Symbols and abbreviations

Charts compress a three-dimensional procedure into a two-dimensional sheet. The price for that density is a symbol language. The good news: a handful of symbols covers 90% of what you will ever see.

• VOR — a hexagon or compass-rose symbol; radials run outward like spokes.
• NDB — a small circle with radiating dots; flown with the ADF needle.
• DME — distance information, usually paired with a VOR or ILS ; shown as "DME required" or DME distances along the course.
• ILS — shown as a long thin feather/arrow along the final course ( localizer ), with its frequency and identifier.

Every navaid also carries a compact frequency/identifier block — decoded line by line in Navaids and frequencies .

• Compulsory fix — a filled triangle or star; you must report/cross it.
• Non-compulsory fix — an open triangle or cross.
• Named waypoint — a five-letter name like JOGON or LORPU; in the sim it appears on the ND and in the FMC .
• IAF / IF / FAF / MAPt — the four milestone points of every approach: Initial, Intermediate, Final Approach Fix and Missed Approach Point. How they chain into a flown procedure is covered in From STAR to touchdown .

• Thick arrow with a number — the course to fly, e.g. 247°.
• Underlined altitude — fly at or ABOVE it. Overlined — at or BELOW. Both lines — exactly AT.
• MSA circle — a dashed circle giving the minimum safe altitude within (usually) 25 NM of a navaid or airport reference point.
• Grey shaded areas or peak symbols — terrain and obstacles, with their elevation.