2. The deadliest aviation accident in American history, American Airlines Flight 191 crashed after losing an engine during takeoff and being unable to sufficiently reduce its airspeed to prevent the remaining engines from stalling
American Airlines Flight 191, traveling from O’Hare International Airport, in Chicago, Illinois, to Los Angeles International Airport, California, departed on May 25, 1979. Carrying 258 passengers and 13 crew, as the DC-10 reached takeoff speed the primary engine on the left wing ripped away from the aircraft. Unable to abort the takeoff, the pilot attempt an “engine out” controlled ascent and descent. Climbing to approximately 325 feet above the ground and reducing airspeed to 176 miles per hour, the plane stalled mid-effort. Crashing into a field 1.5 kilometers from the runway, all 271 people aboard were killed in addition to two employees at a nearby repair garage.
A subsequent investigation determined that the loss of the engine should not have been enough to cause the pilots to lose control in the manner that they did. Examining the designs of the DC-10, it was discovered that that aircraft did not possess a separate mechanism to lock edge-slats, instead relying on hydraulic pressure. With the loss of the engine, the slat valves were consequently automatically retracted, thus preventing the slowing of airspeed and resulted in Flight 191 traveling too fast for the remaining engines and stalling.