There is a point beyond which adding extra engines becomes stupid.I will not contest that.However, the discussion here is about single vs.TWIN.Also, there is a reason why the US Govt picked the EH101 over the S92 as the future Marine One.I am sure that the third engine had something to do with it.
As far as a well maintained single.Define well maintained.I am sure Air Force One is more "well maintained" than the average 747 in any of the airlines.But is that cost effective maintenance?More bang for the buck?
I don't think so.
The ugly truth is that operators will spend the same amount of time effort and money on a single or a twin(proportionately).Yes, when the costs become prohibitive,services will go away.Yes, aviation is all about risk management etc.I am fully cognizant of the risks I take when I strap on the single engine helicopter at 2 in the morning on a pitch dark night.I am just tired of the hypocrisy of operators,engineers and regulators who try to sell this concept to the unwashed masses that there is absolutely no statistics to prove that the twins are no safer than singles.Well. lies,damn lies and statistics.The public is ignorant enough(you won't believe how many times I have been asked if the patient is going to ride on the skids)to swallow anything.But don't try to sell that to me from the comfort of an offfice desk when I am the potential statistic.I will buy economic sense vs. potential loss of a job.What I won't buy is hypocrisy clothed in scientific clothing.
Alt3.