ICAO
International Civil Aviation Organization
Last updated: April 20, 2026 · Maintained by Aviatr Editorial Team
What is ICAO?
ICAO (International Civil Aviation Organization) is a United Nations specialised agency that sets global standards for safe, orderly, and efficient international air transport. EASA, the FAA, and every national aviation authority in ICAO's 193 contracting states base their regulations on ICAO Standards and Recommended Practices (SARPs).
How is ICAO used?
Pilots encounter ICAO standards every day without realising it. The four-letter airport code EDDB for Berlin, the phonetic alphabet Alpha to Zulu, the mayday distress call, the standardised instrument approach chart format, and the ICAO English Language Proficiency Level 4 requirement all trace back to ICAO Annexes. When national regulations conflict with ICAO, states file differences that pilots must check before cross-border flights — documented in each country's Aeronautical Information Publication (AIP). ICAO publishes 19 Annexes covering subjects from personnel licensing (Annex 1) to security (Annex 17); Annex 1 alone defines the privileges and minimum hours of every pilot license recognised worldwide, harmonised through EASA Part-FCL for Europe. ICAO also coordinates the global flight-plan format used in every commercial operation today, and its quadrennial Assembly sets strategic priorities that flow down into EASA rulemaking cycles. Pilots preparing for any EASA theoretical exam will find dozens of questions rooted directly in ICAO Annex text.