It turns out to be the personal aircraft of the president of Turkmenistan. A bit of an illusive aircraft because not many details are known. However a fellow PP pointed me in the direction of an interesting article:
A rare image of the actual airplane can be found here.
The aircraft apparently landed at KADM this same day after a stop over at probably KPQI. The reason for the aircraft being at the destination is probably for maintenance or upgrades / alterations to systems or the interior.
Today I received two HFDL messages from Reykjavik to, apparently, a KC-135:
[2022-04-06 16:08:05 GMT] [17985.0 kHz] [-5.4 Hz] [-42.3/-52.7 dBFS] [10.4 dB] [300 bps] [S] Uplink LPDU: Src GS: Reykjavik, Iceland Dst AC: 255 Type: Logon confirm ICAO: AE07C0 AC info: 63-8006, Boeing, KC-135R, United States Air Force Assigned AC ID: 33
[2022-04-06 16:10:13 GMT] [17985.0 kHz] [-5.9 Hz] [-44.5/-53.5 dBFS] [9.0 dB] [300 bps] [D] Uplink LPDU: Src GS: Reykjavik, Iceland Dst AC: 255 Type: Logon confirm ICAO: AE07C0 AC info: 63-8006, Boeing, KC-135R, United States Air Force Assigned AC ID: 33
When checking the HEX on adsbexchange the aircraft was active as SABRE36 overhead Texas. A bit odd… but the HFDL data seems to be correct, and it was also received twice. So, my first KC-135 on HFDL I think…
And also so more remarkable data:
[2022-04-06 07:11:45.527 GMT] [8977.0 kHz] [2.4 Hz] [-32.1/-40.2 dBFS] [8.1 dB] [300 bps] [S] Downlink LPDU: Src AC: 255 Dst GS: Reykjavik, Iceland Type: Logon resume ICAO: 3F9A92 AC info: 15+03, Airbus, ACJ319 133X, German Air Force Frequency data: Flight ID: OSY11D Lat: 44.5561687 Lon: 26.1533473 Time: 07:11:40 GS ID: Reykjavik, Iceland Listening on: 17985.0, 8977.0, 6712.0, 5720.0, 3900.0 Heard on: 8977.0 GS ID: Molokai, Hawaii Listening on: 21937.0, 13324.0, 11348.0, 11312.0, 10027.0, 8936.0, 8912.0 Heard on: GS ID: Agana, Guam Listening on: 21928.0, 17919.0, 13312.0, 11306.0, 8927.0, 6652.0, 5451.0 Heard on: GS ID: Riverhead, New York Listening on: 21931.0, 17919.0, 13276.0, 11387.0, 8912.0, 6661.0, 5652.0 Heard on: GS ID: Al Muharraq, Bahrain Listening on: 21982.0, 17967.0, 13354.0, 10075.0, 8885.0, 5544.0 Heard on: GS ID: Hat Yai, Thailand Listening on: 13270.0, 8825.0, 6535.0, 5655.0 Heard on:
OSY used to be the Open Skies callsign / flight ID. And indeed 15+03 was the German Open Skies aircraft. But I don’t think there are still Open Skies missions. And then this data also appeared: