Originally Posted by ShyTorque
The Whirlwind, which I flew very early in my career, was reputedly able to enter VRS at a rate of descent not much over 300ft/min. The blades were made from a simple, hollow metal spar, with metal pockets bonded on to form the constant blade profile along its length.
Lower stiffness of the Blades, higher tendency to twist.
The biggest change in helicopter blades design is not the lack of taper but the change in aerofoil sections, moving away from symmetrical to cambered shapes, especially with composite blades where that section can be altered along the length of the blade. Additionally, the lift is varied along the blade using twist rather than taper so the root is at a higher pitch angle than the tip.
There is a difference between high mass flow and high velocity, read about it.
Plus: Composite(plastics) blades have a tendency to higher stiffness, so the AOA in the center of the disc is not the same as with an Steel/Wooden Blade.
Disc load: Same helicopter, MTOW and empty(pilot and fuel are abord...) which gets earlier into VR?
Greetings,