How to use a navigation plotter

There are many types of navigation plotters. The most common used in VFR navigation is the sectional plotter, which typically will enable you to measure nautical miles and statute miles on both sectional charts and world aeronautical charts (WAC). We’ll typically only be using the nautical mile sectional chart scale; be careful to ensure that you are reading this scale when measuring distances.

We’ll use a sectional chart excerpt that is depicted in Figure 27 of the FAA’s Airmen Knowledge Test Supplement for Sport, Recreational and Private Pilot. Be forewarned; these sectional chart excerpts are not to scale. You’ll need to use the scale printed on the excerpt to accurately measure distance.

Draw your course line Lay the straight edge of the plotter on the sectional chart across to your departure and destination airports, or checkpoints if the route exceeds the plotter’s edge. In this example, we’ll plot a course from Jamestown Airport to Cooperstown airport. CourseLine
Measure Distance Line up the start of the nautical mile sectional scale with your departure airport and read the mileage to your destination airport. In this case the distance between Jamestown Airport and Cooperstown Airport is 36.5 nautical miles (NM). MeasureDistance
Determine True Course Using the lines of longitude on the sectional course as a reference to true north, determine the true course between the departure and destination airports. Study the examples below using the fixed plotter or rotation plotter.
Fixed Plotter
Position the center hole (grommet) over a line of longitude and the drawn course line, and align the plotter with the course line. Look at the top of the compass arc and interpret the true course that is in the direction of flight. In this example, we are flying from Jamestown Airport to Cooperstown Airport, which is a northeasterly direction. A true course of 040° is a northeasterly course. The reciprocal course, 220°, is a southwesterly course, and would be the true course if we were fly from Cooperstown Airport to Jamestown Airport. TrueCourseFixedPlotter
Rotating Plotter
Position the plotter’s straight edge on the drawn course line. Rotate the compass until the north arrows are parallel to the lines of longitude on the sectional chart. Read the course on the compass that is aligned with the arrow on the plotter that is aligned with the drawn course line.