Crab
Your assumption that I haven't had my share of dark and stormy nights in inhospitable places is a little harsh. Been more than 500nm from land just for starters.
Yes Shy is right to some extent and Crab's examples are the emotional ones that make people kneejerk to believing that the twin is obvious. BUT the point I am trying to make is deeper than that. Extending to the 'lazy' redundancy concept. The most unreliable part of some helicopters are the duplicated parts and I would prefer to spend the weight/cost/complexity on making a very reliable SIMPLEX system with minimal to zero need for backup.
Safety systems in general really ought to be evaluated with the cost to payload etc taken into account. Otherwise you get the daft situation where 3 flights need to be made in an 'engine failure immune' helicopter against 1 flight in an engine 'exposed' helicopter. [not a complete arguement]. AND duplication can be the answer sometimes, just nothing like as often as people's emotion leads them to believe.
3000shp? do you need 3000hp? 3000x 10 lbs/hp = 30000lbs that's heavy.
How many hp was the Huey (did pretty well, payload and performance wise)
As with the chinook if you need both engines to obtain enough hp then it's not the same thing as redundancy.