The responsible service for the provision of communication and navigation facility services in the Republic of Latvia is the State Joint-Stock Company "Latvijas gaisa satiksme".

Post:

State Joint-Stock Company

“Latvijas gaisa satiksme”

Muzeju iela 3, Lidosta “Rīga”

Mārupes pagasts, Mārupes novads, LV-1053

Latvija

Tel: +371 67300950

Fax: +371 67300970

Email: lgs@lgs.lv

AFS: NIL

URL: https://www.lgs.lv

The services are 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;

• Doc 9869 - Performance-based Communication and Surveillance (PBCS) Manual;

• Doc 9880 - Technical Specification for ATN using ISO/OSI Standards and Protocols - Part II - Ground-Ground Applications - Air Traffic Services Message Handling Services (ATSMHS).

Differences to ICAO Annex 10 provisions are detailed in subsection GEN 1.7.

Communication services are provided for the entire Riga FIR.

Arrangements for such services on a continuing basis should be made with the Board of the State Joint-Stock Company "Latvijas gaisa satiksme".

Enquires, suggestions or complaints regarding any communication service should be referred to the State Joint-Stock Company "Latvijas gaisa satiksme" or the State Agency “Civil Aviation Agency”, as appropriate.

Post:

Civil Aviation Agency

Lidosta “Rīga”, Biroju iela 10

Mārupes pagasts, Mārupes novads

LV-1053

Latvija

Tel: +371 67830936

Fax: +371 67830967

Email: caa@caa.gov.lv

URL: https://www.caa.gov.lv

1. Radio Navigation Services

The following types of radio navigation services and aids are available:

• Global Navigation Satellite System (GNSS)

GPS L1 (See ENR 4.3)

EGNOS L1 (See ENR 4.3)

• Instrument landing system (ILS)

ILS18 CATII/D/3 - Riga (See AD 2 EVRA AD 2.19)

ILS36 CATII/D/3 - Riga (See AD 2 EVRA AD 2.19)

ILS24 CATI/T/2 - Liepaja (See AD 2 EVLA AD 2.19)

ILS18 CATI/T/2 - Lielvarde (See AD 2 EVGA AD 2.19)

• VHF omnidirectional radio range (VOR)

DVOR RIA - Riga (See AD 2 EVRA AD 2.19 and ENR 4.1)

DVOR LEP - Liepaja (See AD 2 EVLA AD 2.19 and ENR 4.1)

DVOR DGP - Daugavpils (See ENR 4.1)

VOR TUK - Smarde (See AD 2 EVRA AD 2.19 and ENR 4.1)

VOR VEN - Ventspils (See ENR 4.1)

VOR LBN - Trakshi (See ENR 4.1)

• Distance measuring equipment (DME)

DME RIA - Riga (See AD 2 EVRA AD 2.19 and ENR 4.1)

DME LEP - Liepaja (See AD 2 EVLA AD 2.19 and ENR 4.1)

DME TUK - Smarde (See AD 2 EVRA AD 2.19 and ENR 4.1)

DME VEN - Ventspils (See ENR 4.1)

DME LBN - Trakshi (See ENR 4.1)

DME DGP - Daugavpils (See ENR 4.1)

DME JVL - Jaunsvirlauka (See ENR 4.1)

DME RDB - Rudbarzhi (See ENR 4.1)

DME RSK - Raiskums (See ENR 4.1).

Explanation of PBN specification

The following PBN specifications are in use in the Riga FIR:

• RNAV 5, RNAV 1, RNP 1, RNP APCH and RNP AR APCH.

En-route application is based on RNAV 5 specification in the Riga FIR. RNAV 5 is supported by VOR/DME and DME/DME beacons.

Terminal applications are based on:

- RNAV 1 in the Riga TMA. RNAV 1 is supported by DME/DME beacons and GPS L1. DME TUK and DME JVL are critical for SID RWY18 and SID RWY36 until 1000 feet;

- RNP 1 in the Liepaja FIZ Sector B. RNP 1 is supported by GPS L1.

Approach applications are based on:

At Riga AD:

- RNP APCH (LNAV, LNAV/VNAV) RWY 18/36 and RNP AR APCH RWY 18/36, all supported by GPS L1;

- RNP APCH (LPV) RWY 18/36 supported by GPS L1 and EGNOS L1.

At Liepaja AD:

- RNP APCH (LNAV, LNAV/VNAV) RWY 06/24 supported by GPS L1;

- RNP APCH (LPV) RWY 06/24 supported by GPS L1 and EGNOS L1.

