Short Wave Listening (SWL): Major World Air Route Area (MWARA)
I'm located in Florida so most of my listening focuses on the
North Atlantic (NAT) portion of the MWARA aeronautical system.
These frequencies carry radio traffic between international
flights and ground control stations.
Modulation / mode: USB
NOTE: All frequencies in kHz
=====================================================================
NAT-A: Routes between 43N and 47N
During OFF-PEAK hours, primary assignment for SOUTHERLY routes
New York, Gander, Santa Maria, Shanwick
Frequency Notes
--------- --------------------------------------
3016
5598 Very active, last confirmed 2023-04-06
8906
11396
13306
17946
21925
=====================================================================
NAT-B: Routes between 47N and 64N
Assignments to aircraft flying EASTBOUND or WESTBOUND tracks
Primary for CENTRAL routes
Gander, Iceland, Shanwick
Frequency Notes
--------- --------------------------------------
2899
5616 Very active, last confirmed 2023-04-06
8864
13291
=====================================================================
NAT-C: Routes between 47N and 64N
Assignments to aircraft flying EASTBOUND or WESTBOUND tracks
Primary for CENTRAL routes
Gander, Iceland, Shanwick
Frequency Notes
--------- ---------------------------------
2872
5649 Active, last confirmed 2023-04-06
8879
11336
=====================================================================
NAT-D: Routes north of 62N
During OFF-PEAK hours, primary assignment for NORTHERLY routes
Bodo, Gander, Iceland, Shanwick, Arctic
Frequency Notes
--------- --------------------------------------
2971
4675
8891 Very active, lsat confirmed 2023-04-06
13291
=====================================================================
NAT-E: Routes between New York and Santa Maria, south of 43N
Unguarded in OFF-PEAK hours
New York, Santa Maria
Frequency Notes
--------- --------------------------------------
2962
6628 Very active, last confirmed 2023-04-06
8825
11309
13354
17952
21964
=====================================================================
NAT-F: Routes within Gander and Shanwick areas only
Gander, Shanwick
Frequency Notes
--------- -----
3476
6622
8831
13291
=====================================================================
NAT-H: Routes assigned to aircraft flying entirely within Santa Maria
area
Santa Maria
Frequency Notes
--------- -----
3491
6667
10021
=====================================================================
NAT-I
Shanwick
Frequency Notes
--------- -----
2890
6595
=====================================================================
NAT-J
Shanwick
Frequency Notes
--------- -----
3446
6547
=====================================================================
Regional and Domestic Air Route Area (RDARA)
Routes over land with no VHF coverage
Region 1/1E: 3491 5583 6667 10021 10036
Region 1B: 2890 5484 5568 6550 6595
Region 1D: 2989 5637
Region 10E: 2944 3446 4651 5460 5481 5559 5577 6547
=====================================================================
SELCAL
------
What are these weird tones you're hearing on these frequencies? These are "SELCAL"
or "selective calling" tones. These tones encode 4-letter codes that can be used
to more-or-less uniquely address one particular aircraft listening on one particular
frequency and either activate a notification light or notification chime in the
addressed aircraft when received to let the pilots know that a ground station wishes
to communicate with them. This is in order to relieve the pilots from having to
constantly monitor the voice traffic on these channels, listening for their
aircraft's callsign.
VOLMET: Weather information for aircraft in-flight
--------------------------------------------------
3413 5540 (?) 5505 8957 13264
Search and Rescue
-----------------
2182 3023 5680
See also
--------
https://wiki.radioreference.com/index.php/MWARA
https://www.iaa.ie/air-traffic-management/north-atlantic-communications/frequencies
https://www.skybrary.aero/articles/selective-calling-system-selcal
https://www.icao.int/EURNAT/EUR%20and%20NAT%20Documents/NAT%20Documents/NAT%20Documents/NAT%20Doc%20003/NAT%20Doc003%20-%20HF%20Guidance%20v3.0.0_2015.pdf
CREATED 2023-04-06
