ICAO English Proficiency Testing: The Six Levels Explained

ICAO English proficiency is a person’s rated ability to speak and understand English for radiotelephony, scored on ICAO’s six-level scale from Level 1 (Pre-elementary) to Level 6 (Expert). Level 4 (Operational) is the minimum for pilots, air traffic controllers and aeronautical station operators in international operations. The level a test reports is the lowest of six skill ratings, so a test has to rate each skill separately.

This post is for heads of training, quality managers and exam officers at aviation training organizations that host, sell or verify English proficiency assessments, and for small companies building aviation English courses or tests. It explains the scale, how regulators treat testing and retesting, and what a test’s design and records should show. It does not teach English or coach candidates.

The facts below come from ICAO pages, ICAO Doc 9835 (second edition, 2010, read in a copy hosted by SKYbrary), FAA Advisory Circular 60-28B, EASA’s Part-FCL point FCL.055, the UK CAA and Transport Malta, read in November 2026. Exact wording is marked (quoted). ICAO sells Annex 1, so this post did not read it. This is not licensing or legal advice; authorities differ and rules change, so check your competent authority.

Key takeaways

• ICAO English proficiency is rated on six levels, Level 4 (Operational) is the minimum, and the reported level is the lowest of six skill ratings, never an average.
• Retest intervals depend on the source: EASA’s FCL.055 and the UK CAA give 4 years at Level 4 and 6 years at Level 5, SKYbrary’s summary of ICAO Annex 1 gives 3 and 6, and FAA AC 60-28B names no interval.
• A defensible test shows design evidence: a construct tied to the ICAO scale, voice-only and face-to-face tasks, trained and independent raters, equivalent secure versions, recordings and records.
• ICAO recognition of a test through its Aviation English Language Test Service is not approval, lasts 3 years, covers Levels 3 to 5 only, and does not by itself show that your authority accepts the test.
• Where the texts read are silent, such as how long to keep test records, only your competent authority can answer, so get the answer in writing.

What are the six ICAO English proficiency levels?

ICAO’s rating scale runs from Level 1 (Pre-elementary) to Level 6 (Expert). Level 4 is Operational, Level 5 is Extended and Level 6 is Expert. Raters score six skills: pronunciation, structure, vocabulary, fluency, comprehension and interactions. The scale covers speaking and listening only, and it does not test operational knowledge.

ICAO Doc 9835, paragraph 2.3.4.1, calls Operational Level 4 “the minimum level acceptable to ensure safe operations” (quoted). The manual’s glossary also says “Knowledge of operational procedures is not tested in language tests.” (quoted) A language test is therefore not a phraseology or technical exam. FAA AC 60-28B lists the same six criteria.

Doc 9835 paragraph 4.5.7 says the scale is not an “equal interval” scale (paraphrased). Moving from Level 2 to Level 3 can take longer than moving from Level 4 to Level 5, which matters if you sell preparation courses. This post does not reproduce the level descriptors. They sit in Annex 1, Appendix 1 and Doc 9835, chapter 4.

Who must reach Level 4, and how often is it retested?

ICAO sets Level 4 as the minimum for pilots, air traffic controllers and aeronautical station operators in international operations. Regulators then add their own rules. EASA’s FCL.055 and the UK CAA retest Level 4 every 4 years and Level 5 every 6 years, while Level 6 holders are largely exempt. The FAA guidance read names no interval.

The ICAO Aviation English Language Test Service FAQ describes the program, and ICAO’s language proficiency pages name Level 4 as the minimum operational level. In the US, FAA Advisory Circular 60-28B, dated June 2, 2017, says “the FAA AELS should be applied to no less than the ICAO Operational Level 4” (quoted). It treats anyone authorized to conduct certification, training, testing or checking as an evaluator, and it does not require a specific language test (paraphrased).

In Europe, FCL.055 of Part-FCL says the endorsement must show the language, the level and the validity date (paraphrased). The text read is point FCL.055 as replaced by Commission Regulation (EU) 2019/1747, in the copy held on legislation.gov.uk, so check EASA’s current Easy Access Rules. Its acceptable means of compliance, read in ED Decision 2020/005/R, says the authority may run the assessment or delegate it to language testing bodies (paraphrased).

Why do published sources give 3, 4 or 9 years?

They describe different rule layers. Doc 9835 paragraph 4.4.7 says Annex 1 holds a Standard for recurrent testing and a Recommended Practice for the schedule (paraphrased). SKYbrary’s summary of Annex 1 gives 3 years at Level 4. EASA and the UK CAA set 4. The table shows each source side by side.

The FAA circular says a person who does not meet the standard may be subject to reexamination under 49 U.S.C. 44709 (paraphrased). The table is this post’s reading, as of November 2026. Track the validity date printed on the endorsement your authority issued, because that date is what you will be audited against.

Why does the lowest of the six ratings decide the level?

ICAO’s scale is not averaged. Doc 9835 paragraph 4.5.11 says the overall rating “is determined by the lowest rating assigned” (quoted). A candidate rated 5 on five skills and 4 on one is Level 4. A test must therefore rate each skill on its own and keep all six ratings.

Take an illustrative candidate rated 5 for pronunciation, 4 for structure, and 5 for vocabulary, fluency, comprehension and interactions. The average is 4.83, which rounds to 5. The ICAO result is Level 4. A spreadsheet or platform that stores one averaged score reports the wrong level.

Transport Malta’s notice for language testing bodies (PEL Notice 94, version 6.0, 11 August 2025) says the documented rating process must state that the “final score is the lowest of the scores in each of the six ICAO language proficiency skills” (quoted). EUROCONTROL’s ELPAC self-assessment, which ICAO has not endorsed, describes the same rule with two assessors, no compensatory marking and a third assessor to resolve disagreements. Do not borrow rules from other grading schemes: our guide to CBTA competencies, observable behaviors and grading covers a separate system.

