ICAO: Frequently Asked Questions

What is the difference between the terms ‘Adopted’, ‘effective’ and ‘applicable’, as regards ICAO Standards and Recommended Practices?


‘Adopted’, ‘effective’ and ‘applicable’ are all terms which refer to amendments to the Annexes to the Chicago Convention which are managed through ICAO.


They specifically regard new or adjusted civil aviation Standards and Recommended Practices agreed to by States through ICAO, and how States and operators must implement them, as follows:


Adoption date


This is the actual date that the amendment is adopted by the ICAO Council’s 36 Member States. Normally this occurs in March of a given calendar year and the Council is responsible for ICAO’s Governance decisions while our full Assembly (every three years) in not in session.


Effective date


A common effective date for all amendments adopted by Council is set as four months after the last day of the Council session when the adoption took place. A standard Council session normally takes four weeks.


The effective date is the date by which States must advise ICAO that they do not approve the amendment. If more than 50 per cent of States indicate disapproval, the amendment does not become effective, but this has not yet happened in the over 70 years that ICAO has been supporting global civil aviation.


Applicability date


This is usually in November (eight months after adoption and approximately four months after the effective date) and is based on the November AIRAC* date.


By this date States should be applying the amendment unless they have notified ICAO of differences between their regulations and the ICAO Standards in the amendment. The deadline to notify differences is one month before the applicability date.


* AIRAC stands for Aeronautical Information Regulation And Control and stems from Annex 15 - Aeronautical Information Services (AIS). It defines a series of common dates and an associated standard aeronautical information publication procedure for States.

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