Navigation Systems
VOR, DME, ILS, ADF
For VOR know the CDI, OBS, TO/FROM logic, reverse sensing, and the cone of confusion. VOR receiver checks are required within 30 days and logged: VOT plus or minus 4 degrees, ground checkpoint plus or minus 4 degrees, airborne checkpoint plus or minus 6 degrees, and dual VOR check plus or minus 4 degrees between receivers. DME gives slant-range distance, so it reads high at altitude over the station. ILS: the localizer is four times wider than a comparable VOR course and the glideslope is normally 3 degrees; marker beacons and DME identify fixes. For ADF, magnetic bearing to the station equals magnetic heading plus relative bearing.
GNSS and RNAV
Know TSO-C129, C145, and C146 equipment, RAIM prediction (required for non-WAAS receivers, not for WAAS/SBAS receivers that provide integrity), LNAV, LNAV/VNAV (baro-VNAV), and LPV (WAAS). Approach databases must be current for the procedure and the aircraft.
Worked example
Heading 090, relative bearing 030. Magnetic bearing to the station is 090 + 030 = 120. To fly to the station, turn to 120; a bearing pointer on the 030 relative position confirms you are left of course when tracking inbound.
Trap: applying RAIM-prediction questions to WAAS-equipped aircraft, and confusing an LNAV/VNAV line of minima (barometric vertical guidance) with LPV (SBAS vertical guidance to a DA).