As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT HOVER. DURING INITIAL HOVER PRIOR TO TAKE-OFF THE PILOT NOTICED A HIGH PITCH SCREECHING NOISE THAT WAS EVIDENT ONLY DURING HOVER, AT FLAT PITCH THE NOISE GOES AWAY. MAINTENANCE WAS NOTIFIED AND THE MECHANIC CHANGED THE COMPRESSOR, TURBINE AND GEARBOX ASSEMBLY AND THE AIRCRAFT WAS RETURNED TO SERVICE.(K)