Lonewolf; A single load failure event (or very low cycle count) is described as being a 'static' failure vs. high cycle count and gradual failure as evidenced by fatigue striations as being a 'fatigue' failure.
JohnDixson: Good question, I was not up to speed on the origin of the flight card and thus the requirement. I was informed that the G's occurred during symmetrical pull up at 1.11 Vne. We would have been governed by Marine Corps or NAVAIR requirements but I am not familiar with the details of those requirements. At the time of the event I was lead design engineer at the flight test site (PAX) maintaining production configuration for the five (5) flight test aircraft (which, except for Z-1, which had the older cockpit dial indicators vs. digital, we later DD-250'ed to the Marin Corps customer as production aircraft). The reason I was called on to inspect the rotor was my previous position as lead structural design engineer on main and tail rotors.