As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER T/O,AT APPOX.350FT, NR 1 ENGINE STARTED TO LOOSE TORQUE. IN ABOUT 10SEC. NR 1 PROP STARTED TO FEATHER. DECLARED EMERGENCY AND RTF. LANDING WAS NORMAL. MAINTENANCE REMOVED AND REPLACED NR 1 TORQUE SIGNIAL CONDITINER UNIT,TEST FLIGHT SATISFACTORY.