As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ROC/EWR - FLT 3633 - MOMENTARY ELEVATOR NOSE DOWN TRIM RUN-AWAY. MAINTENANCE FOUND THE STANDBY PITCH TRIM STICKS IN THE NOSE DOWN POSITION. MAINTENANCE REMOVED AND REPLACED SWITCH 18CG IN REFERENCE TO ATR WIRING MANUAL CH 20. OPERATIONAL CHECKS WERE GOOD. AIRCRAFT WAS RETURNED TO SERVICE. (X)