Meteorology
Weather for RPA operations
Small RPA are more sensitive to wind, turbulence and precipitation than conventional aircraft. Candidates must understand how pressure, temperature and humidity determine air density, how stability affects turbulence, and how local effects such as thermals, rotor near buildings and valley winds influence low-level flight. Know the difference between mean wind and gusts, and the significance of wind shear near the surface.
Concepts to master
Learn to interpret a METAR and a TAF, including wind direction and speed, visibility, cloud and weather groups. Understand the formation of cumuliform cloud and thunderstorms, the hazards of icing, and the effect of precipitation on propellers and sensors. Know how fog and mist form and how they affect visibility and camera performance. Understand the sea breeze cycle and the diurnal variation of wind and turbulence, and know that the calmest period is often early morning.
Common traps
Questions often expect the candidate to distinguish true wind from indicated wind on a moving platform, or to recognise that a gust spread matters more than the mean wind for a light aircraft. Another trap is assuming a forecast is valid for a specific hour rather than a period.
Rule of thumb
Compare the gust spread and the aircraft's demonstrated wind limit, not just the mean wind. Worked example: a METAR reporting wind 250 degrees at 8 knots gusting 20 knots means a gust spread of 12 knots; for an aircraft limited to 10 knots of wind, the mean is acceptable but the gusts are not, so the flight should be postponed or replanned.