Event Description
Shortly after lift-off, the flight crew heard a loud noise, described as similar to but louder than a tire blow-out, as the #1 engine failed. The crew secured the #1 engine, remained in the traffic pattern, and landed on the same runway.
Post-Landing Examination
After landing, an examination revealed that the combustion chamber outer case, part number 616315, had failed from low cycle fatigue. The fatigue had propagated from a bolt hole on the rear flange and progressed forward until it reached a critical length, at which point the remaining fracture was from tensile overload. Nickel-cadmium plating was found in the fatigue-cracked area.
Maintenance History
The case was last replated after it was modified, approximately 5,152 flight hours prior to the incident. The Pratt & Whitney engine repair manual, section 72-42-11, prohibits the nickel-cadmium plating of the front and rear case flange bolt holes.