# 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.14025: Principles governing the identification of ATS routes other than standard departure and arrival routes

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

(a) Use of ATS route designators in communications
(1) In voice communications, the basic letter of a designator shall be spoken in accordance with the spelling alphabet as defined in Table S14-2.
(2) Where the prefixes K, U or S are used, they shall, in voice communications, be spoken as follows:
(i) K KOPTER
(ii) U UPPER
(iii) S SUPERSONIC
(b) The word ‘ kopter ’ shall be pronounced as in the word ‘ helicopter ’ and the words ‘ upper ’ and ‘ supersonic ’ as in the English language.

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Source: https://www.legislation.gov.uk/eur/2012/923/annex/section/14/division/SERA.14025 (the official version)
Page: https://openlegislation.uk/eu-regulation-2012-923/annex/section-14/division-SERA.14025
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.