Navigation
What the Navigation domain tests
The CAA NZ Instrument Rating Navigation examination checks that you can plan and conduct IFR flights in NZ airspace using the navigation aids and PBN specifications published in current AIP New Zealand. Questions test chart interpretation, navigation-system performance, heading and groundspeed calculations, and recognition of when a system no longer meets the required standard.
Core rules and concepts
- IFR navigation in NZ is chart-based: use AIP NZ enroute charts, terminal area charts and instrument approach charts. Check chart effective dates and NOTAMs before flight.
- Conventional aids: a VOR gives a magnetic radial; DME gives slant range; an NDB gives a relative bearing. Convert relative bearing to magnetic bearing with MH + RB = MB, then apply the reciprocal where needed.
- PBN: know RNP APCH, RNP AR APCH and RNAV(GNSS). Distinguish LNAV, LNAV/VNAV and, where published, LPV minima. RNP AR requires specific approval and training.
- GNSS integrity: RAIM prediction is required where the route or approach depends on GNSS. Check NOTAMs for GPS interference and RAIM outages.
- Alternate planning must consider navigation-aid availability, GNSS NOTAMs, weather minima and fuel.
Worked example
Track 090°M, TAS 120 kt, wind 200°M/30 kt. Max drift = 30/120 × 60 = 15°. Wind angle to track = 110°, so crosswind ≈ 28 kt and tailwind ≈ 10 kt. Drift = sin⁻¹(28/120) ≈ 14° right. Heading = 090° − 14° = 076°M. Groundspeed ≈ 120 × cos14° + 10 ≈ 126 kt. Show the sign convention and give magnetic heading, not true.
Traps
Using true instead of magnetic; treating a VOR radial as a QDM without checking variation; forgetting DME slant-range error at high altitude or short range; assuming GNSS is available without RAIM; and confusing RNP APCH with RNP AR APCH. Check whether minima are advisory or binding.