Navigation, airspace and charts
Airspace structure
Classes A to G: A–C are controlled, D is controlled aerodrome airspace, E is controlled with reduced requirements, F is special-use and G is uncontrolled - but uncontrolled does not mean unregulated. Know control zones and control areas, prohibited (P), restricted (R) and danger (D) areas, military low-jet routes, mandatory broadcast zones and CTAF aerodromes. Your pre-flight airspace check uses the appropriate chart plus AIP/ERSA and current NOTAMs.
Charts and position
Visual terminal and visual navigation charts, and en-route charts, carry airspace boundaries, radio frequencies and navaids. Position is expressed in latitude/longitude, which is why mental arithmetic with minutes matters. Be able to convert: true versus magnetic headings using variation, east or west; grid north versus true north; scale. Global navigation satellite systems give position, but the aircraft still needs your see-and-avoid and your airspace discipline.
Worked example / rule of thumb
One minute of latitude = 1 NM (and one degree ≈ 60 NM ≈ 111 km). 1 NM = 1.852 km. On a 1:250,000 chart, 1 cm = 2.5 km. A position 3 minutes north of a boundary is roughly 3 NM away - close enough to matter at 120 m.
Traps
Treating class G as a free-for-all; swapping prohibited and restricted meanings; planning from an out-of-date chart; ignoring a NOTAM that activates a restricted area; applying variation in the wrong direction.