Air turbulence: That sudden stomach-drop feeling; why the body reacts before the brain

A perfectly ordinary flight can change in seconds. One moment, the cabin is quiet and people are watching a movie, sleeping or chatting. Then the aircraft gives a sudden jolt, drops slightly or moves sideways, and the stomach seems to follow it down.That strange sinking sensation can be startling, even for people who are otherwise comfortable flying. Some passengers immediately grip their seats. Others feel their heart race, muscles tighten or breathing become quicker. A few may develop nausea, dizziness or sweating.The important thing to understand is that the sensation does not necessarily mean the aircraft is suddenly falling. Turbulence is a change in the movement of air around the aircraft, and the human balance system is extremely sensitive to changes in movement.