The attempt to increase the weight of helicopter per payload is a strategy designed to rip off government procurement processes and oil companies - especially in the military where the helicopter effectiveness was severely crippled by carrying spare engines around in Afgan rather than food ammunition etc. ridiculous (massive cost - poor effectiveness)
So it should all have been done in single-engine aircraft in Afghan then????? Just need to find one big and powerful enough to carry what a Chinook does - especially at the high DAs of Afghanistan......... what a load of boll*cks.
Oh and by the way, military aircraft need more redundancy since they get shot at a lot so having a spare engine to get you home rather than crashing in enemy territory is quite a good idea.
if military effectiveness was crippled (which I don't think it was) then lack of performance by old aircraft at high density altitudes and OATs was the limiting factor (Sea King, Lynx and to some extent Merlin).
The military requirement is completely irrelevant to the PC1/2 performance considerations on this thread.