Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
After takeoff with the First Officer (FO) flying it was apparent that the aircraft was out of trim.  The FO said he was having trouble keeping the wings level.  We then received a vector to the north.  We then leveled off and determined the rudder trim was malfunctioning.  It took about 8 units of left trim to maintain level flight.  We [elected to return to the departure airport] and received vectors back.  We determined the aircraft was controllable in the landing configuration at approach speed.  We ran the overweight landing checklist and returned for an uneventful landing flown by the Captain.
I was the Pilot Flying and right after lift off the aircraft wanted to bank hard right. Nothing was making sense at the moment. Both engines were operating normally; and both rudder & ailerons trims were centered but aircraft wanted to roll to the right. Told captain I was having an issue with the aircraft wanting to roll to the right. Added rudder trim to stop the roll and it took 8 units to left to stop the roll. We elected to return for the control problem we were having. The approach and landing were normal with a touchdown weight of 132.0 lbs at 700 VSI. Taxied to the gate and shut her down. Maintenance made the comment that the rudder spiral plate could have been the issue. Will now make sure I spin through more than 5 units of travel in both directions before every gate departure.
A MD83 Flight Crew; with the First Officer flying; reports a strong right rolling tenancy after lift off. Eventually eight units of rudder trim are required for wings level flight and the crew elects to return to the departure airport for an over weight landing.