Originally Posted by
noneofyourbusiness
And the clutch design was fantastic, well before my time. Comparing it to some other "modern" clutches. Does JSF ring a bell?
I think is more likely to be an oversight in design to let the blades keep rotating on the ground. Not sure you would get much cooling effect with a relatively slow rpm rotation of the blades. The engine would be at ground idle condition, so maybe the exhaust is relatively cool.
If Sikorsky always needed to have the clutch engaged, there would be no reason to have a clutch.
I am guessing whoever designed the clutch wasn't aware you need spring separators to "unstick" the clutch plates. And maybe Sikorsky did not want to add the weight of a brake.
If Sikorsky needed to always keep the clutch engaged, there would be no reason to have a clutch.
“Declutching” down to a slow rpm basically eliminates the blade tip noise from the prop which, like a tail rotor, is far worse than the main rotor noise. Being low to the ground, blade tip erosion from a slow spinning prop is also improved. I think for a combat scout there are operational reasons to prefer a clutchable prop. Reduced power loss from prop profile drag as well. Is all this worth the cost/weight/complexity of a clutchable prop? Completely fair question. Raider included the technology as a demonstrator. I guess it’s possible it is eliminated on Raider-X as not being worth the penalties. We’ll have to see.