1979 American Airlines Flight 191

1979 American Airlines Flight 191 On May 25, 1979, a McDonnell Douglas DC-10 operated by American Airlines crashed shortly after takeoff from O'Hare International Airport en route to Los Angeles International Airport, killing all aboard and two on the ground. The accident precipitated major inquiries by the National Transportation Safety Board and regulatory action by the Federal Aviation Administration, influenced litigation involving McDonnell Douglas and American Airlines and catalyzed changes affecting McDonnell Douglas DC-10 operations, airworthiness oversight, and airline maintenance practices.

Flight and crash

Flight AA191, a McDonnell Douglas DC-10-10 registered N110AA, taxied from Gate C-34 at O'Hare International Airport and began takeoff run on Runway 32R. During rotation, the left engine pylon and No. 1 engine detached from the left wing, striking the left wing and severing hydraulic and electrical lines, causing roll and yaw. The flight crew attempted to return to Chicago O'Hare International Airport while the aircraft descended into a field near Des Plaines, Illinois, striking terrain and a trailer park; the aircraft broke apart and ignited. Emergency response involved units from the Chicago Fire Department, Cook County Sheriff's Office, and Federal Aviation Administration inspectors; recovery operations included personnel from the National Transportation Safety Board and United Airlines’s operations staff for coordination of manifest and identification.

Investigation

The National Transportation Safety Board launched a comprehensive investigation, assembling wreckage, flight data recorder and cockpit voice recorder transcripts, and witness statements from air traffic control at O'Hare Tower and Approach Control facilities. Investigators examined maintenance records from American Airlines Maintenance Base, pylon overhaul procedures at Northwest Airlines subcontractors, and manufacturer documentation from McDonnell Douglas and General Electric for the CF6 engines. The NTSB convened hearings with testimony from Captain Walter Lux, representatives from Association of Professional Flight Attendants, and engineers from P&W subcontractors; forensic metallurgical analysis was performed by specialists associated with National Bureau of Standards protocols. The resulting NTSB docket included analysis of prior incidents involving DC-10 pylon installations and discrepancies in American Airlines' maintenance alterations.

Causes and contributing factors

The NTSB determined the probable cause to be improper maintenance procedures that led to the failure of the left engine pylon mount assembly due to a fractured pylon fitting. Contributing factors included American Airlines' altered pylon removal and reinstallation technique that bypassed original McDonnell Douglas procedures, fatigue cracking in the pylon, and consequential rupture of hydraulic and electrical systems. Additional factors cited included deficiencies in oversight by the Federal Aviation Administration, design considerations of the McDonnell Douglas DC-10 pylon-wing interface, and communication lapses between airline maintenance management and manufacturer guidance. The investigation also referenced prior service bulletins and Airworthiness Directive history issued by the FAA and correspondence between American Airlines and McDonnell Douglas on maintenance manuals and torque inspection intervals.

Victims and aftermath

All 258 passengers and 13 crew aboard the airliner perished, along with two people on the ground in a nearby residence, producing intense national mourning and extensive legal action. Families of victims filed wrongful-death and product-liability suits naming American Airlines, McDonnell Douglas, and parts suppliers; the litigation involved attorneys from major firms that had previously worked on aviation disasters presented before federal courts in Cook County and the United States District Court for the Northern District of Illinois. The crash influenced memorials in Des Plaines, Illinois and ceremonies attended by representatives from American Airlines and unions such as Air Line Pilots Association. Insurance claims implicated underwriters associated with Lloyd's of London and liability insurers for major aircraft manufacturers.

Safety reforms and legacy

The crash prompted regulatory reforms by the Federal Aviation Administration, additional Airworthiness Directives for the DC-10 fleet, and revisions to maintenance procedures mandated by McDonnell Douglas and adopted by carriers including United Airlines and Delta Air Lines. The accident influenced later certification and design reviews for widebody aircraft such as the Lockheed L‑1011 TriStar and future standards propagated by the International Civil Aviation Organization and European Union Aviation Safety Agency analogs. The event remains a landmark in aviation safety history, cited in aircraft maintenance training, aviation accident investigation curricula at institutions like Embry–Riddle Aeronautical University, and regulatory reform discussions involving the FAA, NTSB, and manufacturer oversight. The DC-10's operational record and subsequent redesigns informed successor program decisions at Boeing and Airbus and reshaped public perception of jetliner safety in the late 20th century.

Category:Aviation accidents and incidents in the United States Category:Airliner accidents and incidents caused by maintenance errors Category:1979 disasters in the United States