Description

Advisory airspace is an airspace of defined dimensions, or designated route, within which air traffic advisory service is available.

An advisory route is a designated route along which air traffic advisory service is available.

(ICAO Annex 11: Air Traffic Services)

Further Reading

• ICAO Annex 11: Air Traffic Services
• ICAO Doc 4444: Procedures for Air Navigation Services - Air Traffic Management (PANS-ATM)