COMMUNICATION AND NAVIGATION SERVICESRESPONSIBLE SERVICEThe service responsible for providing communication and navigation service in the Republic of Lithuania is the Oro navigacija AB.ORO NAVIGACIJA ABHEAD OF TECHNICAL DEPARTMENTBalio Karvelio Str. 25LT-02184 VILNIUS, LITHUANIATel.:+370 706 94 516Email:info@ans.ltURL:www.ans.ltThe services are provided in accordance with the provisions contained in the following documents:Annex 5–Units of Measurement to be used in Air and Ground Operations;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 4444–Rules of the Air and Air Traffic Services;Doc 8259–Manual on the Planning and Engineering of the Aeronautical Fixed Telecommunication Networks;Doc 8071–Manual on testing of radio navigation aids.Differences to these provisions are detailed in section GEN 1.7.AREA OF RESPONSIBILITYCommunication and navigation services are provided for the entire Vilnius .Communication and navigation services for en-route and at international airports in the Vilnius FIR are provided by the Oro navigacija AB, except at Šiauliai . Air Base of the Lithuanian Air Force is responsible for communication and navigation services at Šiauliai AD.TYPES OF SERVICERadio Navigation ServicesThe following types of radio navigation aids are available:/ Non-directional Beacon (); Direction-Finding Station ();Instrument Landing System (, /); Doppler Omnidirectional Radio Range ();Distance-Measuring Equipment ().All radio navigation aids are dual installations and equipped with secondary power supply.The maximum switch-over time to the standby transmitter correspond requirements set in ICAO Annex 10, Volume I; if these requirements cannot be met, the maximum switch-over time will be published as a remark within AD part of the relevant aerodrome, under item AD 2.19.Radio navigation facilities will not be available for navigation purposes during the maintenance period.The usable radio navigation aids are indicated in ENR 4 Radio navigation aids/systems and AD part of the relevant aerodrome AD 2.19 item Radio navigation and landing aids.The change-over point between radio navigation aids of an route is normally mid-way point between these aids or at the point of the change of track, if not otherwise published. Radio navigation aids are regularly flight checked and calibrated.Voice and/or data link servicesMobile ServiceUnless otherwise notified, the aeronautical stations maintain a continuous watch on their stated frequencies during the published hours of service.An aircraft should normally communicate with the air ground-control radio station which exercises control in the area being overflown. Crew should maintain continuous monitoring on the appropriate frequency of the control station and should not abandon the monitoring without informing the control radio station, except in an emergency.Fixed ServiceMessages to be transmitted over the are accepted only if:they satisfy the requirements of Annex 10, Vol. II, Chapter 3, 3.3;they are prepared in the form specified in Annex 10;the text of an individual message does not exceed 1800 signs.Data Link Services - Controller-Pilot Data Link Communications (CPDLC)GeneralProvision of in the Vilnius FIR is based on the requirements of the Commission Regulation (EC) No.2023/1770. 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  285.The following data link services are provided in this airspace:Data Link Communications Initiation Capability (DLIC);ATC Clearances and Information (ACL);ATC Communications Management (ACM);ATC Microphone Check (AMC).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 situationsFlight PlanPilot intending to conduct CPDLC communications within the Vilnius 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 UseWithin the Vilnius FIR CPDLC exchanges may only be conducted when the aircraft is under control of Vilnius ACC.In the area of responsibility of Vilnius 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-onThe data link address for Vilnius is EYVC.Normally log-on should be initiated 10 to 15 minutes prior to entering the Vilnius 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 Vilnius 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 . 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 MessagesThe 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 Vilnius FIR, along with appropriate responses are presented below.UPLINK MESSAGESACM uplink messagesATC Message ContentPilot’s ResponseCONTACT [unit name] [frequency]WILCOorUNABLE [+DUE TO WEATHER]orUNABLE [+DUE TO AIRCRAFT PERFORMANCE]orSTAND BYERROR [error information]NILSystem-generated notification of an error.NEXT DATA AUTHORITY [facility]NILSystem-generated notification of the next data authority.