Relative to
N110AA,
A concise summary of the blame would fall into 3 components:
Flaws in the Design:
The NTSB believed that the design of the DC-10-10 was flawed and lacked sufficient redundancy in the stall warning system. In addition, the leading edge slats did not include a mechanical locking device to prevent slat movement following a failure of the primary controls; FAA certification was based on acceptable flight characteristics with an asymmetrical leading edge slat condition. The pylon attach points were vulnerable to damage during maintenance. Finally, because the structural separation of the engine was considered extremely improbable by McDonnell Douglas, multiple failures resulting from engine separation were not considered.
Flaws in the Maintenance Procedure:
The modified engine maintenance procedure used by American Airlines to service the engines of its DC-10s was not thoroughly examined before it was implemented. Inspection of all DC-10s after the accident revealed similar cracks in nine airplanes. The ECO developed by American Airlines did not emphasize the degree of accuracy required to properly place the forklift and no evaluation of the ability of the maintenance staff to correctly carry out the procedure was ever made. When the maintenance staff had difficultly carrying out the procedure, no attempt was made to notify engineering of the difficulties.
Flaws in the Accident Reporting and Regulatory Mechanism:
Continental Airlines, using a similar maintenance procedure, had developed and corrected similar pylon cracks. Because the airline classified the damage as a maintenance error, neither the airline nor the the manufacturer reported the damage to the FAA. Furthermore, since the cause was determined to be maintenance error, no further investigation was carried out. American Airlines developed its ECO without the benefit of Continental's experience. The NTSB believed that it was the FAA's responsibility to make sure that such information was made available to all interested parties in a timely manner. However, at the time of the accident, FAA regulations concerning maintenance were generally vague, inadequate, and frequently unenforceable.
You can go to this for the complete report. Particularly, scroll down and read section 1.17.1:
https://hfskyway.faa.gov/(A(Lth2wzpE...20Airlines.pdf