At Lielvarde AD:

- RNP APCH (LNAV, LNAV/VNAV) RWY 18/36 supported by GPS L1;

- RNP APCH (LPV) RWY 18/36 supported by GPS L1 and EGNOS L1.

Explanation of ILS classification

According to the specifications in ICAO Annex 10, Volume 1, Attachment C, section 2.14.

The ILS localizer is characterised by a classification code which has 3 alphanumeric characters:

• conformance to Facility Performance Category. This character can be specified by:

I: Facility Performance Category I

II: Facility Performance Category II

The facility performance category corresponding to this digit is described in detail in ICAO Annex 10, Volume I (Chapter 3, 3.1.3).

• Quality of course structure. This character consists of one of the following letters:

A, B, C, T, D or E. It indicates the ILS point up to which the course structure meets the requirements given in ICAO Annex 10, Volume I, Chapter 3, 3.1.3.4.2, except the letter T designating the runway threshold. These points are defined in Chapter 3, 3.1.1; see also the illustration in ICAO Annex 10, Volume I, Attachment C, Fig. C-1.

• Level of reliability (Integrity and continuity of service)

One of the following levels is used for designation: 1, 2, 3 or 4. It describes both the level of continuity of service and integrity of the localizer in accordance with ICAO Annex 10, Volume I (Chapter 3, 3.1.3.12 and summarized in Attachment C, Table C-4).

The ILS glide path is characterised by a classification code which has 3 alphanumeric characters:

• conformance to Facility Performance Category. This character can be specified by:

I: Facility Performance Category I

II: Facility Performance Category II

The facility performance category corresponding to this digit is described in detail in ICAO Annex 10, Volume I (Chapter 3, 3.1.3 and 3.1.5).

• Quality of glide path structure. This character consists of one of the following letters:

A, B, C or T. It indicates the ILS point up to which the glide path structure meets the requirements given in ICAO Annex 10, Volume I, Chapter 3, 3.1.5.4.2, except the letter T designating the runway threshold. These points are defined in Chapter 3, 3.1.1; see also the illustration in ICAO Annex 10, Volume I, Attachment C, Fig. C-1.

• Level of reliability (Integrity and continuity of service)

One of the following levels is used for designation: 1, 2, 3 or 4. It describes both the level of continuity of service and integrity of the glide path in accordance with ICAO Annex 10, Volume I (Chapter 3, 3.1.5.8 and summarized in Attachment C, Table C-4).

Examples:

Localizer classification II/D/3 means:

• the localizer meets all ICAO requirements for localizer Facility Performance Category II,
• the course structure meets the requirements for the course structure of facility performance Category III up to the ILS point D,
• the level of reliability is 3.

Glide path classification II/T/3 means:

• the glide path meets all ICAO requirements for glide path Facility Performance Category II,
• the glide path structure meets the requirements for the glide path structure of facility performance Category III up to the ILS point T,
• the level of reliability is 3.

Localizer classification I/T/2 means:

• the localizer meets all ICAO requirements for ILS Facility Performance Category I,
• the course structure (furthermore) meets the requirements for the course structure of facility performance category III up to the ILS point T,
• the level of reliability is 2.

Glide path classification I/T/2 means:

• the glide path meets all ICAO requirements for ILS Facility Performance Category I,
• the glide path structure (furthermore) meets the requirements for the course structure of facility performance category III up to the ILS point T,
• the level of reliability is 2.

ILS operations

The quality of ILS signal-in-space (SIS) is guaranteed by equipment performance and by protection of critical and sensitive areas (CSA) from unacceptable disturbance caused by aircrafts and/or vehicles movements. Any movements within CSA during ILS operations are controlled by the Tower.

For ILS CAT I/II approaches the pilot shall be aware that the ILS is available and CSA are controlled. If the pilot is unable to do this for any reason, he/she should anticipate the possibility of ILS signal disturbances.

The pilots should note that CAT II quality of the ILS SIS will only be guaranteed when Low Visibility Procedures (LVP) are in operation.

Failures and changes in the state of ILS facilities:

• Any failure or change in the state of ILS operations will be notified by NOTAM, ATIS or ATC.
• Operations will be suspended if the equipment does not meet ILS requirements for the corresponding category.
• Operations will be suspended if the ILS critical or sensitive areas are not guaranteed.

Low visibility operations

For details of low visibility procedures, see the local aerodrome regulations for the appropriate aerodrome (refer to AIP, AD 1.1.3 and AD 2.22).

