What happened
On a flight from Edmonton City Centre Airport to Prince George, a privately operated Piper PA-34-200T Seneca II, registration C-GOLY, experienced a power loss in its right engine while cruising near Hinton, Alberta. After the engine failure, the pilot feathered the right engine and diverted to Edson Airport.
During the approach to Runway 25, the pilot attempted to avoid residential and commercial areas by turning toward the threshold and reducing power on the remaining left engine. This maneuver led to a loss of control, characterized by an erratic flight path and a steep, descending turn. The aircraft struck an airport fence just before the runway threshold. The pilot sustained serious injury, while the three passengers suffered minor injuries.
The investigation
Investigators examined the right engine, a Teledyne Continental LTSIO-360-EB, and discovered a broken crankshaft. Laboratory analysis determined that a fatigue crack had originated subsurface at the fillet radius between the No. 1 rod journal bearing and the No. 2 crankshaft cheek. This crack grew under normal service loads until the crankshaft failed due to overload.
Additionally, the investigation looked into the maintenance history of the component. It was noted that the person responsible for maintenance, who lacked Level 2 non-destructive testing (NDT) certification, had performed the magnetic particle inspection (MPI) for a previous propeller strike without supervision.