McDonnell Douglas Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Declared Emergency
Aircraft; Procedure
On climb out aircraft started rolling right as the speed increased. At 250 knots about 3.5 degrees of left wing down aileron trim was needed for level flight. This aircraft has a history of flight control problems. We felt it was unsafe to continue with the unknown flight control issue. We told center that we needed to return. Approach was notified of fuel and souls on board. Emergency equipment was standing by. We made an uneventful landing and reported the problem. This was a repeat maintenance issue on this airplane. There was a history of flight control problems. When no obvious solution could be found maintenance tried other remedies that did not address the real  issue. This plane should not have been released until the real issue with the flight controls was addressed. When a serious maintenance issue such as flight controls comes up the maintenance department has to make sure the real problem is fixed and not just get the plane released. This could have been a very serious problem with a more serious outcome if this plane kept flying.
During departure aircraft started rolling left as speed increased. Trim was added until rolling stopped. Trim read 3.5 at 250 knots and 15;000 feet. Called center and advised we were returning. ATC vectored us direct.  Configured the aircraft and landed uneventfully. Aircraft control problem is repeat maintenance write up; causing us concern as to the source of problem.
Flight crew experiences a right wing down rolling tendency as the aircraft accelerates to 250 knots after takeoff requiring 3.5 units of left wing down aileron trim. The aircraft had a history of similar flight control issues and the crew elects to return to the departure airport.