American Airlines flight 191

American Airlines flight 191 was a flight that took a tragic turn on May 25 of 1979. The flight was being performed in a McDonnell Douglas DC-10 aircraft.

Having taken off from Chicago's O' Hare International Airport, the plane carried 270 passengers and crew for its flight. At 3:02 PM CDT that fateful day, the aircraft began its takeoff down Runway 32R (Right).

Shortly after the takeoff roll began, tower controllers witnessed the number one engine separate from the aircraft and fly up and over the left wing. The aircraft continued in a normal climb momentarily, as fuel and leaking hydraulic fluid spewed in a vapor trail behind the doomed plane. Unknown to the pilots, the engine separation had severed the hydraulic lines that controlled the aircraft's leading-edge wing slats (retractable devices that increase a wing's lift during takeoff and landing). As the hydraulic fluid bled away, the slats retracted on the left wing, creating an asymmetrical lift condition thus allowing the left wing to lose lift while the right wing underwent increasing lift. The aircraft quickly entered an uncontrollable 112-degree bank and pitched nose-down from an altitude of 400 feet slamming into a nearby mobile home park and an open field. All 270 persons on board the aircraft died instantly in a huge ball of flame. In addition, two residents of the mobile home park also perished.

The resulting investigation by the National Transportation Safety Board revealed the probable cause to be attributable to damage to the left wing engine pylon that occurred during an earlier engine change at American's aircraft overhaul facility in Tulsa, Oklahoma. Contributing to the cause were several inoperative key instruments that would have informed the pilots of the slat's asymmetrical condition. However, the NTSB also indicated that given the circumstances of the situation, the pilots were not in any way to blame for the resulting accident.

Many problems with DC-10s were discovered as a cause of the accident, including problems in the wings and engines areas. Since this tragedy happened just after a Western Airlines DC-10 had crashed in Mexico City and six years after a Turkish Airlines DC-10 crashed in Paris, the FAA quickly ordered all DC-10s to be stored until all problems were solved. The result of the problem solving was an arguably more efficient and safe DC-10.

The tragedy of May 25, 1979 in Chicago remains the largest single-aircraft air tragedy in United States history. Ironically, it was this same flight number (191), but operated by a different air carrier (Delta Airlines), that suffered another tragic loss of life at Dallas/Ft. Worth Airport some years later. However in this instance, a Lockheed L-1011 crashed during landing while trying to navigate through a severe thunderstorm. Nor surprisingly, neither company has ever used the 191 flight number again.