Originally Posted by
riff_raff
Consider this example. A single engine is apparently acceptable for the F-35B, a couple of which just safely flew across the Atlantic Ocean. Yet the new CH-53K helo is designed to use three engines to make the same flight.
When the established reliability rate of turboshaft engines meets or exceeds that of the rest of the propulsion system which has no operational fault tolerance, such as much of the rotor system and gearbox, what is the justification for not using a single engine?
There isn't one - simplicity is a major benefit and single engines can undoubtedly be safer than twins - It's just human nature - I very much doubt the Pilatus PC12 is any less safe than the King Air and it has many advantages in performance and cost. But I also doubt you would get an oil company flight department to specify it over the twin. Same probably goes for helicopters