Incident Overview
During the initial climb after takeoff, a fire occurred in the number 2 engine. The flight crew executed an emergency landing, followed by an evacuation. All 369 passengers and 17 crew members evacuated the aircraft through doors 1R, 2R, and 3R.
Evacuation and Slide/Raft Examination
During the evacuation, the slide/rafts at doors 4R and 5R did not operate as intended. Examination of the 4R slide/raft revealed a fractured inflation hose in the area of the regulator end swivel wire groove. Examination of the 5R slide/raft did not disclose any abnormalities that would have precluded normal operation.
Engine Examination
The number 2 engine sustained an under cowl fire in the area of the accessory gearbox. Teardown of the engine revealed that the high-pressure compressor (HPC) forward air seal stack had become disengaged from the hub. The key washer and retaining nut were found disengaged from the threads on the HPC rear shaft. Evidence of light, grooved scoring was observed on the HPC shaft in the area where the retaining nut was found loose. The key washer anti-rotation slots in the HPC hub exhibited contact marks. Dimensional measurements of the HPC rear hub were within specification; however, the HPC hub snap diameter for the front air seal was worn out-of-limits.