What was found
(CAN) DURING TAKEOFF AND CLIMB HELICOPTER STARTED TO YAW CAUSED BY ENGINE SURGING WITH FLUCTUATING NG TORQUE TOT CAUSED BY FAILURE OF AIRFLOW MODULATOR.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
(CAN) DURING TAKEOFF AND CLIMB HELICOPTER STARTED TO YAW CAUSED BY ENGINE SURGING WITH FLUCTUATING NG TORQUE TOT CAUSED BY FAILURE OF AIRFLOW MODULATOR.