Transmission Design
SAS
Regret I can't agree. If any of the three critical gearboxes on the 234 seize then you exit stage left in a hundred bits but if the tail or intermediate gearboxes fail on a single rotor machine you have a fighting chance of making it to the surface. We have seen examples of both of these failure modes in the NS.
As far as the blades hitting the water is concerned a single rotor machine with the pitching centre around the position of the rotor they are a lot less likely to hit the water in equal sea states. The problem for the 234 is that a sudden stop is likely to do for the sync shaft and then it eats itself. A sudden stop on a single rotor is likely to turn it upside down - which is why we have HUET.
G.