Meteorology and Flight Planning
Weather knowledge required
Candidates must interpret METAR, TAF, SPECI, SIGMET, AIRMET, and significant weather charts, and understand the hazards: thunderstorms, icing, turbulence, wind shear, low visibility, and volcanic ash. Traps include misreading TAF validity periods and change groups (BECMG, TEMPO, FM), confusing prevailing visibility with RVR, and forgetting that SIGMET covers phenomena hazardous to all aircraft while AIRMET covers lighter hazards.
Flight planning
Flight planning combines route, altitude, fuel, weather, NOTAMs, and performance. Key concepts: minimum fuel, final reserve, alternate fuel, contingency fuel, and the effect of wind and temperature on range. Traps include treating the alternate as always required or never required, and ignoring NOTAMs affecting the destination or alternate.
Worked example
A TAF reads: 'FM1200 25015KT 9999 SCT030 TEMPO 1200/1400 4000 TSRA BKN015CB.' The prevailing conditions from 12:00 are good, but temporary thunderstorms with 4 km visibility and cumulonimbus are expected between 12:00 and 14:00. A flight arriving at 13:00 must plan for the TEMPO conditions, including alternate and fuel considerations. A candidate who reads only the prevailing group has missed the hazard.
Rule of thumb
Read the whole TAF: validity, prevailing group, every change group, and the time window. Then apply the worst credible condition to your arrival time.