Pro tip: Keep Six Ratings, Not One Level. Store every assessor’s six ratings, the rule applied and the computed level as separate fields. When an appeal or audit asks why a candidate received Level 4, you can recompute the result from the raw ratings instead of trusting one stored number.

What must an ICAO English proficiency test show about its design?

A test must show evidence, not claims. The sources read ask for a construct tied to the ICAO scale, voice-only and face-to-face settings, trained and consistent raters, equivalent secure versions, recordings and records. How binding each item is depends on your authority. The table sorts the items by the source that states them.

Read the Transport Malta rows as one authority’s current notice, not a universal rule. The PEL Notice 94 guidance for language testing bodies is useful as a worked example of what an authority can ask for. None of the sources read names an approved platform. Task formats, delivery tools and scheduling stay your choice.

If any part of your language test runs online, keep it apart from exam rules. The Part-147 and Part-FCL conditions in our overview of what regulators expect from online assessment in aviation training concern other exams, so do not assume they answer language testing questions.

How do raters stay consistent?

Raters stay consistent through initial and maintenance training, a shared rating scale, multiple raters and documented agreement checks. Doc 9835’s glossary names those measures as the counter to rater unreliability. ELPAC’s self-assessment says two accredited assessors rate its speaking paper, with a third resolving disagreements.

The mechanics of calibration, such as anchor samples and agreement statistics, are general to any rated assessment. Our post on instructor and examiner standardization covers them. Whatever method you pick, record the date, the samples and the outcome of each session.

What does ICAO recognition of a test mean?

ICAO recognition means ICAO assessed an aviation-specific test against its language proficiency requirements and Doc 9835 and found it conforming. The FAQ does not call this approval or endorsement. Recognition lasts 3 years, covers Levels 3 to 5 only and does not by itself show that your authority accepts the test.

The FAQ says general English tests and licensing exams are outside the service, and that marketing material is not acceptable evidence. It adds: “Making claims about a test is not enough: all claims must be supported with appropriate evidence.” (quoted) Ask any vendor for the evidence behind each claim, and confirm acceptance with your authority.

Pro tip: Separate Teachers From Testers. If your organization both teaches and tests aviation English, build the assessor roster so that nobody rates a candidate they have taught, and write that rule into your procedures. Both the EASA acceptable means of compliance and Transport Malta’s notice treat independence as part of test design.

What records should an English proficiency test leave behind?

Each test should leave a record that lets someone else rebuild the result: who was tested, which test version, when, who rated, six ratings per rater, the final level, any recording and the endorsement date. No source read sets a retention period for these records, so ask your authority how long to keep them.

The table lists a record set. The fields marked “Malta” come from PEL Notice 94 version 6, sections 10.1, 10.2 and 11.2. The others are this post’s suggestions, not requirements.

What should you do next?

List every English proficiency assessment you host, sell or rely on, and check four things for each: whether it rates six skills separately and applies the lowest-rating rule, who rates and how they are trained and kept independent, what each test records, and which authority’s interval and endorsement date apply. Write the gaps down and take them to your competent authority.

When you compare platforms, ask how each would capture six ratings per assessor, apply the lowest-rating rule and link a recording. SimpliAssess’s published features page lists item banking, test management, examinee management, schedule management, analytics and reporting, and an API-first design, but its published pages do not describe speaking or audio items, rater scoring, rubrics or recording, so put those questions to any vendor.

For reminders, our guide to recertification and recurrent testing covers expiry notices and grace periods in general. SimpliTrain’s aviation page describes a certification monitor with automated alerts at 90, 60 and 30 days before safety certifications expire, but it does not mention English proficiency endorsements, so confirm any such use with the vendor.

Frequently asked questions

What is ICAO Level 4 English?

ICAO Level 4 (Operational) is the minimum rating on ICAO’s six-level scale. Doc 9835 calls it “the minimum level acceptable to ensure safe operations” (quoted). It applies to pilots, air traffic controllers and aeronautical station operators in international operations. A candidate reaches Level 4 only if the lowest of six skill ratings is at least 4.

How often must ICAO English proficiency be retested?

It depends on the authority. EASA’s FCL.055 and the UK CAA give 4 years at Level 4 and 6 years at Level 5, with Level 6 largely exempt. SKYbrary’s summary of ICAO Annex 1 gives 3 years at Level 4. FAA AC 60-28B names no interval. Track the validity date on your endorsement and confirm with your authority.

Can the six skill ratings be averaged?

No. Doc 9835 says the overall rating is determined by the lowest rating assigned, not the average or aggregate. A candidate scoring 5 on five skills and 4 on one is Level 4. Any test or platform that stores only an averaged score can report the wrong level.

Does the FAA require a specific English proficiency test?

The circular read does not. FAA AC 60-28B sets a standard of no less than ICAO Operational Level 4 and has evaluators, meaning people authorized to conduct certification, training, testing or checking, judge it during their normal events. It does not name a required test. Check current FAA guidance, because the edition read is dated June 2, 2017.

Does ICAO approve English proficiency tests?

No approval is described. ICAO’s Aviation English Language Test Service offers formal recognition of aviation-specific tests that meet its language proficiency requirements, and its FAQ does not call this approval or endorsement. Recognition lasts 3 years and covers Levels 3 to 5. The FAQ does not say any regulator must accept a recognized test.

Can a native English speaker skip the test?

Not automatically. UK CAA guidance says an examiner awarding Level 6 must be in no doubt that the candidate is an expert speaker, and the examiner keeps evidence of the candidate’s language background. If the examiner has doubts, no level is recorded and the candidate is referred for formal assessment. Check your own authority’s route.