ICAO English Requirements - Aviation English

The ICAO English Language  Requirements for Pilots, Flight Crew and Air Traffic Controllers

It is now a condition of licensing that a professional pilot or air traffic controller should have demonstrated their skills in Plain English and English medium phraseology to a standard equivalent to level 4 in the ICAO universal rating scales.

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Since the 5th March 2008 it is required that all flight crew members and air traffic controllers involved in international trafficwill be able to prove their competence in English. In 2003, The International Civil Aviation Organisation (ICAO) set a deadline of March 2008 for English language proficiency at Level 4 and above for all pilots flying on international routes and also for air traffic controllers who service international airports and routes. For some States who were not able to meet the March 2008 deadline, full implementation was completed by March 2011.

The ICAO proficiency scale ranges from Level 1 to Level 6.

You can download the full chart showing ICAO levels here:

Download the ICAO levels (PDF)

Level 4 is the required level and we have included a brief summary of the skills here:

Pronunciation Structure (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.

 (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 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.


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 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.


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.

We also have the the full chart showing ICAO levels available for download

Download the ICAO levels (PDF)