Navigation
Charts and position
Understand chart projections - Mercator (rhumb lines straight, scale varies with latitude) and Lambert conformal conic (great circles nearly straight). Know how to plot a position from VOR radials, NDB bearings, and DME arcs, and remember that VOR radials are from the station.
Dead reckoning
Be fluent with the triangle of velocities: true heading, track, wind vector, and groundspeed. Traps include confusing track made good with required track, and forgetting magnetic variation versus deviation. Helicopters often fly low level, where terrain and wind gradients make groundspeed estimates less reliable.
Radio navigation and GNSS
Know the principles of VOR, DME, NDB/ADF, and GNSS, including RAIM and integrity monitoring. Understand that GNSS is subject to jamming and spoofing and that a fallback means of navigation may be required.
Worked example
True track 090°, wind 360°/20 kt, TAS 100 kt. Headwind component 20 kt gives groundspeed 80 kt; the crosswind requires a wind correction angle of about 11° into wind. Rule of thumb: wind correction angle ≈ (crosswind ÷ TAS) × 60 degrees, so 20/100 × 60 ≈ 12°, close enough for planning.