From the DOD Flight Information Handbook October 2002 USAF HIGH FREQUENCY GLOBAL COMMUNICATIONS SYSTEM (HF-GCS) MODERNIZATION - SCOPE Command replaces older high power Global HF equipment. SCOPE Command incorporates Automatic Link Establishment (ALE) to automate/ enhance communications. By Jan 03, all HF-GCS station transmit and receive equipment will be remotely controlled from the Centralized Net Control Station (CNCS) at Andrews AFB MD. PROCEDURES - General Calling. Aircrews use a preliminary call as outlined in ACP-121 US Supp 2 using the collective callsign "MAINSAIL" or the HF-GCS station call sign (example: Sigonella Global this is Dark 86 on 11175, OVER). HF-GCS operators require approximately 10 seconds (for automated equipment configuration) to respond to calls for service. The HF-GCS operator may request the aircraft change to a discrete frequency for improved and/or extended service. Phone Patch Service. Phone patching allows direct voice communications between ground agencies and aircraft by electronically connecting telephone circuits to radio transmitters and receivers. Phone patch service is reserved for official unclassified business only and shouldn’t exceed 5 minutes. Patches of more than 5 minutes or of a sensitive nature should be run on a discrete frequency. Aircrews requesting a phone patch must include all information necessary for HF-GCS operators to complete the call, such as the identity or location of the called parties and telephone number if known. Phone patches are monitored by HF-GCS operators and if radio reception isn’t of sufficient quality to complete the patch, they will attempt to copy the traffic and relay it to addressees. Message Relay Service. HF-GCS operators transcribe encoded or plain-text messages for aircraft or ground stations and forward them to the addresses by radio or landline. The text of the messages can be in the form of alphanumerics, code words, plain text, acronyms, and/or numerical sequences. Aircrews may use "READ BACK" procedures when the message data is critical, or when an incomplete transmission is suspected due to poor radio reception. All messages received by Global stations will be accepted and delivered by the fastest means available according to precedence and priority. ALE - ALE allows automated ground agency contact by selecting the best station and best frequency without operator interaction. ALE radios make this possible by using a datafill that contains frequency, station and other pertinent information. For ALE radios to operate properly, the radio must have a loaded datafill, be turned on in the “automatic” mode and remain there the duration of the flight. If the radio is removed from the ALE mode, history tables will require time to rebuild and initial communications may be slightly degraded. HF Data Service. All HF-GCS stations have HF data access to AUTODIN and SACCS. HF Radio Teletype requirement has been removed by Joint Staff J6. Command and Control Mission Following. C2 agencies can use the HF-GCS for mission tracking/control of their aircraft. Aircraft responsible to a C2 agency for mission tracking/ control should transmit an initial contact/departure report to a Global HF System station after takeoff. The following information should be included: - Aircraft Call Sign - Departure point and time - Destination point and ETA EMERGENCY ACTION MESSAGE (EAM) BROADCASTS - Most HF-GCS stations transmit high priority EAMs on published frequencies during specific broadcast periods. During EAM broadcast periods, aircraft may only transmit In-Flight Emergency traffic. HF DIRECTION FINDING (D/F) ASSISTANCE - HF-GCS stations are capable of coordinating D/F efforts between aircraft and direction finding facilities for both emergency situations and suspected spectrum interference location efforts. Emergency D/F Requests. Aircraft requiring D/F support should advise the HFGCS station of the nature of the emergency, a bearing (steer) or a position (fix). The HF-GCS operator will arrange the support and ask the aircraft to transmit a slow count from 1 to 10 and back, followed by the aircraft call sign. The aircraft should then standby for further instructions and/or results of the service. D/F facility response time will vary, depending on operating conditions, location of the aircraft, nature of request, prevailing DF facility operating commitments, type of D/F facility providing the service and coordination of all concerned. The average response time is estimated at four minutes for bearings and ten minutes for positions after the slow count. DF Support for Suspected Spectrum Interference. Aircraft experiencing spectrum interference may obtain D/F fix information on source of interference by calling the nearest HFGCS station and requesting Spectrum Interference D/F support. The aircraft will advise the Global stations of the frequency affected, type of interference (Voice, Morse Code, Printer, Noise, etc.) and request a read-back of the information passed. A report will be filed in accordance with AFI 10-707 by the aircrew upon landing. The Andrews CNCS will report Spectrum Interference D/F results via message to the AF Frequency Management Agency and the aircraft unit command post. ATC SUPPORT - HF-GCS is not configured to meet ATC communications routing requirements and cannot provide ATC flight following service. This service can be obtained through the appropriate Civil/ICAO ATC communications agency such as the AREA CONTROL CENTER, SECTOR RADIO, or FLIGHT INFORMATION CENTER (see section B, ICAO HF Aeronautical Station List). Global HF stations will accept emergency ATC traffic and provide phone patch or message relay support as required. AMC OPERATIONS CENTER - The USAF Air Mobility Command (AMC) Tanker Airlift Control Center (TACC) provides worldwide C2 for AMC missions, while the appropriate theater Air Mobility Control Center (AMCC) provides C2 for theater operated missions. Either the TACC or appropriate AMCC can be contacted for airlift movement reporting and/or assistance directly through the Global stations. The voice call sign "MAINSAIL" may be used for establishing initial contact. Following initial contact, aircrews may request a phone patch to the desired center as follows: Elmendorf AFB Air Mobility Control Center-DENALI 317-552-3258 317-552-2858 Osan Air Mobility Control Center-BRICKWALL 315-784-6500 315-784-4893 Scott AFB Tanker Airlift Control Center-HILDA GLOBAL 312-779-0348 USAF Europe Tanker Recce Airlift Control Center-TRACKER 314-480-9292 314-480-9293/9294