Navigation
Core framework
Navigation for the helicopter pilot covers chart reading, dead reckoning, and the use of radio navigation aids. You must understand latitude/longitude, the magnetic versus true north relationship (variation), and how to compute heading, track, groundspeed and time.
Concepts to master
Dead reckoning: track, heading, wind correction, groundspeed. The triangle of velocities. Variation (chart) and deviation (compass) - "variation east, magnetic least." Map reading: scale, contours, symbols. Understand the difference between true track, magnetic track and compass heading. For helicopters, low-level navigation relies heavily on visual references and map reading.
Traps
- Confusing variation (geographic) with deviation (instrument).
- Applying the wind correction in the wrong direction.
- Misreading scale on a chart (1:500,000 means 1 cm = 5 km).
- Forgetting that groundspeed depends on wind, not just airspeed.
Rule of thumb
"Variation east, magnetic least; variation west, magnetic best." Add westerly variation to true to get magnetic; subtract easterly.
Worked example
True track 090°, variation 5°E. Magnetic track = 090° − 5° = 085°. If deviation is 2°E, compass heading = 085° − 2° = 083°. Always apply variation then deviation in sequence.