# 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 SERA.13015: SSR transponder Mode S aircraft identification setting

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

(a) Aircraft equipped with Mode S having an aircraft identification feature shall transmit the aircraft identification as specified in Item 7 of the ICAO flight plan or, when no flight plan has been filed, the aircraft registration.
(b) Whenever it is observed on the situation display that the aircraft identification transmitted by a Mode S-equipped aircraft is different from that expected from the aircraft, the pilot shall be requested to confirm and, if necessary, re-enter the correct aircraft identification.
(c) If, following confirmation by the pilot that the correct aircraft identification has been set on the Mode S identification feature, the discrepancy continues to exist, the controller shall take the following actions:
(1) inform the pilot of the persistent discrepancy;
(2) where possible, correct the label showing the aircraft identification on the situation display; and
(3) notify the next control position and any other unit concerned using Mode S for identification purposes that the aircraft identification transmitted by the aircraft is erroneous.

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Source: https://www.legislation.gov.uk/eur/2012/923/annex/section/13/division/SERA.13015 (the official version)
Page: https://openlegislation.uk/eu-regulation-2012-923/annex/section-13/division-SERA.13015
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.