ENR 1.6 ATS SURVEILLANCE SERVICES AND PROCEDURES

1 Surveillance Equipment

1.1 Supplementary Services
1.1.1 To provide ATS surveillance service in Tallinn FIR, including aircraft separation, cooperation requiring independent surveillance (i.e. secondary surveillance radar (SSR)) is used, given that radar coverage in given area is sufficient and the surveillance system target detection and its accuracy meet the established requirements.
1.1.2 A pilot shall know when ATS-surveillance services are provided by the use of following phrases by radar controller:
  1. “…(call sign), radar contact…”
  2. ”…(call sign), identified…”
1.1.3 Tallinn area control (ACC) operates two secondary surveillance radar (SSR) stations and wide area multilateration system (WAM).

Note: Radars are used as RSR radars.

In addition, area control (ACC) has access to surveillance information from Helsinki Hansikallio and Ergli SSR station.

1.1.4 Tallinn approach control (APP) operates two secondary surveillance radar (SSR) stations.

Note: Radars are used as TAR radars.

In addition, approach control (APP) has access to surveillance information from Helsinki Hansikallio and WAM.

1.1.5 Tartu AFIS operates wide area multilateration system (WAM).In addition, Tartu AFIS has access to surveillance information from Martna, Tallinn and Ergli SSR station.
1.2 The Application of ATS Surveillance Service
1.2.1 Surveillance radar identification is achieved according to the provisions specified by ICAO.
1.2.2 ATS surveillance service is provided in controlled airspace in areas of sufficient radar coverage. This service is defined to:
  1. provide surveillance service according to need to enhance the use of airspace, minimise delay, give direct routes and optimal flight profiles and ensure flight safety;
  2. vector departing aircraft to provide effective and smooth departure and accelerate climb to cruising level;
  3. vector aircraft to avoid possible conflict;
  4. vector arriving aircraft to provide effective and smooth approach sequence;
  5. vector aircraft to assist flight crew navigate (e.g. towards or away from radio navigation aid) and recommendations for navigation to help pilot to avoid certain airspace parts;
  6. provide separation and maintain smooth traffic flow if radio failure occurs in radar coverage;
  7. monitor air traffic, which enables neighbouring air traffic control centres and other partners who need the information about specified aircraft position reports, including major deviation from clearances given by air traffic units.
1.2.3 The following radar separation minimum between identified controlled aircraft shall be applied:
  1. 5 NM (9.3 km) in Tallinn control area (CTA) above FL95;
  2. 3 NM (5.6 km) in Tallinn terminal control area, except when greater distance is needed due to wake turbulence separation minimum during approach or departure below FL100;
1.2.4 Radar separation is used between departing and previously departed or other identified aircraft, also if there is a reason to believe that departing aircraft shall be identified at least 1 NM (1.83 km) from the end of runway and separation exists at that moment.
1.2.5 Radar separation may not be used for aircraft flying in the same holding.
1.2.6 Levels given by radar controller ensure minimum ground and obstacle clearance, except for visual departure or visual approach.
1.3 ATS Surveillance System and Air-Ground Communication Failure Procedures
1.3.1 ATS Surveillance System Failure
1.3.1.1 Besides the main system, backup ATS surveillance system is also used in Tallinn area control centre (ACC) and Tallinn approach control centre (APP). In case of main system malfunction switch to backup system shall happen without delay.
1.3.1.2 In case of total ATS surveillance system failure or loss of identification (failure of aircraft transponder and others) but radio communication with aircraft is ensured, air traffic units shall determine the positions of identified aircraft. Also they shall take the necessary measures to provide procedural separation between the aircraft flying in the area of responsibility and shall restrict controlled aircraft from entering to this area.
1.3.1.3 In case of total ATS surveillance system failure and/or loss of identification, pilots shall be informed on the main frequency of corresponding air traffic units frequency and corresponding instructions for further actions shall be given.
1.3.1.4 ATC may use emergency separation minimum, if standard procedural separation shall not be ensured immediately. Emergency separation minimums are flight levels which are separated in half of valid vertical separation minimum.
1.3.2 Air-Ground Communication Failure
1.3.2.1 In case of two-way radio communication failure, first it is determined that the receiver is in functional. ATC shall give aircraft instructions to use special position indicator (SPI), change code or to make a special manoeuvre. ATC shall monitor its implementation. If pilot fails to comply, responsible ATC shall give these instructions on every frequency that the pilot may monitor.
1.3.2.2 In case of total loss of radio communication pilot shall set squawk A7600 and follow ICAO Annex 2 compliant radio communication failure procedures according to flight phase.
1.3.2.3 In case of radio communication failure, if there is a phone on board of the aircraft, pilot may call to Tallinn air traffic control centre operational supervisor on phone +372 625 8254.
1.3.2.4 Aircraft with radio communication failure flying in controlled airspace shall continue receiving service based on ATS surveillance system until radio communication is restored or the aircraft has landed and ATC unit has received the arrival report.
1.4 Voice and CPDLC Position Reporting Requirements

To be developed.

1.5 Chart of Surveillance Coverage

To be developed.

2 Cooperation Requiring Independent Surveillance (i.e. SSR)

  General
Operating SSR transponder is in accordance with ICAO and EUROCONTROL provisions.

Except when encountering a state of emergency, pilots shall operate transponders and select modes and codes in accordance with ATC instructions.

When entering Tallinn FIR a pilot shall operate the transponder in line with guidance of ATS unit (until further instructions).
2.1 Emergency Procedures
2.1.1 The following squawk codes are internationally reserved for use in the state of emergency:
  • 7500 - unlawful interference of an aircraft;
  • 7600 - radio communication failure;
  • 7700 - emergency.
2.1.2 If the pilot of an aircraft encountering a state of emergency has previously been directed by ATC to set a specific squawk, this setting shall be maintained until otherwise advised.
2.2 Air-Ground Communication Failure and Unlawful Interference Procedures

NIL (not applicable).

2.3 System of SSR Code Assignment
2.3.1 A/3 SSR codes used for IFR flights in Tallinn FIR are assigned and managed by European Centralised SSR Code Assignment and Management System (CCAMS).
2.3.2 A/3 SSR codes used for VFR flights in Tallinn FIR are assigned and managed by Tallinn area control centre (ACC).
2.3.3 Pilot, who has not received specific instructions from ATS unit concerning the setting of the transponder, shall maintain Mode A/3 Code 2000 (until further instructions) in Tallinn FIR. Aircraft which does not receive ATS services, maintains Code 7000.
2.4 Voice and CPDLC Position Reporting Requirements

To be developed.

3 Automatic Dependent Surveillance - Broadcast (ADS-B)

  General

The basis for the use of the ADS-B system as an essential part of the surveillance chain for both air navigation service providers and aircraft operators is set out in European Commission Implementing Regulation (EU) 2023/1170.

Messages broadcast via ADS-B will be processed by ADS-B sensors and integrated into the ATS surveillance system. ADS-B surveillance-based surveillance services may be provided to aircraft transmitting ADS-B data, provided that the quality of that data meets the quality requirements established for the provision of ATS services.

Aircraft that do not comply with the requirements of the aforesaid regulation shall always transmit a value of 0 (zero) on the position quality indicators or disable ADS-B transmission. The aircraft pilot shall be responsible for ensuring the appropriate integrity and accuracy of the ADS-B information.

4 Other Relevant Information and Procedures

NIL (not applicable).