The purpose of the ICAO language proficiency requirements is
In short, language should be a tool to identify and help solve a potential problem before it becomes a disaster, rather than being one more attention-demanding obstacle.
Over 800 people lost their lives in three major accidents. In each of these seemingly different types of accidents, accident investigators found a common contributing element: insufficient English language proficiency on the part of the flight crew or a controller had played a contributing role in the chain of events leading to the accident.
In addition to these high-profile accidents, multiple incidents and near misses are reported annually as a result of language problems, instigating a review of communication procedures and standards worldwide. Such concern was heightened after a 1996 mid-air collision in which 349 passengers and crew members were killed in an accident in which insufficient English language proficiency played a contributing role.