Why is a world aeronautical chart (wac) necessary when flying long distances?

When flying long distances, a world aeronautical chart (WAC) for the determination of height, position,alternative landing areas,airspace boundaries and radio frequencies.

Explanation:

For those aircraft flying at higher distances, WAC is used for the purpose of navigation. This chart is very helpful in finding current position, alternate routes, safe heights for flying,etc. It also helps in choosing the best alternate route for reaching the desired location. It provides the person flying at higher distances with that of radio frequencies and airspace boundary.

Strategic planning can be done for flights with this chart. Using this chart we can view the whole area of flying. There is a revision of these charts every year but for the areas like  Mexico and Caribbean since the revision takes place once in 2 years.    

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