USAF High Frequency Global Communications System

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
        GHFS now HF-GCS - most frequencies and times unchanged
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

                       HF-GCS History

HF-GCS used to be GHFS.

GHFS began on 1 June 1992, when it was created out of two earlier HF
networks, the GIANT TALK used by the Strategic Air Command, and the
Global Command and Control System (GCCS), used by the rest of the
Air Force.  This consolidation reflected the reorganization of the
Air Force following the end of the cold war, with SAC becoming part
of United States Strategic Command (STRATCOM), TAC becoming the Air
Combat Command (ACC), and MAC becoming the Air Mobility Command
(AMC aka "Reach").

GHFS became HFGCS in 2003, on completion of the multiyear equipment
upgrade called SCOPE COMMAND, and control finally moved to Andrews.
However, the ground stations are extremely configurable and can be
operated locally, remotely, or both.

Full documentation of HF-GCS is in the unclassified US mlitary Flight
Information Handbook, published twice a year.

USAF HF-GCS STATION LIST

Andersen Air Base             Guam
Andrews Air Force Base        MD
Ascension Island AF           S Atlantic
Croughton AB                  UK
Diego Garcia NS               Indian Ocean
Elmendorf AFB                 AK
Hickam AFB                    HI
Keflavik NAS                  Iceland
Lajes AB                      Azores
McClellan AB                  CA
Offutt AFB                    NE
Sigonella NAS                 Sicily
Salinas                       PR
Yokota AB                     Japan

HF-GCS FREQUENCY SCHEDULE

Summer	=	April-September
Winter	=	October-March

Andersen Air Base (AB), Guam (Voice call: Guam)
	Summer:	4724 (1300-2000) 
			6739 (1100-2000) 
			8992 (24h)
			11175 (24h)
			13200 (2000-1300)
			15016 (2000-1100)
	Winter:	4724 (1200-2030) 
			6739 (1000-2030) 
			8992 (24h)
			11175 (24h)
			13200 (2030-1200)
			15016 (2030-1000)
	ALE Address:	GUA 
	ALE Frequencies:	3137 4721 5708 6721 9025 11226
				13215 15043 18003 23337

Andrews AFB, Maryland (Voice call: Andrews)
HF-GCS CNCS (Centralized Net Control Station)
	Winter:	4724 (0200-1230) 
			6712 (2400-1230) 
			8992 (24h)
			11175 (24h)
			13200 (1230-0200)
			15016 (1230-2400)
	Summer:	4724 (0430-0930) 
			6712 (0230-0930) 
			8992 (24h)
			11175 (24h)
			13200 (0930-0230)
			15016 (0930-0230)
	Discrete:	8058 11053 11159 11181 11220 11460
	ALE Address:	ADW
	ALE Frequencies	3137 4721 5708 6721 9025 11226
				13215 15043 18003 23337

Ascension Island (Voice call: Ascension)
	Year round:	4724 (2400-0700) 
			6739 (1900-2400) 
			8992 (24 Hrs)
			11175 (24 Hrs) 
			15016 (0700-1900)
	Discrete:	11159 11226 14497
	ALE Address:	HAW
	ALE Frequencies:	3137 4721 6721 9025 11226
				13215 15043 18003 23337

Croughton AB, United Kingdom (Voice call: Croughton)
	Winter:	4724 (1800-0800) 
			6712 (1800-0800) 
			8992 (24h)
			11175 (24h)
			13200 (0800-1800)
			15016 (0800-1800)
	Summer:	4724 (2230-0400) 
			6712 (2230-0400) 
			8992 (24h)
			11175 (24h)
			13200 (0400-2230)
			15016 (0400-2230)
	Discrete:	4894 5708 5117 6728 6731 6993 7567
			7933 8032 10648 11118 11129 11181 11226 
			11232 11271 13822 15091
	ALE Address:	CRO 
	ALE Frequencies:	3137 4721 6721 9025 11226
				13215 15043 18003 23337

