Material characteristics of some the LPT blades installed in engine 858322 were consistent with a raw material manufacturing cast that had previously been identified as being susceptible to creep rupture
As a result of this occurrence and at the time of writing this report, the engine manufacturer is revising service bulletin SB 72-1113 to expand the range of blade manufacturing batch numbers that had previously been identified as being predisposed to creep-related failure.
Blades in the batches identified in the service bulletin are to be withdrawn from service as soon as they are next removed from the engine.
Adequately addresses the issue until such point as there are more, unrelated occurrenecs.