ILS LOC guided take-off

Low visibility take-off with LOC guidance is not available (refer to AIP, AD 1.1.3 and EVRA AD 2.22).

Identification signal for unserviceable radio navigation aids

Radio navigation aids with “TST” or missing identification signals are prohibited for operational use.

2. Voice and/or data link services

Mobile service

The air navigation services 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 navigation service which exercises control in the area in which it is flying. Aircraft should maintain continuous watch on the appropriate frequency of the air navigation service and should not abandon watch, except in an emergency, without informing the control radio station.

For VFR flights within uncontrolled airspace (Class G) the 123.950 MHz radio frequency may be used as the common traffic advisory frequency (CTAF) by pilots for self –announcing their positions and intentions in the blind or for air–air communications in order to exchange information.

Fixed service

The messages to be transmitted over the Aeronautical Fixed Service (AFS) are accepted only if:

a) they satisfy the requirements of ICAO Annex 10, Vol. II, Chapter 3.3;

b) they are prepared in the form specified in ICAO Annex 10;

c) the text of an individual message does not exceed 1800 characters.

The rules and procedures for handling of communications over the AFS are contained in ICAO Annex 10, Volume II, Chapters 3 and 4.

Aeronautical Fixed Circuits – National Circuits

CIVIL AVIATION AGENCY

Agency	EVRCYAYX
Frequency coordination	EVRRYTYX

LATVIJAS GAISA SATIKSME

COM	EVRRYFYX
AIS/NOF	EVRAYNYX
TWR	EVRAZTZX
MET	EVRAYMYX
ARO	EVRAZPZX
Air Traffic Flow management Division	EVRRZQZX EVRRZDZX
AMC	EVRRZAMC
ACC	EVRRZRZX

CIVIL AIRPORTS AND AERODROMES

RIGA	EVRAYDYD
VENTSPILS	EVVAZTZX
LIEPAJA	EVLA
SPILVE	EVRSYDYD

MILITARY AUTHORITIES

MIL	EVRRYWYX EVGA

MET AUTHORITIES

MET OFFICE

EVRCYMYX

AIRLINES

AirBaltic	EVRABTIO
Baltic Jet	EVRABJCX
VIP AVIA	EVRAPRXX
SmartLynx Airlines	EVRALTCX

Data Link Services - Controller-Pilot Data Link Communications (CPDLC)

General

Provision of CPDLC in the RIGA FIR is based on the requirements of the COMISSION REGULATION (EC) No. 29/2009. CPDLC is available for all properly equipped flights operating as general air traffic in accordance with the instrument flight rules within the controlled airspace above FL 285.

The following data link services provided in this airspace:

• Data Link Communications Initiation Capability (DLIC);

• ATC Clearances and Information service (ACL);

• ATC Communications Management service (ACM);

• ATC Microphone Check service (AMC).

The use of CPDLC is not mandatory in the RIGA FIR. CPDLC is conducted at the discretion of ATC and by the initiative of the pilot concerned.

Initial contact with ATS unit is provided by voice communication.

Voice shall remain as the primary mean of communication in time-critical situations.

Flight Plan

Pilot intending to conduct CPDLC communications within the RIGA FIR shall file the flight plan as follows:

• in Item 10a - J1 for CPDLC ATN VDL Mode 2 capable aircraft;

• in Item 18 - the indicator CODE/ followed by the aircraft 24-bit address expressed in an alphanumerical code of six hexadecimal characters.

CPDLC Use

Within the RIGA FIR, CPDLC exchanges may only be conducted when the aircraft is under control of RIGA ACC.

In the area of responsibility of RIGA ACC, voice communication and radiotelephony instructions have priority over CPDLC instructions at all times.

CPDLC clearance shall not be executed by the crew until the pilot has sent a WILCO message in response to the CPDLC clearance or instruction received.

Voice read back is not required for any CPDLC instruction.

In case of any uncertainty about a data link message, voice communication shall always be used.

If the pilot or ATC is in the opinion that CPDLC should no longer be used in the given circumstances, CPDLC shall be discontinued or terminated and the other party shall be informed about this by voice communication.

Data Link Communications Initiation Capability (DLIC) – Log-on

The data link address for RIGA ACC is EVRR.

Normally log-on should be initiated 10 to 15 minutes prior to entering the RIGA FIR. Log-on shall be initiated by the pilot. The pilot shall log-on using ICAO callsign as filed in the flight plan.

Irrespective of the number of RIGA ACC sectors which are entered during the flight, only one log-on per flight is required.

