What was found
FOLLOWING O/H AND INSTALLATION OF ENGINE ON AC AN IN-FLIGHT CHECK OF THE NTS SYSTEM WAS PERFORMED IAW MM INSTRUCTIONS. UPON ACTUATION OF THE STOP SWITCH BY THE PILOT FOR THE LT ENGINE THE AC YAWED NOSE LT APPROXIMATELY 20 TO 25 DEGREES. ALSO, THE ENGINE RPM HESITATED TO DECAY FOR 1 TO 2 SECONDS THEN DECAYED NORMALLY TO 35 PERCENT RPM. TROUBLESHOOTING FOLLOWING FLIGHT SHOWED THAT THE (TRIP) PRESSURE OF THE ENGINE WAS HIGHER THAN NORMAL AND THE DECISION WAS MADE TO REPLACE THE TORQUE SENSOR ASSY PN 31017263. A SECOND IN FLIGHT CHECK OF THE NTS SYSTEM WAS PERFORMED WITH THE SAME UNSATISFACTORY RESULTS. FURTHER TROUBLESHOOTING IAW MM. INSTRUCTION WAS CONDUCTED WITH NO DEFECTS NOTED. ENGINE REDUCTION GEARBOX