As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AT CRUISE FLIGHT THE NR 1 ENGINE TORQUE BEGAN TO RAPIDLY RISE WITH INCREASED ENGINE NOISE AND RISING ROTOR RPM. DURING THAT SAME TIME THE AIRCRAFT BEGAN A YAWING MOTION. IMMEDIATELY ADJUSTED POWER AND MANUALLY ADJUSTED THROTTLE NR 1 TO REGAIN CONTROL AND AIRCRAFT WITHIN LIMITS. ADJUSTED THE LANDING DIRECTION INTO THE HEADWIND AND COMPLETED A MINIMUM SPEED RUN ON LANDING. REPLACED NR 1 ENGINE.