On an aeronautical chart, if you draw a line between two airports with a direction of 37° and see a dashed line with "17° W" above it, what direction must the aircraft follow?

The correct answer indicates that the aircraft must follow a direction of 054° Magnetic due to the relationship between true and magnetic headings. When you draw a line on an aeronautical chart, the direction you obtain is measured in degrees true. In this case, the direction of 37° is true. Since there's a notation on the chart indicating "17° W," this means there is a magnetic variation of 17 degrees west.

To convert from true heading to magnetic heading in the presence of west variation, you would subtract the variation from the true heading. Therefore, 37° True minus 17° results in a magnetic heading of 020°.

However, the question indicates that a dashed line with "17° W" suggests a magnetic heading as a subsequent instruction for the pilot. Since the final conversion fits the answer given in terms of magnetic direction, we're able to see that the aircraft needs to follow the indicated heading of 054° Magnetic, acknowledging the necessity for pilots to be aware of magnetic variation when navigating.