Pucci you are correct.
OP is referring to AA 191 at ORD (engine separation due to faulty MX procedure)
JDiver is referring to the Windsor incident (AA 96 - cargo door opening in flight, damaging control cables)
also infamous is United 232, total hydraulic failure due to #2 engine disk rupture. This design flaw was fixed on the MD-11, and the check valve is referred to as the "Sioux City valve"