are heard but transmission fails | Microphone selection, push-to-talk routing or incomplete coupler tuning | Recheck the panel and report the failure by VHF or data link if available |
If contact still cannot be established, use the published communications-failure or oceanic contingency procedure. Do not sweep through unrelated frequencies and transmit calls at random. While still within VHF coverage, advise the controlling unit before proceeding into an area where HF is required.
Can HF frequency charts be used in a flight simulator?
HF charts can be used for procedural simulation only when the aircraft or communications system models HF tuning and voice support.
A normal COM1 or COM2 radio covers the VHF communications band and will not accept a 5–20 MHz HF channel. Some simulated aircraft display an HF control head without modelling usable communications, while others reproduce tuning, antenna coupling or SELCAL to varying degrees. An online voice client may also handle frequencies independently of the cockpit radio.
For the underlying tuning and microphone controls, see our guide to operating simulator COM and NAV radios. If the required channel is tower, ground, approach or ATIS rather than oceanic HF, use the workflow for finding airport VHF frequencies in charts, airport data and avionics.
Does an HF chart authorise you to transmit?
An HF chart is information, not permission to transmit. Real aeronautical HF transmissions require an authorised aircraft station, appropriately qualified crew and an operational reason to use the service; licensing and radiotelephony requirements depend on the responsible state. Simulator use creates no radio-frequency transmission unless separate transmitting equipment is involved.