[free text]NILLOGICAL ACKNOWLEDGEMENTNILSystem-generated notification that the received message is acceptable for display.ACL uplink messagesATC Message ContentPilot’s ResponseUNABLE NILSTANDBY MAINTAIN [level]WILCOorUNABLE [+DUE TO WEATHER]orUNABLE [+DUE TO AIRCRAFT PERFORMANCE]orSTAND BYCLIMB TO [level]DESCEND TO [level]PROCEED DIRECT TO [position]ERROR [error information]NILSystem-generated notification of an error.SERVICE UNAVAILABLENILSystem-generated notification that received message is not supported.[free text] (for additional error information)NILSystem-generated notification.FLY HEADING [degrees]WILCOorUNABLE [+DUE TO WEATHER]orUNABLE [+DUE TO AIRCRAFT PERFORMANCE]orSTAND BYLOGICAL ACKNOWLEDGEMENTNILSystem-generated notification that the received message is acceptable for display.[[free text]WILCOorUNABLE [+DUE TO WEATHER]orUNABLE [+DUE TO AIRCRAFT PERFORMANCE]orSTAND BYAMC uplink messageATC Message ContentPilot’s ResponseCHECK STUCK MICROPHONE[frequency]NILDOWNLINK MESSAGESACM downlink messagesPilot’s Message ContentATC ResponseWILCONILUNABLE STANDBY ERROR [error information]NILSystem-generated notification of an error.NOT CURRENT DATA AUTHORITYNILSystem-generated rejection of any CPDLC message sent from a ground facility that is not the current data authority.[free text]NILCURRENT DATA AUTHORITY NILSystem-generated notification that the ground facility is now the current data authority. LOGICAL ACKNOWLEDGEMENTNILSystem-generated notification that the received message is acceptable for display.NOT AUTHORIZED NEXT DATANILSystem-generated notification that the ground system is not designated as the next data authority.ACL downlink messagesPilot’s Message ContentATC ResponseWILCONILUNABLE 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]NILSystem-generated notification of an error.DUE TO WEATHERNILIndication that the associated message is issued due to specified reason.DUE TO AIRCRAFT PERFORMANCE[free text] (for additional error information)NILLOGICAL ACKNOWLEDGEMENTNILSystem-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 MessagesWhen 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 VoiceWhen 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 ManagementIf 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.Pilot requests via CPDLC should not be send using free text messages.CPDLC FailureIn 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 RequestsIn order to manage the sector workload, a controller may require all stations or a specific flight to avoid sending CPDLC requests for a limited period of time.Log-offLog-off is conducted automatically on leaving the VILNIUS FIR. No pilot action is required.Broadcasting ServiceAutomatic Terminal Information Service (ATIS) is available for the use of aircraft in flight.Aircraft are allowed to receive ATIS via data link. This service operates through ACARS network and supports aircraft equipped with ACARS which is ARINC 622/623 compliant. Full details are given in section GEN 3.5. is available at the EYVI AD only. D-ATIS being an additional service, no NOTAM concerning possible interruptions will be published.Language usedEnglish and Lithuanian.An indication of where detailed information can be obtainedDetails of various en-route facilities can be found in Part 2, section ENR 4.Details of the aerodrome facilities can be found in Part 3 (AD 2). In cases where the facility is serving both en-route and aerodromes, details are given in the relevant sections of Part 2 (ENR) and Part 3 (AD).REQUIREMENTS AND CONDITIONSThe requirements and general conditions under which the communication and navigation 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 list of the main provisions is briefly summarized as follows:Aircraft operating within the area of responsibility of the ATS shall maintain radio communication in accordance with the ICAO regulations on frequencies as specified in the section ENR 2.1.When reporting points their geographical names or the call signs of the facility are to be used. For the reporting point not marked by radio aids the 5-letter name codes are transmitted.If the pilot is not able to establish radio contact on the primary frequency, he should try other frequencies as published for that ATS unit.Radio communication facilities marked with "" have possibility to measure a magnetic bearing of aircraft ().Radio station operating on the 121.500 emergency channel may use any call sign assigned to radio stations of the appropriate ATS units.MISCELLANEOUSNIL.