What was found
DURING CLIMB, REPORTED AIRFRAME OSCILLATIONS, SIDE TO SIDE ON T/O FROM 1000 TO 5000 FT & CEASED AFTER THROTTLE RETARDED. CREW RETURNED & LANDED WITHOUT EVENT, ACFT OUT OF SERVICE FOR TROUBLESHOOTING. MX R&R NR 1 ENG MEC, NR 1 ENG FUEL PUMP & YAW DAMPER COUPLER. ALSO INSPECTED LT AND RT ENG MOUNTS, PYLONS, PERFORMED RUDDER FREE PLAY CHECKS, INSPECTED VERTICAL SPAR FITTING ATTACH BOLTS & RUDDER SPAR FLANGE. NO DEFECTS NOTED & OPS CHECKS GOOD. REPLACED RUDDER PCU. OPS CHECKS GOOD.