Several days ago was the latest incident of a flight encountering Cat, or clear air turbulence. Cat is a disturbance of air masses around the jet stream. In the latest event a JAL 747 en route from Manilia to Tokyo encountered cat while in cruise portion of flight. Because this is the most active part of the flight for passengers, naturally this is how so many people got injured. In this case 47 people was injured. There was no damage to the aircraft. In most cases there never is damage to the aircraft. Passengers don't fare to well. Most passenger injuries are because they don't have their seat belt on. Then there are cases of people standing up in the aisle. Airlines are required to make a briefing to passengers when they level off in flight. The crew is suppose to brief passengers if they're going to remain in their seat they should always keep their seat belts on. This is your only protection from turbulence because cat remains very difficult to detect. Cat is a very rare type of turbulence, but when it does happened it can be a terrifying few seconds. I personally experience cat only once in my 22 years of flying. For more information on turbulence view this free video link .