The cause of the accident was flight 191 on May 25, 1979. American Airlines McDonnell Douglas DC - 10 - 10 left Chicago O'Hare International Airport (Kilroy, 2002). 191 flight began to take off and shortly after the rotation, the top left engine and tower on the left side was removed from the wing (Kilroy, 2002). The engine and pylon assembly rotates upward and stops in the middle of the runway. Because the parts of the engine and tower were disconnected, most of the cutting edge slats, the surfaces of the hydraulic wings, most of the wires were damaged (National Geographic, 2012).
After taking off at Chicago O'Hare International Airport, American Airlines Flight 191, DC-10 crashed. Previously, on the accelerated runway, the structure of the top engine and tower was separated from the wing while dropped onto the runway while being turned over at the top. After the plane took off, the plane tilted to the left, the aircraft tilted, then bumped into a nearby place. The fundamental cause of the accident was damage due to maintenance. As a result, the assembly procedure of No. 1 engine and tower was separated, and the tower structure was damaged. The installation of the tower was damaged during regular maintenance done 8 weeks ago. American Airlines dismounted the engine tower on the unit when exchanging the engine with a forklift without being approved by aircraft manufacturer McDonnell Douglas. The airline maintenance team changed the recommended engine and pylon exchange procedure to save time and reduce working time.
As it was the fourth fatal accident involving DC - 10 at that time, the 191 flight crash accident caused strong media criticism. In the accident of DC-10 including flight 191, 620 people died. Since the weather is very suitable for flight and there are no signs that a group of birds and other aircraft have caused a collision, the body of engine # 1 is lifted to pay serious attention to the safety of the DC-10 It was done. Another engine is not the only problem as the general person wants to know if a separate engine is the only cause of a crash. As it was supported by the air traffic controller Elllucker's testimony, the investigator wanted to know if fire might have been the cause, and he said that he saw "flash" on the wing Said. This raised people concern that 191 is the result of terrorist attacks. All 60 witnesses who saw the airplane on the runway removed the bombs as they saw the engine # 1 swinging forward and playing on the wings.