# Commission Regulation (EU) No 139/2014 of 12 February 2014 laying down requirements and administrative procedures related to aerodromes pursuant to Regulation (EC) No 216/2008 of the European Parliament and of the Council (Text with EEA relevance), Division: ADR.OPS.A.020 Common reference systems


For the purpose of air navigation, the aerodrome operator shall use:
(a)) the World Geodetic System – 1984 (WGS-84) as the horizontal reference system;
(b)) the mean sea level (MSL) datum as the vertical reference system;
(c)) the Gregorian calendar and coordinated universal time (UTC) as the temporal reference systems.

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Source: https://www.legislation.gov.uk/eur/2014/139/annex/IV/division/1/division/4n1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2014-139/annex-IV/division-1/division-4n1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.