GEN 3.4  Communication services

1  Responsible service

The Somali Civil Aviation Authority (SCAA) is the responsible entity for the provision of Telecommunication and Navigation Facility services in Somalia.

Post:

Somali Civil Aviation Authority
Mogadishu
Somalia

Tel:+2521857394

Email: mnof@scaa.gov.so

Email: ais@scaa.gov.so

AFS:HCMMYFYX
SITA:NBOTCYA

Tel:+2521857396

Email:

AFS:HCMMYFYX
SITA:NBOTCYA

The service is provided in accordance with the provisions contained in the following ICAO documents:
  • Annex 10 — Aeronautical Telecommunications
  • Doc 8400 — Procedures for Air Navigation Services — ICAO Abbreviations and Codes (PANS-ABC)
  • Doc 8585 — Designators for Aircraft Operating Agencies, Aeronautical Authorities and Services
  • Doc 7030 — Regional Supplementary Procedures
  • Doc 7910 — Location Indicators

2  Area of responsibility

Communication services are provided for the entire Mogadishu FIR. Arrangements for such services on a continuing basis should be made with the Head of Communication Services, who is also responsible for the application of the regulations concerning the design, type and installations of aircraft radio stations. Responsibility for the day-to-day operation of these services is vested in Station Communication Officers located at each international aerodrome. Inquiries, suggestions, or complaints regarding any telecommunication service should be referred to the relevant Station Communication Officer or to the Director of Communication Services, as appropriate.

3  Types of service

3.1  Radio navigation services

NIL

3.2  Voice/Data link Services
  Voice Service
The aeronautical stations maintain a continuous watch on their stated frequencies during the published hours of service unless otherwise notified.
An aircraft should normally communicate with the air-ground control radio station that exercises control in the area in which the aircraft is flying. Aircraft should maintain a continuous watch on the appropriate frequency of the ATS station and should not abandon watch, except in an emergency, without informing the control radio station.
  Data Link Service
The messages to be transmitted over the Aeronautical Fixed Service (AFS) are accepted only if:
  1. they satisfy the requirements of ICAO Annex 10, Vol. II, Chapter 3, 3.3;
  2. they are prepared in the form specified in ICAO Annex 10;
3.3  Broadcasting service

NIL

4  Requirements and conditions

The requirements of communication, Navigation and Surveillance and the general conditions under which the communication services are available for international use, as well as the requirements for the carriage of radio equipment, are contained in the Air Navigation (Radio) Regulations of SOMCARs Part 13, of the state of Somalia. and as contained in GEN-1.5.

Additionally, in the case Mogadishu ACC VHF/HF communication fails and become unreliable pilots are requested to ensure appropriate mitigation measures including using ACC SATCOM Telephone Numbers for air-ground communication +25261857390, +2521857391, +2521857392, +2521857393, +252613350047, +252623350047 and/or relay via the airline operations unit or other ACFT or other ATS units as may be applicable.

5  RT procedures at Unmanned Aerodromes

All aircraft operating at, or into, aerodromes which no Air Traffic Service is provided must broadcast their position and intentions on VHF frequency 127.45 MHz before landing and takeoff.

Initial call when in-bound:
  1. All stations (name of aerodrome)...x2
  2. Callsign and type of aircraft
  3. Direction from which the aircraft is inbound
  4. EET in minutes to a position in the circuit or overhead
  5. Any other useful information
  6. Position at which the next call will be made
In the circuit, overhead or on the manoeuvring area:
  1. (a) and (b) above
  2. Present position
  3. Intentions of the Pilot in Command
  4. Position at which the next call will be made. This will normally be the next position in the circuit or on the manoeuvring area.

Note 1 : An aircraft may not move into the landing area in use without broadcasting its intention to do so and ensuring that there is no other traffic which has right-of-way over it in that area.

Note 2 : All aircraft should try to keep the landing area in use as free as possible. Habits such as doing power checks in that area should be avoided.

6  Telecommunication Channels

The Aeronautical Fixed service (AFS) is provided in AFTN/AMHS formats for the exchange of messages and /or digital data between Aeronautical stations and other specified AMHS addressees having the same or compatible communication characteristics.The AFS service is supplemented by SITA which acts as a back-up means of communication when there is system failure. The services conform to ICAO procedures as detailed in ANNEX 10 Vol II (Aeronautical Communications) and provided through VSAT (very small aperture terminal) communication. As indicated in figure 1 below the service is only connected to the rest of the world through Nairobi communication center. Other domestic connections are yet to be implemented.

The AFTN, AMHS, SITA, E-MAIL and office telephone addresses for Aeronautical communications (AEROCOM Office) are as stated below;

AFS:HCMMYFYX

AFS:AMHS:C,=XX,A=ICAO,P=HC,O=AFTN,OU1=HCMMYFYX

SITA:SITA:NBOTCYA

Email: mnof@scaa.gov.so

Email: ais@scaa.gov.so

Tel: +2521857394

Tel:Ext:1109

Figure 2. Aeronautical Fixed Telecommunication Service for Mogadishu
../graphics/eAIP/GEN-3-4-Fig-01.png

