The Global HF System (GHFS) was stated by the US Air
Force in June of 1992. This system was created by consolidating several
other USAF HF networks, including the Strategic Air Command "Giant Talk"
system. The goal of the system was to develope a worldwide HF network for
providing Command & Control HF communictions to all authorized DOD aircraft
and ground stations.
When you hear an aircraft or any stations calling "MAINSAIL" on any of the
GHFS frequencies this is a "general" call for any ground station to answer
and provided the calling stations with what ever he needs. Any GHFS ground
station will respond to the call "MAINSAIL". Depending on the service required,
the station bay request the aircraft to change to a discrete frequency for
improved and extended service.
EAM's or Emergency Action Message. Another very
important aspect of the GHFS is the transmission of EAM's. EAM's are the
coded military orders or bulletins that have the highest priority. When
EAM's are broadcast, ALL other users of the system are to standby. If you
hear a voice giving a long series of letters phonically this is an EAM.
SKYKING messages are special EAM's. These presumably could be the
nuclear go/no-go codes. There was a higher than normal number of EAM's and
SKYKING messages being transmitted after the attackes of 9/11/01. Urgent
SKYKING messages are repeated three or four times instead of the usual two.
SKYKING is a group callsign, meaning "Any
| Frequency KHz-USB | Description |
| 4709 | Sigonella |
| 4724 | Andrews, Ascension, Elmendorf, Guam, Hickam, Lejes, Offutt, Salinas, Thule, Yokota |
| 6712 | Andrews, Ascension, Guam, Lajes |
| 6724 | Sigonella |
| 6739 | Ascension, Elmendorf, Guam, Hickam, Salinas, Offutt, Thule, Yokota |
| 8992 | Andrews, Ascension, Elmendorf, Guam, Hickam, Offutt, Salinas, Thule, Yokota |
| 9007 | Sigonella |
| 9025 | Lejes |
| 10780 (1) | AF Eastern Test Range (Backup for Ascension), Cape Canaveral, Antigua, Ascension, Maui |
| 11175 (2) | Andrews, Ascension, Elmendorf, Guam, Hickam, Salinas, Offutt, Thule, Yokota |
| 11181 | Lajes |
| 11271 | Andrews, Ascension, Elmendorf, Guam, Hickam, Lejes, Offutt, Salinas, Thule, Yokota |
| 13212 | Lajes |
| 15016 | Andrews, Ascension, Elmendorf, Guam, Hickam, Lajes, Offutt, Salinas, Thule, Yokota |
| 15038 | Sigonella |
| 20390 | AF Eastern Test Range (Backup for Ascension), Cape Canaveral, Antigua, Ascension, Maui |
