Commercial Pilot License (CPL) Practice Exam

Clear air turbulence (CAT) is primarily characterized by its occurrence at high altitudes and its association with jet streams. Jet streams are fast-flowing ribbons of air found in the upper troposphere, usually at altitudes between 20,000 and 50,000 feet. CAT often arises in clear skies, making it challenging for pilots to detect visible cues that indicate turbulence.

Pilots must be aware of CAT when flying near or within jet streams, as the wind shears in these regions can lead to sudden and unexpected turbulence, even in otherwise calm weather. The turbulence is categorized as "clear air" because it happens away from thunderstorms and cloud formations, distinguishing it from other types of turbulence that typically align with storm systems or adverse weather.

This understanding is crucial for flight planning and safety measures, as pilots must be prepared for these unpredictable conditions that can occur irrespective of stormy weather or cloud cover.