As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NR 3258 - DCA-BWI - THE NR 4 ENGINE TORQUE ROLLED BACK INFLIGHT AND NG DROPPED TO APPROXIMATELY 40 PERCENT. THE ENGINE WAS SHUTDOWN INFLIGHT IAW STANDARD PROCEDURES. THE AIRCRAFT TURNED BACK AND LANDED IN DCA WITHOUT INCIDENT. REMOVED AND REPLACED THE NR 4 ENGINE FUEL CONTROL UNIT. (M)