American Airlines flight 191, a McDonnell-Douglas DC-10-10 passenger aircraft crashed into an open field just short of a trailer park about northwest of the departure end of runway 32R at Chicago international airport, Illinois. with 273 fatalities with 258 passengers and 13 crew on is considered to be the deadliest aviation accident to have occurred in the united states. It was noticed that as the aircraft was beginning its take off the left engine fell off, making the plane roll in midair before diving to the ground and bursting into flames. It released a plume of smoke which can be seen miles away.
The National Transportation Safety Board (NTSB) after the investigation determined that the cause of the accident was asymmetrical stall and loss of stall warning and slat disagreement indication systems resulting from maintenance-induced damage leading to No.1 engine separation and pylon assembly during takeoff. From the cockpit voice recorder found after the crash, it was found that the cockpit and the air traffic control lost communication between each other and the pilots were not notified about the lost engine. in addition to engine failure, the hydraulic system also failed but continued to work through motor operators. Improper maintenance procedures were the main cause which led to the failure of the pylon structure. In addition to the cause of the accident was the vulnerability of the design of the pylon attach points to maintenance damage. Insufficient surveillance and inadequate reporting systems by the federal aviation administration to detect and prevent the use of improper maintenance procedures; improper training and communication between the operators all add up to the cause of the accident.
After the post event analysis the preventive measures that could have been taken from preventing such accidnets from repeating are:
- Developing and maintaining a human factors training program particularly for the maintenance operations of aircraft. So that the accidents due to maintenance operations can be prevented and also increase the efficiency of the maintenance operations done on the aircraft.
- Superior notifications and reporting equipment in the aircraft so as to notify the pilots about the situations inside and outside the aircraft.
- system failure testing should be done for each component of the aircraft so that components which depend on each other can be redesigned or alternative measures for the failure of a particular component can be redesigned.
- Increasing the reliability and maintainability of the aircraft equipment which on whole the decreases the maintenance operation and activities.