ATPL Navigation Practice Questions - Airline Transport Pilot Licence Navigation Exam

A great circle has a constantly changing true track (except when along the Equator or a meridian), while a rhumb line maintains a constant true track. A rhumb line represents the shortest distance between any two points on the Earth's surface. A great circle is a straight line on a Mercator projection chart, whereas a rhumb line is curved. A rhumb line always spirals toward the equator, eventually forming a circle around it.