{
  "url": "https://openlegislation.uk/eu-regulation-2012-923/annex/appendix-4",
  "json_url": "https://openlegislation.uk/eu-regulation-2012-923/annex/appendix-4.json",
  "legislation": "eur/2012/923",
  "legislation_title": "Commission Implementing Regulation (EU) No 923/2012 of 26 September 2012 laying down the common rules of the air and operational provisions regarding services and procedures in air navigation and amending Implementing Regulation (EU) No 1035/2011 and Regulations (EC) No 1265/2007, (EC) No 1794/2006, (EC) No 730/2006, (EC) No 1033/2006 and (EU) No 255/2010 (Text with EEA relevance)",
  "legislation_url": "https://openlegislation.uk/eu-regulation-2012-923",
  "path": "annex/appendix/4",
  "kind": "appendix",
  "number": "4",
  "heading": null,
  "text": "ATS airspace classes — services provided and flight requirements\n(SERA.6001 and SERA.5025(b) refers)\nWhen the level of the transition altitude is lower than 3 050 m (10 000 ft) AMSL, FL 100 should be used in lieu of 10 000 ft. Competent authority may also exempt aircraft types, which for technical or safety reasons, cannot maintain this speed.\nPilots shall maintain continuous air-ground voice communication watch and establish two-way communication, as necessary, on the appropriate communication channel in RMZ.\nAir-ground voice communications mandatory for flights participating in the advisory service. Pilots shall maintain continuous air-ground voice communication watch and establish two-way communication, as necessary, on the appropriate communication channel in RMZ.\nClass\nType of flight\nSeparation provided\nService provided\nSpeed limitation\nRadio communication capability requirement\nContinuous two-way air-ground voice communication required\nSubject to an ATC clearance\nA\nIFR only\nAll aircraft\nAir traffic control service\nNot applicable\nYes\nYes\nYes\nB\nIFR\nAll aircraft\nAir traffic control service\nNot applicable\nYes\nYes\nYes\nVFR\nAll aircraft\nAir traffic control service\nNot applicable\nYes\nYes\nYes\nC\nIFR\nIFR from IFR\nIFR from VFR\nAir traffic control service\nNot applicable\nYes\nYes\nYes\nVFR\nVFR from IFR\n(1) Air traffic control service for separation from IFR;\n(2) Air traffic control service, VFR/VFR traffic information (and traffic avoidance advice on request)\n250 kts IAS below\n3 050 m\n(10 000 ft) AMSL\nYes\nYes\nYes\nD\nIFR\nIFR from IFR\nAir traffic control service, traffic information about VFR flights\n(and traffic avoidance advice on request)\n250 kts IAS below\n3 050 m\n(10 000 ft) AMSL\nYes\nYes\nYes\nVFR\nNil\nAir traffic control service, IFR/VFR and VFR/VFR traffic information (and traffic avoidance advice on request)\n250 kts IAS below\n3 050 m\n(10 000 ft) AMSL\nYes\nYes\nYes\nE\nIFR\nIFR from IFR\nAir traffic control service and, as far as practical, traffic information about VFR flights\n250 kts IAS below\n3 050 m\n(10 000 ft) AMSL\nYes\nYes\nYes\nVFR\nNil\nTraffic information as far as practical\n250 kts IAS below\n3 050 m\n(10 000 ft) AMSL\nNo\nNo\nNo\nF\nIFR\nIFR from IFR as far as practical\nAir traffic advisory service; flight information service if requested\n250 kts IAS below\n3 050 m\n(10 000 ft) AMSL\nYes\nNo\nNo\nVFR\nNil\nFlight information service if requested\n250 kts IAS below\n3 050 m\n(10 000 ft) AMSL\nNo\nNo\nNo\nG\nIFR\nNil\nFlight information service if requested\n250 kts IAS below\n3 050 m\n(10 000 ft) AMSL\nYes\nNo\nNo\nVFR\nNil\nFlight information service if requested\n250 kts IAS below\n3 050 m\n(10 000 ft) AMSL\nNo\nNo\nNo",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "F",
      "label": "F1",
      "text": "Substituted by Commission Implementing Regulation (EU) 2016/1185 of 20 July 2016 amending Implementing Regulation (EU) No 923/2012 as regards the update and completion of the common rules of the air and operational provisions regarding services and procedures in air navigation (SERA Part C) and repealing Regulation (EC) No 730/2006 (Text with EEA relevance)."
    },
    {
      "type": "footnote",
      "label": "f1",
      "text": "When the level of the transition altitude is lower than 3 050 m (10 000 ft) AMSL, FL 100 should be used in lieu of 10 000 ft. Competent authority may also exempt aircraft types, which for technical or safety reasons, cannot maintain this speed."
    },
    {
      "type": "footnote",
      "label": "f2",
      "text": "Pilots shall maintain continuous air-ground voice communication watch and establish two-way communication, as necessary, on the appropriate communication channel in RMZ."
    },
    {
      "type": "footnote",
      "label": "f3",
      "text": "Air-ground voice communications mandatory for flights participating in the advisory service. Pilots shall maintain continuous air-ground voice communication watch and establish two-way communication, as necessary, on the appropriate communication channel in RMZ."
    }
  ],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eur/2012/923/annex/appendix/4",
    "retrieved_at": "2026-11-01T14:49:10.260453+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}