Turbulence is the part of flying that frightens passengers most and worries pilots least, and that gap exists for a good reason: what feels dramatic in the cabin is, to the aircraft, a routine bump in an invisible medium. An aeroplane does not fly through solid air; it flies through a fluid that moves, swirls, and changes speed, and turbulence is simply the aircraft moving through uneven patches of that fluid.

This guide explains the main kinds of turbulence, why modern aircraft handle them comfortably, and what actually keeps you safe, which is simpler than most passengers expect.