Most airline passengers have experienced in-flight turbulence. In some cases, it can be severe. From 2009 to 2022, the US National Transportation Safety Board reported that because of turbulence, there were 163 injuries requiring hospitalization on commercial airlines and 38 deaths on private planes. In the US alone, turbulence is estimated to cost $150 million to $500 million annually from structural damage to planes, flight delays, and injuries, according to the National Center for Atmospheric Research (NCAR).
Turbulence is often associated with the towering cumulonimbus clouds of storm systems. Air within the clouds mixes with outside air of different temperature, pressure, and velocity, triggering atmospheric instabilities. But such turbulence is usually detectable in advance so the worst impacts are avoided. What can be more dangerous is clear-air turbulence (CAT), which is generated by chaotic instabilities at aircraft cruising altitudes. Unlike turbulence linked to clouds or storms, CAT cannot be detected ahead of time with onboard radar equipment. And it can produce large enough vertical accelerations of an aircraft to lift passengers from their seats.
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