American Airlines Flight 191

American Airlines Flight 191
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Name	American Airlines Flight 191
Caption	Wreckage at O'Hare International Airport
Date	May 25, 1979
Type	Engine separation leading to loss of control
Site	Des Plaines, Illinois
Aircraft	McDonnell Douglas DC-10
Operator	American Airlines
Tail number	N110AA
Origin	O'Hare International Airport
Destination	Los Angeles International Airport
Passengers	258
Crew	13
Fatalities	273

American Airlines Flight 191 American Airlines Flight 191 was a scheduled American Airlines passenger flight from O'Hare International Airport to Los Angeles International Airport that crashed shortly after takeoff on May 25, 1979, resulting in the deadliest aviation accident in United States history. The accident involved a McDonnell Douglas DC-10 that experienced an uncontained failure and separation of its left engine and pylon assembly, leading to loss of control and impact near Des Plaines, Illinois, killing all aboard and two on the ground. The disaster prompted major investigations by the National Transportation Safety Board, regulatory responses by the Federal Aviation Administration, and industry-wide changes affecting McDonnell Douglas, American Airlines, and General Electric engine operations.

Flight overview

Flight 191 departed O'Hare International Airport's Runway 32R on a routine schedule operated by American Airlines as a long-haul service to Los Angeles International Airport, with a manifest including passengers from varied origins such as New York City, Chicago, and Los Angeles. The flight used a tri-jet McDonnell Douglas DC-10 registered N110AA, powered by three General Electric CF6 turbofan engines similar to installations on other widebody types like the Lockheed L-1011 and the Boeing 747. Commanded by an experienced crew with ties to Airline Pilots Association protocols and subject to Federal Aviation Administration certification, the flight plan conformed to procedures established after incidents like the 1970s aviation safety reforms.

Aircraft and crew

The aircraft, a McDonnell Douglas DC-10-10 delivered to American Airlines in 1972, had been maintained according to manufacturer guidance from McDonnell Douglas and airworthiness directives from the Federal Aviation Administration. The left engine, a General Electric CF6-6, was mounted on a pylon and attached to the left wing via components produced under contract by McDonnell Douglas and inspected under standards influenced by prior incidents such as the 1974 Turkish Airlines crash and regulatory findings from the Civil Aeronautics Board. The flight deck crew included Captain Walter H. May, First Officer James A. Dillard, and Flight Engineer Kenneth G. McAtee, all of whom had histories documented with American Airlines training records and the Air Line Pilots Association, International.

Accident sequence

During the takeoff roll and rotation, the left engine and pylon assembly separated from the wing, striking the left main landing gear and damaging hydraulic and flap systems; debris impact dynamics resembled failures observed in earlier uncontained engine failure events investigated by the National Transportation Safety Board. Instrumentation and crew communications recorded by the Cockpit Voice Recorder and Flight Data Recorder indicated asymmetrical lift and yawing moments similar to aerodynamic disruptions in accidents like Eastern Air Lines Flight 401 and Saudia Flight 163. The flight crew attempted to maintain control and return to O'Hare International Airport, but the airframe entered an unrecoverable roll and descended into a field near Des Plaines, Illinois, colliding with a trailer park and a field, producing catastrophic fragmentation and post-impact fires with casualties mirroring the scale of Tenerife airport disaster proportions within a U.S. context.

Investigation

The National Transportation Safety Board launched a comprehensive investigation involving metallurgical analysis, fatigue testing, and examination of maintenance practices, calling upon experts from General Electric, McDonnell Douglas, American Airlines, and international authorities including representatives from Transportation Safety Board of Canada and British Civil Aviation Authority. Investigators examined maintenance records related to a non-standard procedure used by American Airlines involving removal and reinstallation of the pylon assembly using a forklift—practices previously discussed in airworthiness directive debates and scrutinized in reports from the Federal Aviation Administration. The NTSB's accident docket compared fracture surfaces to previous failures affecting CF6 installations and cross-examined testimony from American Airlines maintenance personnel, manufacturing engineers from McDonnell Douglas, and regulatory staff from the Federal Aviation Administration.

Causes and safety changes

The NTSB attributed the probable cause to the engine and pylon separation due to a maintenance-induced fracture at the pylon rear spar passage, exacerbated by flawed procedures and inadequate oversight, echoing lessons from earlier rulings in aviation safety regulatory history such as reforms following the Evergreen International Airlines and ValuJet Airlines operational reviews. The accident led the Federal Aviation Administration to issue emergency airworthiness directives affecting McDonnell Douglas DC-10 fleets, mandated changes in maintenance procedures for pylon and engine handling across operators including American Airlines and Delta Air Lines, and prompted retrofits and inspections overseen by General Electric and McDonnell Douglas until redesigns and reinforcement programs were implemented.

Aftermath and memorials

In the aftermath, American Airlines revised maintenance manuals and training in coordination with the Air Line Pilots Association, International and the Federal Aviation Administration, while McDonnell Douglas and General Electric faced litigation and reputational consequences in civil suits filed in Cook County, Illinois courts and federal venues. Memorial efforts included commemorations near Des Plaines, Illinois and remembrances coordinated by families and organizations such as Air Disaster Family Assistance groups, with plaques and ceremonies involving local officials from Cook County, Illinois and memorial services held in cities including Chicago and Los Angeles. The disaster remains a central case study in curricula at institutions like the U.S. National Transportation Safety Board Academy and in publications by Flight International and other aviation authorities, influencing modern aircraft maintenance and regulatory policy.

Category:Aviation accidents and incidents in the United States Category:1979 aviation accidents and incidents