Navigation (General Navigation and Radio Navigation)
Navigation
This domain tests chart work, heading and track, wind triangle, time-distance-fuel, magnetic variation and deviation, plus VOR, NDB, GPS and ILS. The exam expects practical calculations and correct interpretation of radio aids.
Core rules
- True course is measured on the chart; true heading applies wind correction; magnetic heading applies variation; compass heading applies deviation.
- Variation east is subtracted from true to get magnetic; variation west is added. Deviation comes from the compass card.
- Wind triangle: use TAS, wind velocity and required track to find heading and ground speed.
- VOR gives bearing from the station; NDB gives relative bearing; GPS gives position and track; ILS gives lateral and vertical guidance.
Worked example
True course 090°, TAS 120 kt, wind 360°/20 kt. The wind from the north pushes the aircraft south of track, so crab north by about 10°: true heading 080°. Ground speed is about 118 kt. With 1°E variation, magnetic heading is 079°. The reasoning is to apply wind correction first, then variation.
Traps
Do not apply variation to a magnetic heading twice. Do not use IAS as TAS without correction. Do not confuse VOR radial with bearing to the station. A GPS track is ground track, not heading.