According to an article I found today, from next March pilots who fly overseas will be required to pass an English language competency test, The Test of English for Aviation. The article suggests that this test will present quite a challange for the many Chinese pilots who speak little or no English.
Some Chinese airlines, China Southern Airlines, are requiring their pilots to take English classes for six days each month.
Apparently there is also a shortage of examiners who speak both English and Mandarin, and who are familiar with civil aviation.