World aeronautical chart

A World Aeronautical Chart (WAC) is a type of aeronautical chart used for navigation by pilots flying primarily moderate speed aircraft and aircraft operating at high altitudes. They are produced at a scale of 1:1,000,000 (approximately 1 inch = 13.7 nautical miles or 16 statute miles).

These charts are similar to sectional charts and the symbols are the same except there is less detail due to the smaller scale, and because of this, it is seldom used for visual flight rules flight. WACs show topographic information, airports and radio navigational aids. They are primarily useful for strategic flight planning, where a comprehensive view of the entire flight area is useful.

These charts are revised annually except several Alaskan charts and the Mexican/Caribbean charts which are revised every 2 years. Australian WAC charts are amended every 3 to 5 years.

A set of 12 WACs covers the continental United States and 8 others cover Alaska. Canadian airspace is covered by a set of 18 WACs. The 43 Australian WACs are indexed according to a geographic name or a corresponding 4-digit number. .

Unlike sectional charts, North American WACs are named according to an international "grid system" having a combination of letters and numbers. For example, WAC CF-16 covers the Pacific Northwest, and E-15 covers the British Columbia area. Letters progress from A at the north pole to U at the southern tip of Argentina. The numbers generally progress from 1 at the Greenwich meridian and increasing to the east, to a maximum of 29, depending upon the number of charts required at that latitude.