Aeronautical Information and Charts
The AIS system
ICAO Annex 15 governs aeronautical information services. The core products are the AIP (Aeronautical Information Publication), NOTAMs, AIC (Aeronautical Information Circulars) and the integrated aeronautical information package. Know the difference: AIP is permanent information; NOTAM is temporary or urgent; AIC is advisory and does not establish requirements.
Charts
En-route charts, SID/STAR charts, approach plates and aerodrome charts each show specific information. Know chart symbols: obstacles, minimum safe altitudes, transition levels and MSA. The transition altitude/level distinction is a classic exam trap: transition altitude is where climbing aircraft change to standard pressure; transition level is where descending aircraft change to QNH.
Traps
- Confusing transition altitude with transition level.
- Assuming AIC changes a rule - it does not.
- Treating a NOTAM as permanent information.
- Misreading chart minimum altitudes as clearance altitudes.
Worked example
An approach chart shows an MSA of 3,500 ft. That is the minimum safe altitude for the sector, not a clearance altitude; the pilot must still comply with the cleared altitude. Rule of thumb: AIP = permanent, NOTAM = temporary, AIC = advisory.