When the plane started shaking violently on a Delta flight from Salt Lake City to Amsterdam last week, some passengers thought it was going to crash.
The jet had hit severe turbulence, flinging people into the ceiling, and service carts across the cabin. One passenger said it felt like an earthquake. The plane was forced to make an emergency landing in Minneapolis, where 25 people were taken to the hospital.
It was just the latest in a series of recent turbulence incidents resulting in injuries, hospitalizations and even a death. A 73-year-old man died of a heart attack during severe turbulence on a flight from London to Singapore last year.
Turbulence, caused by disturbances in the atmosphere, is one of the most unpredictable weather phenomena for pilots.
Air flows like water gushing down a river: undisturbed it runs smoothly, but if it encounters an obstacle, like a boulder, it becomes turbulent. Mountains and storms act like boulders in a river, altering the way air moves.
