Aeronautical radio service on Short Waves
When aircrafts fly across uninhabited regions like oceans or deserts, no contact to ground stations is possible with the VHF radio. They have to switch to shortwave or satellite communication.
This is the case for an Atlantic crossing. The following frequencies get used:
North Atlantic Route A: 5598 kHz - 8906 kHz - 13306 kHz
North Atlantic Route B: 5616 kHz - 8864 kHz - 13291 kHz - 17946 kHz
North Atlantic Route C: 5649 kHz - 8879 kHz - 11336 kHz - 13306 kHz
North Atlantic Route D: 4675 kHz - 8891 kHz - 11279 kHz - 13291 kHz
North Atlantic Route E: 6628 kHz - 8825 kHz - 11309 kHz - 13354 kHz - 17952 kHz
North Atlantic Route F: 6622 kHz - 8831 kHz - 13291 kHz
Stockholm Radio: 8930 kHz - 11345 kHz - 13342 kHz - 17916 kHz - 23210 kHz
Tripoli Radio (African Airtraffic): 11300 kHz
>>> Browse through the indicated frequencies.