What happened
The aircraft experienced a total loss of power on the number one engine shortly after takeoff. The flight phase was immediately following departure when the failure occurred.
The investigation
Examination of the failed engine revealed substantial damage within the compressor section, extending from stage six rearward. Of the forty stage eight compressor blades, all were forced completely out of their disk dovetail slots.
Of the eighteen remaining blades, seventeen had lost their airfoils due to fractures just above the platform. The final blade was fractured through the root area just below the platform. Metallurgical analysis of this last blade disclosed a diagonal and transverse fracture through the root, progressing in high cycle fatigue from an origin along the edge of the disk.
Findings
The failure mode was identified as mechanical fatigue within the compressor assembly. The specific mechanism involved the propagation of cracks in the blade roots under repeated stress cycles.