Diego Garcia Naval Station, Indian Ocean (Voice call: Diego Garcia)
	Year round:	8992 (24h)
			11175 (24h)
	Discrete:	9012 11181 11226 11244 11269 13254
			15095 20910
	ALE Address: JDG 
	ALE Frequencies:	3137 4721 5708 6721 9025 11226
				13215 15043 18003 23337

Elmendorf AFB, Alaska (Voice call: Elmendorf)
	Winter:	4724 (0230-1900) 
			6739 (0030-2130) 
			8992 (24h)
			11175 (24h)
			13200 (1900-0230)
			15016 (2130-0030)
	Summer:	4724 (1000-1300) 
			6739 (0800-1400) 
			8992 (24h)
			11175 (24h)
			13200 (1300-1000)
			15016 (1400-0800)
	ALE Address:	AED
	ALE Frequencies:	3137 4721 5708 6721 9025 11226
				13215 15043 18003 23337

Hickam AFB, Hawaii (Voice call: Hickam)
	Summer:	4724 (1000-1600) 
			6739 (0500-1000) 
			8992 (24h)
			11175 (24h)
			13200 (2000-1300)
			15016 (2000-1100)
	Winter:	4724 (0800-1700) 
			6739 (0400-0800) 
			8992 (24h)
			11175 (24h)
			15016 (1700-0400)
	Discrete:	11181 13242
	ALE Address:	HIK
	ALE Frequencies:	3137 4721 6721 9025 11226 13215
				15043 18003 23337

Keflavik NAS, Iceland
(Replaces Thule AB, Greenland)
	Year round/24 hours: 8992 11175 13200 15016
	ALE address:	IKF.

Lajes AB, Azores (Voice call: Lajes)
	Summer:	4724 (2230-0400) 
			8992 (24h)
			11175 (24h)
			13200 (24h)
			15016 (0400-2230)
	Winter:	4724 (1800-0800) 
			8992 (24h)
			11175 (24h)
			13200 (24h)
			15016 (0800-1800)
	Discrete:	11220 13440 14896
	ALE Address:	PLA
	ALE Frequencies:	3137 4721 5708 6721 9025 11226
				13215 15043 18003 23337

McClellan, California (Voice call: McClellan)
	Summer:	4724 (0730-1300) 
			6739 (0530-1300) 
			8992 (24h)
			11175 (24h)
			13200 (1300-0730)
			15016 (1300-0530)
	Winter:	4724 (0500-1530) 
			6739 (0300-1530) 
			8992 (24h)
			11175 (24h)
			13200 (1530-0500)
			15016 (1530-0300)
	ALE Address:	MCC
	ALE Frequencies:	3137 4721 5708 6721 9025 11226
				13215 15043 18003 23337

Offutt AFB, Nebraska (Voice call: Offutt)
Alternate control point
	Summer:	4724 (0600-1100) 
			6739 (0400-1100) 
			8992 (24h)
			11175 (24h)
			13200 (1100-0600)
			15016 (1100-0400)
	Winter:	4724 (0300-1400) 
			6739 (0100-1400) 
			8992 (24h)
			11175 (24h)
			13200 (1400-0300)
			15016 (1400-0100)
	Discrete:	11181
	ALE Address:	OFF
	ALE Frequencies:	3137 4721 5708 6721 9025 11226
				13215 15043 18003 23337

Salinas, Puerto Rico (Voice call: Puerto Rico)
	Summer:	4724 (0300-1000) 
			6739 (0100-1000) 
			8992 (24h)
			11175 (24h)
			13200 (1000-0300)
			15016 (1000-0100)
	Winter:	4724 (0200-1100) 
			6739 (2400-1100) 
			8992 (24h)
			11175 (24h)
			13200 (1100-0200)
			15016 (1100-2400)
	Discrete:	9006 10648 11056 11220 11484 15087
	ALE Address:	JNR
	ALE Frequencies:	3137 4721 5708 6721 9025 11226
				13215 15043 18003 23337

