The Enroute Low and High altitude charts provide aeronautical information for instrument navigation in the low and high airway structures. Enroute Low and High Altitude charts provide aeronautical information for instrument navigation in the low and high airway structure of the Canadian Domestic Airspace, the airspace over foreign territory and international waters in which Canada accepts responsibility for the provision of air traffic services and other areas required for military use. The primary purpose of Enroute charts is to depict radio navigation data to provide rapid and precise location and identification of information requisite to radio instrument navigation.
Enroute High Altitude charts (HI) depict aeronautical navigation information, airways system, special use airspace, communication stations critical for flight in the high level structure. Vertical coverage is from 18,000' asl and above. The charts are printed back-to-back on eight sheets. Complete set includes all of Canada and Greenland.