What was found
DURING CRUISE FLIGHT, 1 OR 2 CONTROL ROTOR BLADE ASSEMBLIES SEPARATED FROM ROTOR HEAD. ROTOR CONTROL BLADE ASSY TUBE BROKE OTBD OF 2 BOLTS ATTACHING IT TO CUFF ASSY. THIS CAUSED A VIOLENT VIBRATION AND MINIMMAL CONTROL OF ACFT. LOWERED COLLECTIVE AND TRIED TO MANEUVER HELICOPTER TO A LANDING AREA BETWEEN 2 DRAINAGES. VIBRATION WAS SO VIOLENT THAT WAS UNABLE TO FOCUS ON THE INSTRUMENTS TO VERIFY WHETHER OR NOT WE WERE AUTOROTATING OR TO DETERMINE OUR AIRSPEED. PRIOR TO IMPACT, PULLED FULL COLLECTIVE PITCH. HELICOPTER LANDED ON THE LT SKID AND ROLLED ONTO THE LT SIDE WHERE IT CAME TO REST. LAST INSP WAS COMPLIANCE WITH AD 97-10-16 ON 9/20/08 IAW PARA A ON 9/20/08. 21 HOURS AGO. (K)