Originally Posted by
Dick Smith
That “ one in a billion” requirement sounds to me that the standard does not call for absolute safety.
No, it is an acknowledgement that - in the real world - "absolute safety" is a myth. Absolute safety simply doesn't exist - particularly in a complex system such as a commercial jetliner.
Originally Posted by
Dick Smith
In in the meantime with the “one in a billion” parameter when is it likely that a twin will end up in the ocean?
Well, at least one 777 has in fact ended up in the ocean - MH370. Of course, based on what's currently known about MH370 the number of engines was immaterial.
As for the rest of your question, all it demonstrates is your lack of understanding of statistics.
BTW, still waiting for you to provide data to back up your claim that quads are safer than twins on long over water routes.