There’s one big problem with fast-flying choppers —it’s possible for the backwards rotational velocity of the rotar at certain points to feature backwards speed that effectively makes it “stand still” with respect to the ground below.
This means that lift on one side is strong, while on the other lateral half there is very little lift —this rolls the chopper strongly to the weak side.
To mitigate this the rotar on fast choppers must be spun much faster and the winglets play an important role in maintaining lift, much as we see with the Mi-24, which at certain speeds acts as 50% chopper and 50% airplane.
Are you talking about retreating blade stall?
Any helicopter at cruising airspeed has the problem of `dissymmetry of lift’, where the retreating blade’s lift is subtracted, not added, to the relative wind produced by forward movement.
This problem was solved by Igor Sikorsky in the 1940’s with his rotating swashplate which not only provided control but induced additional pitch as the rotor passed front dead center from advancing to retreating.
I started Army flight school in late 1970 & they taught us all this theory while we were itching to get in the cockpit; the classroom phase was called “nuts & bolts”.
The AH-56A was still a flying prototype. We were shown training films & marveled at its rigid rotor system (unlike semi-rigid & fully articulated rotors) which enabled the Cheyenne to loop the loop (”Wow! Hope I get to do that!”).
Then it was off to Vietnam. Later the word got around that the AH-56 was cancelled because its ability to reach 300 knots with the aid of its pusher propeller was causing the tail rotor to shear off from the sideways strain.
Saw a Cheyenne outside the post museum in Fort Polk in 2001. Still an awesome machine.