Windshear is very harmful to the air flight. In the process of take-off and landing, wind shear can be a lot of influence on aircraft airspeed because of the low speed, which makes sudden changes in the position of the spacecraft and height. The result at low altitude is sometimes disastrous. In 1985, 137 people were killed when an airplane at a foss airport in Dallas was destroyed by wind shear. Since then, windshear has been studied as an international topic.
According to Coleman, the principal in Boulder Research Center, after 1985, all aircraft in the United States are installed windshear tester. Canada also installed the corresponding system after 1990. Why is low-altitude windshear so dangerous? This is due to the characteristics of the wind shear itself. In the case of the most harmful microfluidic airflow, it is a comprehensive windshear zone with the main characteristics of vertical wind shear.
Due to the vertical motion in horizontal direction airflow exists large velocity gradient, that vertical movement of the wind speed will be intensified, so strong falling airflow suddenly forms, known as micro-downburst. The strong downdraft exists within a limited area, and after the collision with the ground, it turns parallel to the ground and into the horizontal wind and the wind to spread all direction from the center point. So, in a larger area, it may form the horizontal windshear.
If the plane enters the area during takeoff and landing, it is likely to cause a loss. For example, when the plane is landing, the glide path is just passing through the micro-downburst, and then the plane will suddenly fall off abnormally, deviating from the original glide path, which is likely to be dangerous because of the too low height. When it flies out the micro-downburt, it goes into the wind flow, which suddenly reduces the relative velocity of airflow. We all know that in order not to lose speed, the plane must be greater than the minimal flight speed. Due to during landing he aircraft is in decelerating, so the sudden slowdown is likely to stall the plane into the state of losing speed and the flight altitude is out of control, and in such low altitude and speed, it was impossible for the pilot to give space and time to regain control, resulting in a serious accident.
Severe low-altitude windshear often occurrs in low-altitude, long, narrow strong wind area, giving a great threat to flight safety. This kind of windshear often flow sharply down from the sky, like huge faucet pouring down. When the plane goes into the area, it first encounters strong headwinds, and then encounters fierce sinking airflow, and then it is strong wind. So the plane is like the leaves, which is blown up and down and lose control. Therefore, a serious crash easily happens.
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