The ICAO approved Chart Ruler is used for accurate measuring and is fundamental to the success of any work. This metric system ruler is the most important tool for you to achieve best results.

These plastic ICAO Chart Rulers are graduated in both statute and nautical miles for use with 1:1,000,000 and 1:500,000 scale aeronautical charts. Widely used by students and licensed aviators everywhere, they are excellent tools for navigation training exercises and real-world navigation applications. Each ruler also provides, on its reverse side, a multitude of Conversion Factors, VHF Reception Distances, Standard Time Conversions to UTC, Time Equivalencies, Flight Plan Sequences, and an Aviation Gasoline Conversion table showing the weight, in pounds at 15ºC, of incremental volumes of gasoline up to 100 litres.