2.3 The Operating Environment and Aircraft Performance

    Wind shear and avoidance of wind shear

    On the afternoon of August 2, 1985, Delta 191 was flying over the sky. When DL191, which had been cruising without any problems, tried to land at Dallas Fort Worth International Airport, something strange began to happen. Just before landing, 800 feet above the ground, the plane suddenly began to accelerate. While pilot was struggling to slow down the, the speed suddenly decreased sharply and the plane fell. The plane, which tried to rise again but lost its lift, eventually crashed. The crash of Delta Airlines Flight 191, which killed a total of 136 people, was caused by Wind shear. Wind shear was a major research topic in the 1980s when it was responsible for several airline crashes, culminating with the 1985 Delta L-1011 tragedy at DFW Airport. Wind shear is now covered heavily in pilot training,. (Tim Vasquez, 2017)

    Wind shear is a change in wind speed and/or direction over a short distance. It can occur either horizontally or vertically and is most often associated with strong temperature inversions or density gradients. Wind shear can occur at high or low altitude. Wind shear refers to a turbulence phenomenon in which the direction or intensity of the wind suddenly changes. It can appear in any direction regardless of vertical or horizontal, and can occur at all altitudes. Wind shear is generated by thunderstorms, fronts, and sea breezes. Wind shears are very dangerous because they cannot predict wind direction and wind speed at all, especially wind shears that meet on the ground are the most dangerous.

    Wind shear, which occurs when an aircraft takes off and lands within a range of 2,000 feet above the ground, poses the greatest risk to the plane. At this altitude, for a short period of time for the aircraft to takes off and lands, the plane flies at a slightly higher speed than the minimum speed that aircraft can fly. However, when you encounter a wind shear at this time, we can lose the lift by the force that shocked enough to breaks down the posture of the aircraft.

    How can I avoid wind shear? First of all, some airports have LLWAS. Therefore, the data should be examined before the flight. In addition, it is possible to check the presence of a wind shear through PIREP. In addition, the presence of wind shear may be determined by checking visually (Blooming dust, rings of dust, and dust devil). If Wind shear is suspected before flight, the best way is to delay takeoff and landing. However, if you know the existence of Wind shear during takeoff, you will have to give up taking off before you reach V1 and stop on the remaining runway if you have enough runway length. however, if you have passed V1, you must maintain the maximum takeoff trust and maintain the appropriate pitch. Humans cannot beat nature. However, if you are fully aware of the dangerous situations created by nature and know how to cope with them, you can avoid danger. The same goes for wind shear.

Vasquez, T. (2017, June). Windshear weather. IFR, 33(6), 20+.  retreived from https://link.gale.com/apps/doc/A495830283/AONE?u=embry&sid=summon&xid=405a43f6