The DC-10 was involved in another deadly crash on May 25 , 1979 , when American Airlines Flight 191 , departing Chicago 's O'Hare Airport , went out of control immediately after takeoff . As the airliner rotated during its takeoff roll , the number one ( left wing ) engine and pylon assembly separated from the wing and swung upward over the top of the wing , severing critical hydraulic lines embedded in the wing 's leading edge , as well as tearing away part of the wing structure . The loss of hydraulic pressure to the leading edge slat actuators caused the slats to retract due to aerodynamic forces , increasing the left wing 's stall speed above the engine failure climb out speed being used by the pilots . With the left wing stalled and further destabilized by asymmetric thrust , the DC-10 rapidly rolled to the left , sharply descended , and crashed , killing all 271 people on board and two individuals on the ground . The loss of Flight 191 remains the deadliest aviation accident in U.S. history . The crash and its aftermath were widely covered by the media and dealt a severe blow to the DC-10 's reputation and sales
American Airlines Flight 191
American Airlines Flight 191
McDonnell Douglas DC-10