How are airline callsigns assigned?

Three things are to be considered when assignig an airline a new ICAO three letter code.

  • The three letter code must be unique to the aircraft operator
  • The R/T designator (callsign) must not cause confusion with other operators flying in the same area, preferably at most three syllables long and it must be pronounceable in at least one of the following languages; English, French, Spanish or Russian.
  • Since there are many operators that have “airline” or “airways” in their name, that word is usually avoided in the R/T designator as it easily causes confusion.