Operating a vehicle outside the defined NATOPS would be grounds for a determination of "pilot error" would it not?
A great comment posted on the article itself:
Descent limits were in place. All rotary winged pilots are trained to observe the 800/40 rule. When ground speed is 40 knots or less rate of descent is not to exceed 800 feet per minute. The NATOPS manual that existed for the Osprey at the time included the 800/40 rule. Brow and Gruber were both trained to observe the 800/40 rule. Gruber himself was an experienced CH-53E pilot. The fact is that if Brow and Gruber had flown any rotary winged platform in the same manner that they flew the Osprey that night, the results would have been the same.
HROD testing of the V-22 showed that the Osprey is less susceptible to entering VRS than any rotary winged platform and when encountered, recovery is achieved much quicker in the Osprey.
http://legacy.vtol.org/pdf/test-60.pdf
"causing one of the rotors to enter VRS and stop rotating,"
Jeremy Herb doesn't know what he's talking about. Due to the high rate of descent one of the proprotors lost lift due to the "dirty air" beneath it; it did not stop rotating, causing the aircraft to roll due to the asymmetric lift.
Walter Jones has been repeatedly rebuked by the Department of the Navy for this crusade of his. He needs to accept that this accident was indeed caused by pilot error and move on. His constituents deserve a Congressman who doesn't spend his career beating a dead horse.
Were John Brow and Brooks Gruber here today they'd admit that they made a number of errors that night in deviating from NATOPS: descending at nearly 3500 feet per minute at ~100 knots, losing situational awareness and violating basic airmanship guidelines. They screwed the pooch and ended up killing 19 Marines in the process. Any other explanation is simply revisionist history.