Navigation
Scope
Navigation tests charts, headings, wind triangle, time-distance-fuel, and Philippine airspace references. You must convert between true, magnetic, and compass headings and plan a safe VFR route.
Core rules
- True heading is measured from true north; magnetic heading applies variation; compass heading applies deviation.
- Wind correction angle (WCA) compensates for crosswind. Heading = true course ± WCA; groundspeed = distance ÷ time.
- Fuel = flow rate × time; always include reserve and alternate.
- Use AIP Philippines charts, NOTAMs, and current frequencies; do not rely on expired chart data.
Worked example
True course 090°, TAS 100 kt, wind 180°/20 kt. The wind is from the right and blows the aircraft left, so crab right. WCA = arcsin(20/100) ≈ 12°, giving true heading 102°. The wind is almost across track, so groundspeed ≈ √(100² − 20²) = 98 kt. For a 98 nm leg, time ≈ 1.0 h. Apply variation and deviation to get the compass heading; do not stop at true heading.
Traps
Adding the WCA in the wrong direction. Using TAS as groundspeed with a strong wind. Applying variation and deviation in the wrong order. Planning fuel only for the outbound leg. Using a chart without checking airspace and NOTAMs.