7   CPDLC AND ADS-C

7.1  General
7.1.1 . Data link services is available to FANS1/A equipped aircraft operating in the Mogadishu FIR.
7.1.2 the following CPDLC services are provided in Mogadishu FIR:
  1. Controller to Pilot uplink of traffic information.
  2. Pilot to controller downlink of position reports and traffic information requests.
  3. Free text as a supplement to pre-formatted message elements.
  4. Note: The use of free text message elements shall be restricted to non-routine and emergency situations.
  5. Alerting services and Emergencies
7.2 
7.2.1 ADS-C is used for the following services;
  1. Automatic reporting by the aircraft Flight Management System (FMS) of aircraft position and intent Information.
  2. The FMS will report the required information in accordance with parameters selected by ground system.
  3. Alerting services and Emergencies
7.3  Log on Procedure
  1. The AFN LOGON address for Mogadishu FIR is HCSM.
  2. Standard pre-formatted message elements will be used whenever possible except for Air Traffic Services provision messages. Free text messages SHOULD ONLY be used when an appropriate pre- formatted message element does not exist or to supplement the pre-formatted message element.
  3. Aircraft requesting data link services inbound to Mogadishu FIR are required to automatically/ manually LOGON onto HCSM 10 minutes prior to estimate time for entering the airspace.
  4. Data link equipped aircraft departing from aerodromes within the Mogadishu FIR and operating from FL245 and above shall LOGON to HCSM as soon as possible after departure.
7.4  CPDLC Application Use and Application Procedure
  1. Aircraft having established data link connections will maintain CPDLC as the secondary means of communication.
  2. CPDLC will be used for provision of Flight information services only and any message sent from Mogadishu FIC shall not be construed as a clearance.
  3. When using CPDLC and ADS-C, VHF or HF voice frequencies will be used as primary communication medium.
  4. To ensure correct synchronization of messages, controller/pilot dialogue opened by voice must be closed by voice and dialogue open on CPDLC must be closed by CPDLC except in emergency.
  5. Due to inherent integrity checks and a coded reference to any proceeding related messages contained within CPDLC messages, essential traffic information issued by CPDLC only the appropriate CPDLC response.
  6. To avoid potential ambiguity the use of multiple message elements should be avoided, except when message elements are depending on each other.
  7. If multiple essential traffic information requests are contained in a single down-link message and the controller cannot approve all requests, the uplink message “ UNABLE” will be sent as a response to the entire message. A separate message containing a response to those request that can be complied with, will be sent by the controlled.
  8. If any ambiguity exists as to the intent of a particular message, clarification should be sought by voice
  9. Standard pre-formatted message elements will be used whenever possible. Free text messages SHOULD ONLY be used when an appropriate pre-formatted message element does not exist or to supplement the preformatted message element.
  10. The use of free text messages shall be for provision of Flight Information Services especially during the provision of Air Traffic Services. All ATS provision messages like essential traffic information, climb and descend requests, shall be made through free text.When CPDLC connection is established, aircraft will be instructed to transfer from voice to CPDLC. The phraseology used is: “transfer to Mogadishu FIC on datalink monitor…. (Frequency).
  11. CPDLC connections will be terminated at the FIR Boundary position or as requested by the ATS Unit.
  12. The contact (unit/name) (frequency) message and the END SERVICE message will be sent as separate messages. The END SERVICE message will be sent as soon as possible after receipt of the “WILCO” response message to a contact message.
  13. Pilots shall ensure that all uplink messages have been responded to before termination or transfer of CPDLC to another data authority.
  14. When CPDLC fails and communication reverts to voice, all CPDLC messages outstanding should be considered not delivered and effort made to re-commence dialogue by voice (VHF or HF).
7.5  ADS-C Applications
  1. When a Controller or a Pilot recognizes a failure of a CPDLC connection, they shall immediately establish voice communication on the appropriate frequency. Voice communication shall continue to be used as a primary means until a CPDLC connection has been re-established and the controller has authorized the return to data link.
  2. In the event of CPDLC failure, the controller shall immediately advice all data link connected aircraft of the failure by voice. Instructions will continue to be issued by voice until the return of data link system. The return of the system to an operational state will require a new AFN LOGON from the affected aircraft.
  3. Planned shutdown of CPDLC ground system shall be notified by publishing a NOTAM stating the shutdown period and details of voice communication frequencies to be used.
  4. In case of ADS-C failure, the controller shall inform pilots of the failure and CPDLC position reports will be used.
7.6  Emergency Procedures
  1. Pilots should notify ATC of emergency situations by the most appropriate means (voice or CPDLC).
  2. If a CPDLC MAYDAY /PAN message is received, the controller will immediately acknowledge receipt of the emergency by using the free text message “ROGER MAYDAY/PAN”.
  3. Normal emergency procedures shall be followed. Controller may also attempt to make voice contact with the pilot.
  4. For ADS-C aircraft, the ATS unit should base the provision of the alerting service on any missed scheduled report.
  5. To indicate that it is in a state of emergency or to transmit other urgent information, an aircraft equipped with ADS-C might operate the emergency and/or urgency mode as follows:
    1. Emergency;
    2. Communication failure;
    3. Unlawful interference;
    4. Minimum fuel and; and/or Medical.
7.7  When an ADS-C emergency and/or urgency report is received, the controller with responsibility for the flight must acknowledge receipt of the information by the most appropriate means of communication.
7.8  Flight plan notification
Aircraft planning to utilize data link communication must annotate their ICAO flight plan as follows:
  1. CPDLC Capability must be notified by inserting the alphanumeric designator J4 in item 10 field 10a;
  2. ADS-C capability must be notified by inserting the alphanumeric designator D1 in item 10 field 10b;
  3. Aircraft registration must be inserted in item 18 as the ground system uses the information during the AFN LOGON

8  Miscellaneous

Figure 3. Aeronautical Fixed Service-NAVISAT, VSAT
Figure 4.  Aeronautical Fixed Service-NAVISAT Direct Speech Circuits and Telephones
Figure 5.  HF Communication