Accident Details
A commercial pilot with 18,950 flight hours reported that shortly after departure, the "engine blew." The pilot executed a forced landing to a field, and the airplane sustained minor damage.
Engine Examination
Examination of the turbine engine revealed an uncontained separation of the second-stage turbine disk. The failure occurred as a result of low cycle fatigue. No evidence of deep scratches or gouges were observed on the bore surface or on the forward and aft faces of the disk.
Maintenance History
A review of maintenance records showed that the engine had previously been installed on an aircraft registered in a foreign country, and the records were not complete. When the operator purchased the engine, he informed the maintenance facility that the second-stage turbine rotor had been installed on the engine in 1992 with a total of 730 cycles. The maintenance facility then produced a new life-limit card for the second-stage turbine disk. Based on this data, the disk had accrued approximately 1,738 cycles at the time of failure. The rotor had an FAA-approved life limit of 5,400 cycles. However, according to the manufacturer's production records, the second-stage turbine rotor had originally been shipped with zero hours and cycles in a new production engine on January 24, 1973, making the part 33 years old.