# 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), Division (a): Alerting service shall be provided by the air traffic services units:

Extent: E+W+S+N.I.

(1) for all aircraft provided with air traffic control service;
(2) in so far as practicable, to all other aircraft having filed a flight plan or otherwise known to the air traffic services; and
(3) to any aircraft known or believed to be the subject of unlawful interference.

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Source: https://www.legislation.gov.uk/eur/2012/923/annex/section/10/division/SERA.10001/division/a (the official version)
Page: https://openlegislation.uk/eu-regulation-2012-923/annex/section-10/division-SERA.10001/division-a
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.