Sigonella Naval Station, Sicily, Italy (Voice call: Sigonella)
	Summer:	4724 (2230-0400) 
			6739 (24h) 
			8992 (24h)
			11175 (24h)
			13200 (24h
			15016 (0400-2230)
	Winter:	4724 (1800-0800) 
			6739 (24h) 
			8992 (24h)
			11175 (24h)
			13200 (24h
			15016 (0800-1800)
	ALE Address:	ICZ
	ALE Frequencies:	3137 4721 5708 6721 9025 11226
				13215 15043 18003 23337

Yokota AB, Japan (Voice call: Yokota)
	Summer:	4724 (1200-1930) 
			6739 (1000-2130) 
			8992 (24h)
			11175 (24h)
		13200 (1930-1200)
		15016 (2130-1000)
	Winter:	4724 (0930-2200) 
			8992 (24h)
			11175 (24h)
			6739 (0730-2400) 
			13200 (2200-0930)
			15016 (2400-0730)
	ALE Address:	JTY
	ALE Frequencies	3137 4721 6721 9025 11226 13215
				15043 18003

Air Force Eastern Test Range, Florida
(Voice call: Cape Radio)
Backup to HF-GCS
			10780 (primary)
			20390 (secondary)
	ALE:		None

"MPA"
Location unknown- Falklands or ????
	ALE Address:	MPA
	ALE Frequencies	3137 4721 6721 5708 9025 11226 13215
				15043 18003 23337
	No voice heard

Other HFGCS Facts

EAM stands for Emergency Action Message. These coded military
orders or bulletins have higher traffic priority than all other
traffic except in-flight emergencies.  Other users of the 
frequencies are supposed to stand by when one is in progress.
(In practice, they often don't.)

The distinctive touch-tone beeps (DTMF tones) heard at the end of
transmissions from Offutt and some others are left over from Giant
Talk, and may eventually be replaced by another system.  Offutt,
in particular, has capability to seize most or all of the ground
net, and truly talk like a giant.  The beeps key and unkey remote
transmitters.  The echoes heard are both propagation delays and
the result of slow landlines or satellites going to the distant
sites.

SKYKING messages are special EAM, Emergency Action Messages,
presumably the nuclear go/no-go codes.  Urgent ones are repeated
three or four times, instead of the usual two.  SKYKING is a group
callsign for units in the Single Integrated Operation Plan for
strategic operations."  "Do not answer" is the standard procedure
for self-authenticating broadcasts, meaning that recipients don't 
need to give away their positions or existence by challenging the
traffic.

From the start, HFGCS was intended for multi-service use.  It replaced
US Navy's Fleet HICOM (High Command), which phased out and is now
dead, though frequencies are occasionally used for other purposes.
One also hears US Army vessels (yes, the Army has a "navy").

Finally, this leaves 6761, the former SAC night primary, as an
air-to-air channel.  Though it's not technically part of HFGCS, it is
often busy during training exercises, as planes schedule boom time.

HFGCS Lexicon:

A---            US Army callsign, usually a troop boat or terminal
AR              Aerial Refueling, usually with a track number
AUTODIN         Automated Digital Network
Block time      Final arrival time, when plane is in the blocks
Class A, B      Refers to explosive on board
DSN             Defense Switched Network, old "Autovon"
DV              Distinguished Visitor
FL              Flight level (altitude when higher up)
Hazmat          Hazardous cargo
IFE             Inflight emergency, as declared by pilot
IR              Instrument Route; aerial training routes
MAINSAIL        General call: Any ground station this net
METRO           Base weather office
NIPRNET         Non-Secret Internet Protocol Routing Network  
Offload         Fuel, in pounds
Pallets         Cargo
Pax             Passengers
PIREP           Pilot Report; weather observation with standard items
REACH           Standing callsign: any AMC flight.  Followed by
                tail or mission number, sometimes a letter in large
                ops.
RON             Remain Over Night (crew needs place to sleep)
RTB             Return To Base, mission aborted
SAM             Special Air Mission (VIP)
SIPRNET         Secure Internet Protocol Routing Network  
SKYBIRD         Group callsign: all STRATCOM assets on net
SKYKING         Group callsign: all SIOP assets on net

                                     --end-