As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER PICKING UP A PATIENT FROM AN AIRPORT JUST OUTSIDE OF BLYTHE, CA. ABOUT 8 MINUTES INTO THE FLIGHT THE PILOT FELT A SLIGHT VIBRATION IN THE HELICOPTER FOLLOWED BY A LOW LIGHT AND A LOW NR HORN. THE PILOT LOWERED THE COLLECTIVE AND WENT TO MEC MODE WITH NO RESPONSE IN NR, THE PILOT THEN WENT TO MANUAL (MAN) POSITION AND RAISED THE COLLECTIVE BACK UP, THE NR INCREASED BACK UP BUT SLOWLY DECREASED UNTIL THE LIGHT AND THE LOW NR HORN SOUNDED AGAIN, AT THIS POINT THE PILOT PERFORMED AN AUTO IN THE DESERT.