Annex 11 9th Edition m9 nd urn CORRIGENDUM - to the International Standards and Recommended Practices AIR TRAFFIC SERVICES Annex 11 to the Convention on International Civil Aviation Ninth Edition - 1990 English Version - 1. Please amendh hand Appendix 4, ATS Airspace Classifications, as follows Class D., IFR flights. Delete one of the words "advice" in the last line of the "Service providemumn. 2. P-ecord the entry of this corrigendum on page ii. C