ICAO English Language Proficiency Requirements
All pilots operating on international routes and all air traffic controllers who communicate with foreign pilots need to have their English language proficiency formally assessed. The ICAO language proficiency requirement requires that pilots and air traffic controllers be able to communicate proficiently using both ICAO phraseology (ICAO Doc. 9832) and plain English (ICAO Doc. 9835).
The minimum language level for licensing purposes is ICAO Level 4. To be assessed at ICAO Level 4 or above, a pilot or air traffic controller must achieve Level 4 in all six of the ICAO skill areas: Pronunciation, Structure, Vocabulary, Fluency, Comprehension and Interactions.
A speaker is proficient to Level 4 if the ratings for the following criteria are met:
Pronunciation: (Assumes a dialect and/or accent intelligible to the aeronautical community.)
Pronunciation, stress, rhythm, and intonation are influenced by the first language or regional variation but only sometimes interfere with ease of understanding.
Structure: (Relevant grammatical structures and sentence patterns are determined by language functions appropriate to the task.)
Basic grammatical structures and sentence patterns are used creatively and are usually well controlled. Errors may occur, particularly in unusual or unexpected circumstances, but rarely interfere with meaning.
Vocabulary:
Vocabulary range and accuracy are usually sufficient to communicate effectively on common, concrete, and work-related topics. Can often paraphrase successfully when lacking vocabulary in unusual or unexpected circumstances.
Fluency:
Produces stretches of language at an appropriate tempo. There may be occasional loss of fluency on transition from rehearsed or formulaic speech to spontaneous interaction, but this does not prevent effective communication. Can make limited use of discourse markers or connectors. Fillers are not distracting.
Comprehension:
Comprehension is mostly accurate on common, concrete, and work-related topics when the accent or variety used is sufficiently intelligible for an international community of users. When the speaker is confronted with a linguistic or situational complication or an unexpected turn of events, comprehension may be slower or require clarification strategies.
Interactions:
Responses are usually immediate, appropriate, and informative. Initiates and maintains exchanges even when dealing with an unexpected turn of events. Deals adequately with apparent misunderstandings by checking, confirming, or clarifying.