Communicating with Stockholmradio


The key to successful and reliable HF Radio communications is not only reliant on geomagnetic conditions and equipment. Pilot skills and experience are also very important, when adjusting to the conditions that can quickly change during the flight.

Always consult our HF Propagation chart, before contacting Stockholmradio. Locate the graph on the Propagation Forecast that best corresponds to your position and choose the nearest Stockholmradio frequency. Be persistent when trying to establish contact on HF-radio. By persistently trying alternative frequency bands and repeating unsuccessful calls after a few minutes can significantly extend the approximate coverage area available.

What should I do if I don’t receive a response?

  • First, try to call again a couple of times on the same frequency.
  • Then, try another frequency.
  • Then, try again in 15-30 minutes. (It is more likely then that a change in aircraft position or conditions will result in successful contact).

HF radio should always be in USB-mode (Upper Side Band) and not in AM mode. The radio talk must be as clear and concise as possible to avoid any misunderstanding. Use short sentences, and where necessary repeat your message to ensure that it is received and understood. When contacting Stockholmradio, always provide the following information:

  • Flight number / Registration
  • Approximate geographic location
  • The HF frequency used to call

This will enable the radio operator to select a suitable transmitter and expedite good communications. Please allow 30 seconds for antenna positioning. Our operators at Stockholmradio listen for voice calls on six monitored kHz frequencies: 3494/23210, 5541, 8930, 11345, 13342, and 17916. The calls are audible on several directional loudspeakers with at least three loudspeakers for each frequency.

The SELCAL function of the HF-radio is important. We recommend that the pilot makes an initial SELCAL check with Stockholmradio when departing and remain on SELCAL Guard with Stockholmradio. It is not necessary to constantly listen to the noisy HF-frequency. The volume can be turned down, but not off. The pilot will then be alerted by an optical or acoustic signal when Stockholm Radio has traffic for him/her. The chosen frequency may sometimes only be good for a limited period during the flight as the contact frequency varies depending on the time of day and geographic location. We recommend that you periodically call Stockholmradio during the flight to check if it is necessary to choose a new frequency.

When Stockholmradio responds to a SELCAL check, our normal procedure is to send a message (via Type-B or Email) to your Operations/Dispatch advising them that the flight has Logged On to Stockholmradio and are contactable directly via SELCAL. Airlines that adopt this standard operating procedure rarely experience difficulties in contacting their flights through Stockholmradio. If SELCAL watch is not maintained on our frequencies, the crew may never be aware of Stockholmradio’s efforts to call them. Also neglecting to adjust the frequency selection for SELCAL watch during flight will result in degraded or unavailable Ground-to-Air HF contact. This is especially important for long haul flights.

Air-to-Ground calls under normal solar/geomagnetic conditions are usually the easiest to accomplish. The pilot selects a frequency from our HF Radio Propagation Forecast and Calls Stockholmradio.

Dispatcher or Airline Operation Control Center

We encourage dispatchers to always send a copy of the ATC Flight Plan to Stockholmradio, either by Type-B or AFTN. This will help the radio operator to quickly find important data related to your flight.

Please use the following address to send your ATC Flight Plan and related messages:

  • E-Mail:

Stockholmradio handles the following types of incoming messages:

  • FPL (ATC Flight plans, ICAO format)
  • MVT and MVA (Movements)
  • CHG (Change)
  • ARR (Arrive)
  • CNL (Cancel)
  • DEP (Departure)
  • DLA (Delay)

Read more


STORadio Pilot Training

STORadio Guide

General terms and Conditions

External links


Hourly radio propagation map

Daily radio propagation map

Propagation forecasts

AUG – OCT 2018 PDF

NOV 2018 - JAN 2019PDF

Monitored Frequencies

3494/23210, 5541, 8930, 11345, 13342 and 17916 kHz
USB - Upper Side Band

Contact STO Radio



+46 (0)8 601 79 10

Other Products

AVIOLINX · P.O Box 1242 · 131 28 Nacka Strand, Sweden · +46 (0)8 601 79 00 ·