CAA NZ ATPL Instruments & Navaids cheat sheet

Navigation Charting, Plotting and Flight Planning Instruments

• Chart projections: Mercator (conformal, rhumb lines straight, scale increases with latitude), Lambert conformal conic (straight great circles approximately), polar stereographic.

• Great circle vs rhumb line: great circle is the shortest distance; rhumb line is constant track; difference grows with latitude and distance.

• Plotting: true track + variation (east subtract) = magnetic track; magnetic track + deviation = compass heading; account for wind to get heading.

• Wind triangle: heading and TAS vs track and groundspeed; wind correction angle = arcsin(wind speed × sin(wind angle)/TAS).

• Position reporting: lat/long, bearing and distance from a navaid, or radial/DME; plotting accuracy depends on chart scale.

• Chart symbols: airspace classes A–G, control areas, airways, MORA/MEA, transition altitude; check chart effective date and AIRAC cycle.

• Flight planning: fuel = trip + reserve + contingency + alternate + final reserve; ETOPS/EDTO rules for extended overwater operations.

• Altimetry on charts: MORA gives 1000 ft (2000 ft in mountainous terrain) clearance; MEA ensures navaid reception and obstacle clearance.

• Time/distance calculations: groundspeed = distance/time; ETA = distance/groundspeed; use the 1-in-60 rule for track error correction (60 NM/1°).