The target population of this course book is air traffic control students. However, the course book could also serve as an English training material for in-service pilots and controllers in their preparation for International Civil Aviation Organization (ICAO) language proficiency test. The goal of this course book is to help students improve their English for communication of non-routine situations in air ground radiotelephony by providing them with common expressions and vocabulary. Standard phraseologies for routine situations are not covered herein. With ICAO Language Proficiency Requirements as guidelines，the book tries to address the most imaginable events in air traffic control operations. Non-routine situations are indefinite，and the language for such situations can never be covered in a book.