A few days ago I said, “I wonder if the failure is to the engine cowling or by-pass ductiong rather than to the engine core.”
I have seen a better photograph in the papers since then showing more detail. In this the rear end of the engine core still shows little structural damage. However the rear of the outer cowling structures that normally enclose this part have disappeared. The remaining forward cowling shows what appears to be smoke or oil stains and its rear edge has an incredibly shredded appearance.
I now think that large parts of the aft core cowl or thrust reverser, if it has one, has been consumed by fire. Except that si from any part that fell to earth. Engineers know that metals can actually burn if immersed in oxygen. Whether that has happened in this incident I do not know. for although the aircraft was travelling at high speed with the chance of ‘fanning’ any flames, it was also at high altitude with relatively little air and thus oxygen to burn.
It seems to me now a more likely possibility that there was an oil leak, perhaps in the bypass duct or intercase, that was ignited by the high temperature part of the engine. This, presumably, was not or could not be extinguished by the activation of on-board fire extinguishers.
The Rolls-Royce development engineers in Derby and in the Singapore Maintenance Base will still be working busily to pore over components; explain and calculate the cause; and the design engineers to design out any likelihood of this incident ever happening again with the Trent 900 engine.
I have to say that my guesses are based upon laughably sketchy evidence. The Rolls-Royce, Quantas and Singapore Airlines engineers will have volumes of data and evidence to think about and act upon. I am afraid, though, that they will not be telling the media much about it any time soon.