# 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 (ea): Changes in clearance regarding route or level

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

(1) When issuing a clearance covering a requested change in route or level, the exact nature of the change shall be included in the clearance.
(2) When traffic conditions will not permit clearance of a requested change, the word ‘ UNABLE ’ shall be used. When warranted by circumstances, an alternative route or level shall be offered.

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Source: https://www.legislation.gov.uk/eur/2012/923/annex/section/8/division/SERA.8015/division/ea (the official version)
Page: https://openlegislation.uk/eu-regulation-2012-923/annex/section-8/division-SERA.8015/division-ea
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.