Navigation
This domain checks that you can read the charts controllers and pilots share, interpret radio navigation aid outputs, apply PBN/GNSS concepts, and handle position reporting. Questions often present a fix described by radial and distance, a chart minimum, or a report whose content must be assessed.
Charts
- Enroute low/high altitude charts, SIDs, STARs and instrument approach charts. Know the plan view, profile view and minimum sector altitude box.
- Minimum sector altitude (MSA) gives at least 1000 ft obstacle clearance within 25 NM of the reference point, usually divided into sectors. It is not a cleared level.
- Minima on approach charts: DA/DH for precision, MDA for non-precision, and the missed approach point.
Radio navigation aids
- VOR: gives magnetic radial from the station; line-of-sight, so range falls with altitude. Errors include scalloping and terrain/reflection effects.
- DME: slant range, so it reads high overhead the station; error matters mainly close in and at high altitude.
- NDB/ADF: bearing to the station, subject to night effect, thunderstorm static and coastal refraction.
- ILS: localizer gives lateral guidance, glide path typically 3°, protected by sensitive and critical areas that must be kept clear.
GNSS and PBN
RNAV allows flight on any desired path; RNP adds on-board performance monitoring and alerting. RAIM checks integrity with limited satellites. Waypoints have five-letter names; terminal procedures often use fly-by and fly-over waypoints.
Position reporting
A position report contains identification, position, time, flight level, next position and ETA. ADS-C can replace voice reporting where implemented.
Worked example
An aircraft reports "40 DME on the 045 radial" of a VOR. Reasoning: it is northeast of the station at 40 NM slant range; the true ground distance is slightly less. The track is the aircraft's, not the radial; the radial describes the bearing from the station. If the next fix is on the 090 radial at 40 DME, the aircraft must turn right.
Traps
Confusing radial (from the station) with bearing to the station; using MSA as an assigned level; forgetting DME slant error; treating an RNP value as accuracy only rather than containment with alerting.