Navigation
The Earth and coordinates
Know latitude, longitude, great circles and rhumb lines, and the difference between them: a great circle is the shortest path, a rhumb line keeps a constant track. Understand magnetic variation and deviation, and the sequence true course → true heading → magnetic heading → compass heading. The trap is applying variation in the wrong direction: variation east is magnetic least, so you subtract easterly variation when converting from true to magnetic.
Charts and plotting
Learn to read the VFR chart symbols, airspace boundaries, obstacles and reporting points. Practise plotting a course, measuring distance against the scale, and computing time from distance and groundspeed. Know the meaning of the 1:500 000 scale used on Brazilian VFR charts: 1 cm equals 5 km.
Dead reckoning and wind
Compute wind correction angle and groundspeed using the wind triangle. Learn the headwind and tailwind effects on range and endurance: a headwind always costs more than the equivalent tailwind gains. That asymmetry is a favourite exam question.
Worked example
True course 090°, variation 10° W, deviation +2°. Variation west is magnetic best, so magnetic heading = 090 + 10 = 100°, then compass heading = 100 + 2 = 102°. Check the sign convention every time before answering.
Radio navigation and GNSS
Understand the basic principles of VOR, DME and GNSS, and the limitations of GNSS - signal availability, integrity and the need for a backup. Know that a GPS track is not the same as heading when there is wind.