Radken
"your knowledge and experience about things turbine." I am a civil engineer and that is a good thing, I learned about turbines as a result of this accident. I guess the only witness acceptable to a lawyer here would be TURBINE D.
Some will say ahem..WTF does he know..Haha.. Well I can tell you that the wing structure of the A388 is really kinda strong. The miracle was that the fluids did not burn when the wing was damaged. God was certainly with that flight until the engine was shut down some hours later.
That is not say that the Qantas crew was in anyway lacking, quite the opposite.
As for the fact that it could not be shut down I know that airbus has made some soft wear changes to the control system as Trent 972 has told us. It must be remembered that this aircraft design had a priority of less mass. As an example all of the wiring looms are made from aluminum wire instead of copper.
Wojtek
Are you seeking to teach us about bearings? A grease packed bearing is cooled by energy transfer to mass. An "nm" is a nanometer, and WOW that is tight. Wojtek I are you sure they can get the metal down to that level of accuracy? I honestly cannot see any technology known so far that can do that is steel...but maybe these balls are made from ceramics. Ceramic bearings are the latest trend.
I see what you mean about "overhung" forces yes. Where the bearing is the pivot and load point for a long shaft between several bearings. Well YES...that essentially is the turbine design.
Annex
"Ref. the ongoing oil and bearing discussion. Is there somewhere a list of oils that show the maximum permissable oiltemperature for Jetengine oils ?? Is it correct to say that the Trent 900 runs at borderline oil temperatures ??"
Most of the specs are set by the the U.S. Department of Defence. MIL specs. I believe it is true to say that no other aerospace gas turbine in CIVIL avaition runs at a mean temperature of 180C. Of course as Barit has told us it depends where you measure the temperature and some have suggested that the T900 measures this at the hottest place.
196C maximum is hot. The hotter the oil the more of it escapes into a gasseous state which leads to "coking" but everytime the engineers have checked the T900 no coking has been found.
In my book the high temperature tells a tale of high energy transfers. Certainly if I was the engineer responsible for a T900 I would be taking oil samples everytime the the thing came home, no matter what time of day.
Of course this is another issue: The MBA crowd would say "excuse me!" That is a RR job, or they would say: "Hey, that will take time and cost money...no..that is a RR job...and they have that responsibility". It all depends on your company culture.
The MBAs want the planes in the air making revenue. They really do not see "the big picture". Quite often they need firm advice.