{
  "url": "https://openlegislation.uk/eu-regulation-2011-1332/article-2",
  "json_url": "https://openlegislation.uk/eu-regulation-2011-1332/article-2.json",
  "legislation": "eur/2011/1332",
  "legislation_title": "Commission Regulation (EU) No 1332/2011 of 16 December 2011 laying down common airspace usage requirements and operating procedures for airborne collision avoidance (Text with EEA relevance)",
  "legislation_url": "https://openlegislation.uk/eu-regulation-2011-1332",
  "path": "article/2",
  "kind": "article",
  "number": "2",
  "heading": "Definitions",
  "text": "For the purposes of this Regulation the following definitions shall apply:\n(1) ‘airborne collision avoidance system (ACAS)’ means an aircraft system based on secondary surveillance radar (SSR) transponder signals which operates independently of ground-based equipment to provide advice to the pilot on potential conflicting aircraft that are equipped with SSR transponders;\n(2) ‘airborne collision avoidance system II (ACAS II)’ means an airborne collision avoidance system which provides vertical resolution advisories in addition to traffic advisories;\n(3) ‘resolution advisory (RA) indication’ means an indication given to the flight crew recommending a manoeuvre intended to provide separation from all threats or a manoeuvre restriction intended to maintain existing separation;\n(4) ‘traffic advisory (TA) indication’ means an indication given to the flight crew that the proximity of another aircraft is a potential threat.",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eur/2011/1332/article/2",
    "retrieved_at": "2026-11-01T14:49:41.423922+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."
}