Lyman,
Your quote:
I still suggest that the slowing of the IPC demonstrates the axial migration of the IShaft aft ward into the "stationery parts of the engine" (AD). Integrity of the shaft is required until disintegration of the I Turbine, IMO.
Again, from the
ATSB Interim Factual Report
The investigation has found that the intermediate pressure (IP) turbine disc failed as a result of an overspeed condition, liberating sections of the IP turbine disc that then penetrated the engine case and wing structure. The disc failure was initiated by a manufacturing defect in an oil feed pipe that resulted in a wall thickness reduction in an area that is machined to receive a coarse filter. That section of the oil feed pipe sustained a fatigue crack during engine operations that lead to an internal engine oil fire that weakened the IP turbine disc. In turn, a circumferential fracture was induced around the disc, allowing it to separate from the IP turbine shaft. The unrestrained disc accelerated to critical burst speed. This lead to the No 2 engine failure and subsequent significant penetration damage to the airframe structure and systems.
Quite honestly, I never saw this report until yesterday. It describes what I have thought and tried to express to you all along. However, you believe differently with no evidence to support your theories. So it remains a standoff, your theories verses factual information and some turbine engine experiences on my part. No sense in continuation of this discussion.
How did one quart of oil incinerate this engine?
Simple, it started a fire in a very sensitive area of the engine that generated heat on top of what was already present, which when combined, exceeded the disc material capability for the temperature experienced.