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How to Use a Plotter on a Sectional Chart

A plotter is a special ruler pilots use to measure distances and angles on FAA sectional charts. An FAA sectional chart is a map, with a 1:500,000 scale, which depicts airports and terrain over a specific area of the U.S. and is the primary tool for visual navigation planning for slow- to medium-speed aircraft. Approximately 40 slightly-overlapping sectional charts cover the entire United States. If a plotter's scale is 1:500,000, a pilot can use it directly on a sectional chart to measure straight distances. Additionally, plotters normally include protractors to measure angles and thereby directions of flight.

Things You'll Need

Plotter
Sectional chart

Instructions

- 1
  Draw a straight line from the beginning of your straight leg of flight to the end.
- 2
  Put the plotter's zero mark on the start point, align the plotter along the straight line and read off the distance measurement at the end point. For example, a distance of approximately 7.3 inches on a sectional chart should show up as 50 nautical miles on your plotter. To have an accurate reading, ensure the plotter's scale is 1:500,000 or says on it "Sectional."
- 3
  Place the center of the protractor section of the plotter over an intersection of your straight line and a printed longitude or latitude line. If it's latitude, ensure the 90-degree and 270-degree lines are aligned directly on it. If it's longitude, ensure the 0-degree and 180-degree lines are directly on it.
- 4
  Read off at which angle your straight line leaves the edge of the protractor in the direction of the endpoint of the straight line. For example, if the line is halfway between the 70-degree and 80-degree marks, your true heading for this leg is 75 degrees.

Aviation