ATC Clearances and Information service (ACL)

The pilot may request changes to flight levels (climb or descent) or clearance direct to a point on the route via the data link. The pilot can send emergency messages via the data link as well.

ATC Communications Management service (ACM)

The pilot response to an ATC instruction to change frequency shall be WILCO. If the crew is unable to comply with this data link instruction, the pilot shall revert to voice communication to inform the ATC. When an aircraft is transferred to an adjacent sector / ATS unit by data link, the pilot shall acknowledge the instruction by WILCO, and then shall contact the next sector / ATS unit by voice communication on the assigned frequency.

ATC Microphone Check service (AMC)

A "Check Stuck Microphone" instruction may be sent by an ATC in case the aircraft is inadvertently blocking a radio frequency. If the "Check Stuck Microphone" instruction relates to the radio telephony frequency currently being used, the pilot shall check that the aircraft radio equipment is not causing the blockage. If the "Check Stuck Microphone" instruction does not relate to the radio telephony frequency being used, no further actions by the pilot are required.

Construction of CPDLC Messages

The text of messages shall be composed in standard predefined message format (e.g. CPDLC message set). Normally the use of free text messages should be avoided.

Long messages or messages with multiple requests elements (multi-element messages) must not be used.

A list of the standard CPDLC messages available for the exchanges in the RIGA FIR, along with appropriate responses are presented below.

UPLINK MESSAGES

ACM uplink messages

ATC Message Content	Pilot’s Response
CONTACT [unit name] [frequency]	WILCO or UNABLE [+DUE TO WEATHER] or UNABLE [+DUE TO AIRCRAFT PERFORMANCE] or STAND BY
ERROR [error information]	NIL System-generated notification of an error.
NEXT DATA AUTHORITY [facility]	NIL System-generated notification of the next data authority
[free text]	NIL
LOGICAL ACKNOWLEDGEMENT	NIL System-generated notification that the received message is acceptable for display.
MONITOR [unit name] [frequency]	WILCO or UNABLE [+DUE TO WEATHER] or UNABLE [+DUE TO AIRCRAFT PERFORMANCE] or STAND BY

ACL uplink messages

ATC Message Content	Pilot’s Response
UNABLE	NIL
STANDBY
MAINTAIN [level]	WILCO or UNABLE [+DUE TO WEATHER] or UNABLE [+DUE TO AIRCRAFT PERFORMANCE] or STAND BY
CLIMB TO [level]
DESCEND TO [level]
PRO CEED DIRECT TO [position]
ERROR [error information]	NIL System-generated notification of an error.
SERVICE UNAVAILABLE	`NIL System-generated notification that received message is not supported.
[free text] (for additional error information)	NIL System-generated notification.
FLY HEADING [degrees]	WILCO or UNABLE [+DUE TO WEATHER] or UNABLE [+DUE TO AIRCRAFT PERFORMANCE] or STAND BY
LOGICAL ACKNOWLEDGEMENT	NIL System-generated notification that the received message is acceptable for display.
TURN [direction] HEADING [degrees]	WILCO or UNABLE [+DUE TO WEATHER] or UNABLE [+DUE TO AIRCRAFT PERFORMANCE] or STAND BY
MAINTAIN [speed]
RESUME NORMAL SPEED
SQUAWK [code]
SQUAWK IDENT
[free text]	WILCO or UNABLE [+DUE TO WEATHER] or UNABLE [+DUE TO AIRCRAFT PERFORMANCE] or STAND BY

AMC uplink message

ATC Message Content	Pilot’s Response
CHECK STUCK MICROPHONE [frequency]	NIL

DOWNLINK MESSAGES

ACM downlink messages

Pilot’s Message Content	ATC Response
WILCO	NIL
UNABLE
STANDBY
ERROR [error information]	NIL System-generated notification of an error.
NOT CURRENT DATA AUTHORITY	NIL System-generated rejection of any CPDLC message sent from a ground facility that is not the current data authority.
[free text]	NIL
CURRENT DATA AUTHORITY	NIL System-generated notification that the ground facility is now the current data authority.
LOGICAL ACKNOWLEDGEMENT	NIL System-generated notification that the received message is acceptable for display.
NOT AUTHORIZED NEXT DATA AUTHORITY	NIL System-generated notification that the ground system is not designated as the next data authority.

