Definition
Short for World Aeronautical Chart (WAC), a series of aeronautical charts produced at a scale of 1:1,000,000 that cover land areas of the world at a size and detail suitable for navigation by moderate-speed aircraft and aircraft operating at higher altitudes. They show cities, towns, principal roads, railroads, distinctive landmarks, drainage, terrain relief, visual checkpoints, and aeronautical information such as airports, airways, restricted areas, obstructions, and other pertinent data.
Plain English
A type of aviation map that covers a much larger area than a sectional chart but with less detail. It is designed for faster aircraft or longer cross-country flights, where a pilot needs to see more of the world on one sheet.
Context Anchor
Seen in aeronautical chart discussions when comparing chart types such as sectional charts, terminal area charts, and World Aeronautical Charts.
Derivation
Aeronautical' comes from the Greek 'aer' (air) and 'nautikos' (relating to ships or sailing) — literally 'sailing through the air.' A 'World Aeronautical' chart is, then, a navigation chart for flying, drawn at a scale broad enough to show large portions of the world on one sheet.
Why Pilots Care
WACs trade detail for coverage. They are useful when planning longer flights or flying faster aircraft where a sectional would require flipping through many charts, but they show fewer ground features and less detail, so they are not ideal for low-altitude visual navigation.
Intuition Check
Do not read World Aeronautical as meaning “all aviation information for the whole world.” In this context, it points to a chart type with broad coverage and less local detail.
Example Sentence 1
For the long cross-country leg over sparsely populated terrain, the pilot used a World Aeronautical Chart instead of carrying multiple sectionals.
Example Sentence 2
World Aeronautical charts are useful when planning a long cross-country flight that spans multiple sectional charts.