Knowledge Test Supplement - Watch the Scale!

Earlier this year the FAA updated the Private Pilot Test Supplement. This is the book that contains all the figures and charts that are referenced in the Private Pilot Knowledge Test. This introduced a number of issues. One issue is that the scale on the sectional chart excerpts does not match the scale on a real chart and consequentially your plotter can’t be used to directly measure distance. The previous test supplement, although it didn’t match perfectly, was relatively close. On the new test supplement, figure 21 is significantly different than the normal scale. You can see in this picture that if you used your plotter, a distance of 10 NM on the figure would be measured as only 7 NM as shown on a plotter. This would be enough to throw any calculations off and lead to answering the test question incorrectly. Each figure has a unique scale on the side of the chart that must be carefully checked in order to determine the accurate distance.