ICAO English Language Requirements
The International Civil Aviation Organisation (ICAO) has mandated that on the 5th of March 2011 all pilots of international aircraft and air traffic controllers serving international airports or routes must be certified to have attained level 4 ICAO English or higher.


  • The International Civil Aviation Organisation (ICAO) has introduced language proficiency requirements for air traffic controllers and pilots with the intent of improving the level of language proficiency in aviation around the globe and reducing the frequency of communication errors.
  • Historically, insufficient English language proficiency on the part of the flight crew or the controller has contributed to a number of accidents and serious incidents, see here for more details.
  • The new Language Proficiency requirements apply to all international air traffic communicators in the civil sector should they be native English speakers or non-native English speakers. ICAO Doc 9835 states:

“It should not be solely non-native speakers who must work to improve air traffic communications…”
“…Native speakers of English, too, have a fundamentally important role to play in the international efforts to increase communication safety.”

ICAO Requirements

  • The requirements for language proficiency for operational personnel are detailed in ICAO Annex 1 – Personnel Licensing (here).
(image embedded from TCI 1 Oct 2010)

ICAO Language Proficiency Rating Scale

(image embedded from Skybrary 29 Sep 2010)

Reassessment Requirements

ICAO mandated a requirement of levels 4, 5 or 6. However they also require that the language skills of any pilots and controllers rated at:

  • Level 4 - need to be reassessed every three years,
  • Level 5 - need to be reassessed every six years, and
  • Level 6 - need no further assessment of English language ability (considered fluent).

Goal of the Requirements

The advantages of an elevated international standard of aviation English are:

  • Improved communicative understanding of all parties.
  • Non-standard phraseology is less likely to cause confusion.
  • Increased situational awareness of flight crews in relation to other aircraft, both in the air and on the ground.
  • A higher standard of communication internationally.
  • A broader range of English comprehensions by flight crews in their profession.
1. ICAO (2004). Document 9835. Retrieved from ICAO on 2 Oct 2010.
2. ICAO (2007). ICAO annex 1 – personnel licensing. Retrieved from ICAO on 30 Sep 2010.
3. Skybrary (2010). English Language Proficiency Requirements. Retrieved from Skybrary on 1 Oct 2010.
4. Skybrary (2010). Air-Ground Voice Communications. Retrieved from Skybrary on 2 Oct 2010.

Want to know more?

Aviation Knowledge History of English in Aviation
ICAO full summary History
ICAO **Annex 1** – Personnel Licensing - Language Proficiency Rating Scale;
ICAO **Annex 10** - Aeronautical Communications, Volume II;
ICAO Doc 9835 AN/453Doc 9835.
ICAO Resolution A36-11Attachment A: Proficiency in the English language for Radiotelephony;
ICAO Resolution A36-11Attachment B: Guidelines for the Development of a Language Proficiency Implementation Plan;
ICAO Language Proficiency Requirements FAQ.

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