ACL downlink messages

Pilot’s Message Content	ATC Response
WILCO	NIL
UNABLE
STANDBY
REQUEST [level]	Any CPDLC uplink message The ATCO may accept or reject the request or ask to wait.
REQUEST DIRECT TO [position]
ERROR [error information]	NIL System-generated notification of an error.
DUE TO WEATHER	NIL Indication that the associated message is issued due to specified reason.
DUE TO AIRCRAFT PERFORMANCE
[free text] (for additional information)	NIL
LOGICAL ACKNOWLEDGEMENT	NIL System-generated notification that the received message is acceptable for display
REQUEST CLIMB TO [level]	Any CPDLC uplink message The ATCO may accept or reject the request or ask to wait.
REQUEST DESCENT TO [level]

Responding to CPDLC Messages

When a controller or pilot communicates via CPDLC, the response should be via CPDLC. When a controller or pilot communicates via voice, the response should be via voice.

Reverting from CPDLC to Voice

When an immediate response and / or action are required the air-ground communications shall revert to voice.

When it is required to clarify the meaning or the intent of any unexpected, inappropriate or ambiguous CPDLC message, the air-ground communications shall revert to voice.

When it is necessary to ensure the timely execution of an instruction issued by CPDLC, the air-ground communications shall revert to voice.

When a system generates a time-out or an error for a CPDLC message the air-ground communications shall revert to voice.

When corrective actions are required with respect to the unintended messages that have been sent using CPDLC, the air-ground communications shall revert to voice conforming to communication procedures as set out in PANS-ATM.

Message Restrictions and Error Management

If a message received is not supported by a ground system or constitutes an error to the technical rules for CPDLC communication, flight crew will receive an automatic reply indicating the nature of the error and, if applicable, required actions.

CPDLC Failure

In case of CPDLC failure, an ATC will instruct all data link equipped aircraft to revert to voice communications.

In case of on-board CPDLC failure, the pilot shall revert to voice communications and inform appropriate ATC unit.

Discontinuation of the Use of CPDLC Pilot Requests

In order to manage the sector workload, controller may require all stations or a specific flight to avoid sending CPDLC requests for a limited period of time.

Log-off

Log-off is conducted automatically on leaving the RIGA FIR. No pilot action is required.

3. Broadcasting service

The following RTF broadcasts are available for the use of aircraft in flight:

a) VOLMET broadcasts (for details see GEN 3.5.7);

b) Automatic Terminal Information Service (ATIS broadcasts) (for details see GEN 3.5.9);

c) METEO INF broadcasts (for details see GEN 3.5.9).

The language used in all broadcasts is English.

Aircraft are allowed to receive ATIS and VOLMET data via data link. This service operates through the ACARS network and supports aircraft equipped with ACARS which is ARINC 623 compliant (the provider is SITA). The D-ATIS service is available for AD RIGA. The D-VOLMET service is available for the following AD: RIGA, TALLINN (LENNART MERI), VILNIUS, STOCKHOLM (ARLANDA), HELSINKI (VANTAA), SAINT-PETERSBURG and MOSCOW (SHEREMETYEVO and VNUKOVO) (for details see GEN 3.5).

As D-VOLMET and D-ATIS are additional services, no NOTAMs concerning possible interruptions to these services will be published.

4. Language(s) used

English is used in radio communication between aircraft and ATC units.

5. Where detailed information can be obtained

Details of various facilities available for en-route traffic can be found in Part 2, ENR 4. Details of the facilities available at individual aerodromes can be found in the relevant section of Part 3 (AD). In cases where a facility is serving both en-route traffic and aerodromes, details are given in the relevant sections of Part 2 (ENR) and Part 3 (AD).

The requirements 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 ICAO documents, EC Regulations and other documents.

The main provisions are briefly summarised below:

• Aircraft operating within the area of responsibility of the Latvian ATS shall maintain radio communication in accordance with the ICAO regulations on the frequencies specified in Part 2 ENR 2.1
• When reporting positions. their geographical names or the call signs of facilities may be used. For reporting points not marked with radio aids, the 5-letter name codes are transmitted.
• If radio contact cannot be established on a primary frequency, the pilot should try on the other frequencies published for that ATS unit.
• The radio station operating on the 121.500 MHz emergency channel may use any call signs assigned to radio stations of the appropriate ATS units.
• Radio equipment to be used in aircraft registered in Latvia must be of a type approved by the Telecommunication Authority of Latvia – SJC “Electronic Communications Office”.

Post:

SJC “Electronic Communications Office”

Eksporta iela 5

Rīga, LV-1010, Latvija

Tel: +371 67333034

Fax: +371 67821275

Email:vases@vases.lv

For Aeronautical Fixed Services (Telephone) see Figure 1.

Figure 1.