Investigations of several major airline accidents and accidents over the last few years show that a lack of language proficiency by pilots and air traffic controllers has been a contributing factor. Although a majority of pilots and controllers are familiar with the ICAO standardized phraseology, experience show that when an abnormal situation arises or an event occurs that requires a pilot to exchange information with a “foreign” controller in plain language, the ability to communicate sometimes diminishes greatly. The result of the communication, rather than being a helpful resolution of uncertainty, may be the introduction of further confusion and, ultimately, a complete breakdown of awareness that leads to a catastrophe.

ICAO has specified six different levels of proficiency in six different criteria (see the ICAO language proficiency rating scale). To be operational the licence holder is required to pass a minimum of level four on all six criteria.

The six criteria where the applicant will be assessed are: pronunciation, structure, vocabulary, fluency, comprehension and interactions. The lowest score in any of the six criteria is the final score of the language assessment.