What was found
FLIGHT 727, JFK-BQN, ON CLIMBOUT IN STRAIGHT FLIGHT THE A/C HAD TO HOLD 5 DEGREES LEFT BANK TO MAINTAIN HEADING. SAME ON AUTOPILOT OR HAND FLYING. AFTER 20 MINUTES AND SLOWING DOWN AUTOPILOT WAS ABLE TO FLY WINGS LEVEL BY TRIMMING L 3.3 DEGREES. AIRCRAFT RETURN TO JFK, RE-INDEXED ELECTRIC ZERO "0" ON RUDDER TRIM ACTUATOR (10CC) IAW AMM 27-22-51-04. ALL INDICATIONS ARE NOW NORMAL, FUNCTIONAL TEST GOOD. OK TO CONTINUE SERVICE.