DFW AIRPORT, TX, USA
N322DL
BOEING 737-232
THE RIGHT ENGINE SEPARATED FROM THE WING AS THE AIRPLANE WAS CLIMBING THROUGH 200 FEET AFTER TAKEOFF. FOLLOWING THE ENGINE SEPARATION, THE CREW CONTINUED THE CLIMB AND WERE VECTORED FOR AN UNEVENTFUL LANDING WITHOUT FURTHER INCIDENT. ENGINE SEPARATION WAS THE RESULT OF THE FAILURE OF THE AFT CONE BOLT AND THE ENGINE SECONDARY SUPPORT ASSEMBLY. THE AFT CONE BOLT FAILED AS RESULT OF A PREEXISTING FATIGUE CRACK, WHILE THE ENGINE SECONDARY SUPPORT ASSEMBLY FAILED AS RESULT OF THE DYNAMIC LOADS THAT EXCEEDED THE DESIGNED CAPACITY OF THE MOUNTING BOLTS. THE TWO FORWARD CONE BOLTS FAILED IN OVERLOAD AS THE ENGINE SWUNG FORWARD DURING THE SEPARATION SEQUENCE. METALLURGICAL TESTING REVEALED THAT THE FATIGUE OF THE AFT CONE BOLT WAS A RESULT OF LUBRICANT INADVERTENTLY INTRODUCED INTO THE CONICAL SURFACE OF THE CONE BOLT.
THE FAILURE OF THE AFT CONE BOLT AS RESULT OF PREEXISTING FATIGUE CRACKING DUE TO IMPROPER MAINTENANCE, AND THE FAILURE OF THE SECONDARY SUPPORT STRUCTURE AS A RESULT OF LOADS THAT EXCEEDED THE CAPACITY OF THE ATTACHING HARDWARE AND THE CRUSHABLE HONEYCOMB CORE.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
