Mary
Following on from my earlier post: one factor that seems to come up more often than it should is Maintenance Induced Failure. Coincidentally, this report on a CAPS save was released yesterday:
ERA12LA473
An extract from it:
"Examination of the engine revealed that the crankshaft was fractured and that the crankcase exhibited varying degrees of fretting and lock-slot elongation on the main bearing supports, which is consistent with the application of insufficient torque on the cylinder through-bolts by maintenance personnel. New cylinders had been installed on the engine 113 hours before the accident. Because the cylinders were loose, the oil supply at the No. 2 main journal was shut off and the crankshaft broke, which resulted in the subsequent loss of oil pressure to the engine."
The full report is well worth a read both from the point of view of the cause and from the account it gives of the pilot's decision making process.