From time to time people sometimes hear the term wind shear, & this has a tendency to sends shivers to people who suffer anxiety, or fear of flying. Many people don't quite understand what it is.  Basically, it's when you have a certain burst of wind that shifts direction & speed. It can come as a form of horizontal , or vertical shear. Its most hazardous doing take off & landing. I also like to emphasize its more of a danger if you are caught by surprise from it. But any good pilot knows to expect it when they get those clues such high surface winds, or approaching thunderstorms, or inversion layer. Also, air traffic controllers are required to give a warning to pilots too. As an airline pilot we fly through wind shear on regular basis. Anytime we fly in strong gale force winds, or even when the winds are gusting, you should expect some type of shear. We take routine precaution such as bump up are airspeed for speed protection on takeoff & landing. We also, take longer runways. Two days ago we just witness a accident which is believe to have been associated with windshear involving a FedEx Cargo airplane. It was a MD-11 which is a off spring from the DC-10. This airplane was trying to land in Narita, Japan. It initially touch down on one wheel, & bounce up in the air before the left wing hit the ground & the airplane cartwheel & exploded. Two pilots died. My hearts go out to their families. I fly FedEx sometimes to work, & know how professional & well trained their pilot group are. Although Fed Ex had several accidents in the last 37 years, this is the first one that was fatal . The MD-11 airplane has some what of a checker past. The airplane was never popular with the airlines because it lack good fuel capacity, its short range, & sometime a bit hard to control  in high winds for some pilots. Most passenger airlines phase the airplane out. FedEx have around 57 thats been flying safely all around the world for the last twenty years with only one fatal accident so far.