Three weather - related deaths since January , FAA says . At least two of the three were victims not wearing seat belts . Turbulence is caused by quick changes in air movement . `` The majority of injuries actually happen to flight attendants , '' Dorr said . Air movements from ` ` clear - air '' turbulence are hard to detect .
Three weather - related deaths since January , FAA says . At least two of the three were victims not wearing seat belts . Turbulence is caused by quick changes in air movement . Air movements from ` ` clear - air '' turbulence are hard to detect .