Navigation
Navigation tests chart reading, dead reckoning, the wind triangle and radio-navigation aids.
Charts and direction
A 1:500,000 chart is standard for VFR navigation; 1 cm is 5 km. True direction is measured from grid or true north; magnetic direction is affected by variation. Variation east means magnetic north is east of true north: magnetic heading = true heading − easterly variation. Deviation is the compass error on a particular heading; the compass swing card gives it.
Dead reckoning
For each leg calculate true course, apply wind to get true heading and groundspeed, convert to magnetic, then apply deviation to get compass heading. ETA = distance / groundspeed. Fuel = rate × time. Update the log at waypoints; do not rely on a single fix.
Radio navigation
VOR gives a radial from the station; the CDI centres when the selected radial matches. ADF gives relative bearing to an NDB. DME gives slant range. GPS gives position, track and groundspeed, but RAIM and database currency matter; do not let the GPS replace map reading and heading checks.
Worked example
True course 000°, TAS 100 kt, wind 270°/20 kt. The wind is from the left, so crab left: WCA = arcsin(20/100) ≈ 11.5°, true heading 348.5°. Groundspeed = √(100² − 20²) ≈ 98 kt. With 5°E variation, magnetic heading = 348.5 − 5 = 343.5°M. For 60 nm, time = 60/98 h ≈ 36.7 min; at 30 L/h, fuel ≈ 18.4 L.
Traps
Applying variation to the track instead of the heading; using TAS instead of groundspeed for ETA; treating wind as blowing 'to' a direction; and ignoring compass deviation after calculating magnetic heading.