Certified Flight Instructor - Flight Instructor Airplane Practice Exam

When converting from magnetic course to true course, a pilot should?

1. Add easterly variation regardless of heading.

2. Add westerly variation regardless of heading.

3. Subtract easterly variation when on a heading of 360°.

4. Add deviation to account for magnetic interference.

The correct answer is: Add easterly variation regardless of heading.

To convert from magnetic course to true course, a pilot must consider magnetic variation, which is the difference between magnetic north and true north. Magnetic variation can be either east or west, depending on the geographic location and the specific magnetic declination in that area. When adding easterly variation, it means that the magnetic north is located east of true north. Therefore, to convert from a magnetic course (which is based on magnetic north) to a true course (which is based on true north), the pilot adds the easterly variation. This adjustment is necessary to align the magnetic direction with true direction accurately. In contrast, if there is westerly variation, the pilot would subtract this from the magnetic course to arrive at the true course. This reflects that magnetic north is west of true north. The other choices center around variations or deviations that are either irrelevant or incorrect for the context of the question, as they do not accurately represent the proper method for converting a magnetic course to a true course. The emphasis on adding the correct type of variation ensures the pilot calculates the accurate navigation path effectively.