Eric, we know by experience in autorotating helicopters. More pitch implies lower rotor speed.
The question is for Chuck experience. Why? I think that with less rotor speed the flapping action will be bigger. Is this the reason? The rotor flaps so much that you run out of forward cyclic travel?.
Ferràn
Of course; at maximum pitch setting, flapping would have been quite near the teeter stops.
But the stick being up against the forward stop didn’t come as a surprise to us; Bensen wood blades had excess reflex and dependent upon trim tab setting, the stick would often be against the forward stop at ~60 mph.
With correctly designed rotor blades, the pitching moment is zero and flapping angle is directly dependent on airspeed. Not so for rotor blades having built in pitching moments; dependent on torsional stiffness, blades with noseup pitching moments will have a larger flapping angle and will reach flap limits early; blades with nowedown pitching suppress cyclic flapping and may never reach flap stops, in fact, with large negative pitching moments combined with sufficient torsional flexibility, the stick may even move rearward with increasing forward speed.
Ferràn, I drove the length of Spain from Algeciras to the French border in the 1950s along the coastal route. I was a tech rep for the manufacturer of gyroscopic gunsights used on Jet fighters of that era and was transferred from USAF bases in Morocco to the US military advisory group in Denmark.
Spain, with its wood burning locomotives and charcoal burning automobiles was a different place in the 1950s.
