Navigation
Navigation tests the practical geometry of getting from A to B: chart reading, magnetism, the triangle of velocities, dead reckoning, time/fuel/distance, and radio navigation aids (VOR, DME, NDB, GNSS) at PPL level.
Charts and magnetism
Use the 1:500,000 VFR chart. Measure track in degrees true, then apply variation: variation west, magnetic best; variation east, magnetic least. Deviation is the compass error read from the compass card.
Triangle of velocities
Heading, true airspeed and wind give track and groundspeed. Wind correction angle = arcsin(crosswind/TAS); groundspeed ≈ TAS × cos(drift).
Worked example
TAS 100 kt, required track 090°T, wind 360°/20 kt. The wind is a pure crosswind from the left, so drift is arcsin(20/100) = 11.5° to the right; fly heading 078°T. Groundspeed = √(100² − 20²) ≈ 98 kt, so a 98 nm leg takes about 60 minutes.
Time, fuel and distance
Mental model: 120 kt is 2 nm per minute; 90 kt is 1.5 nm per minute. Fuel used = flow × time, then add reserves.
Radio navigation
VOR gives a radial in degrees magnetic; DME gives slant range; an NDB gives a relative bearing to the station; GNSS gives position but must be cross-checked. A VOR radial from the station is the outbound track.
Traps
Applying variation in the wrong direction; confusing heading with track; using TAS instead of groundspeed for time; and forgetting that VOR radials are magnetic, not true.