As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TRIPLE TACH/ROTOR RPM FAILURE DURING FLIGHT. DURING ROTOR SPEED FAILURE TROUBLESHOOTING, FOUND NR SENSOR BAD DURING FUNCTION TEST OF THE ROTOR SPEED MONITORING SYS AMM 62-41-00, 5-1. REMOVED AND REPLACED SPEED PICK-UP; LIMITED TEST FLIGHT SUCCESSFULLY COMPLETED.