Two big engines...three or four axis autopilot...full panel of avionics...and NVG's...two pilots...trained, current, and PROFICIENT...not just blessed by management and the legal authorities by means of a company administered checkride.
Do that....and the safety stats will go way up....as will costs...but more people will survive.
Anyone that has flown in the Pacific Northwest, especially when the rains arrive, understand how dangerous it becomes. Single pilot is great until anything...anything throws a stick into the spokes.
I have flown SPIFR in a 412...thus the reason I believe in two closely working pilots in a good crew concept cockpit. You don't see airlines doing it...single pilot that is...and they fly under the very best of conditions at each end of the flight and at altitudes that keep them away from the rocks unlike helicopters.
There is a time and place for single engine aircraft....and if you are hauling paying passengers...that is not it if you are over inhospitable terrain. A forced landing to an already critical patient is usually fatal...that does not seem the right answer to me.