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This glossary is written for virtual airline and flight simulation use within Virtual Air Canada Airline. It is not intended as a real-world aviation reference.
The International Civil Aviation Organization is a specialized agency of the United Nations established by the Convention on International Civil Aviation (the Chicago Convention) in 1944. ICAO sets the international standards and recommended practices that govern virtually every aspect of civil aviation, from airspace structure and air traffic management to aircraft certification, crew licensing, security, and environmental standards. Member states are expected to align their national regulations with ICAO standards, ensuring that international aviation operates on a consistent, interoperable basis worldwide. Among the most widely recognized outputs of ICAO are the four-letter airport codes (such as CYVR for Vancouver or EGLL for London Heathrow) and the standardized formats for meteorological reports, flight plans, and phraseology. ICAO also defines the standard atmosphere model used for aircraft performance calculations, categorizes approach types and minima, and coordinates the allocation of frequency bands and airspace classifications. Its 193 member states contribute to the ICAO Assembly and Council, which develop Annexes to the Chicago Convention covering topics from rules of the air to accident investigation.

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In Virtual Airline Operations

ICAO standards are the foundation for how Virtual Air Canada Airline operates. ICAO airport codes are used throughout SimBrief flight planning, ATC communications on VATSIM and POSCON, and all PIREP submissions. Standard ICAO phraseology is the expected communication style on online networks, and familiarity with ICAO procedures for flight plans, weather decoding, and airspace classification directly improves the quality of virtual operations.
  • METAR - Meteorological Aerodrome Report
  • ILS - Instrument Landing System
  • ISA - International Standard Atmosphere