What was found
THIS UNIT SUFFERED A MAIN ROTOR BAND FAILURE DURING OPERATION. ONE EACH OF 2 MAIN ROTOR BANDS DETACHED DURING OPERATION CAUSING EXTENSIVE DAMAGE TO THE ROTOR, EXCITER STATOR, AND MAIN STATOR. THIS FAILURE OCCURRED DURING NORMAL OPERATING CONDITIONS. SUBMITTER STATED THIS FACILITY HAS SEEN NUMEROUS FAILURES SIMILAR TO THIS ONE. RECOMMEND REPLACMENT OF STAINLESS BANDS WITH SOLID RINGS OF ALUMINUM. (X)