Meteorology
Weather knowledge for the flight deck
Candidates must understand the atmosphere's structure and standard atmosphere, pressure and altimetry, temperature and humidity, stability and instability, cloud formation, precipitation, visibility, wind and its variation with height, and the main air masses and fronts. Learn the formation of thunderstorms, icing, turbulence, wind shear and microbursts, and the hazards they pose. Understand METAR, TAF, SIGMET, AIRMET and the meaning of the Q codes and trend forecasts.
Traps in questions
A common trap is confusing indicated altitude with true altitude in cold air - the altimeter over-reads in cold air, so the aircraft is lower than indicated. Another is assuming that a high QNH means high terrain clearance everywhere. Questions also test the difference between a front and a trough, and the conditions that favour cumulonimbus development.
Worked example
"Flying at an indicated 5,000 ft in air colder than ISA; is the true altitude higher or lower?" Answer: lower - cold air is denser, so the altimeter over-reads; apply a cold-temperature correction. Rule of thumb: from high to low, look out below.
Key points
- In cold air the altimeter over-reads; true altitude is lower.
- Know the conditions favouring cumulonimbus and icing.
- Understand METAR, TAF, SIGMET and trend forecasts.
- Wind shear and microbursts are critical low-level hazards.
- Distinguish fronts, troughs and air masses.