As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: AUTOTHROTTLE DOES NOT HOLD SELECTED ENGINE THRUST IN N1 MODE. ON CLIMB OUT FROM ONT AUTOTHROTTLE KEPT RETARDING. HAD TO HOLD THROTTLES TO PREVENT FROM ROLLING BACK. DISCONNECT UNTIL CRUISE. THEN OPERATIONS NORMAL. **SUPPLEMENTAL REPORT REQUIRED** (OPEN)