Regional Jet 700 ER/LR (CRJ700)
Flight Crew Commercial
Human-Machine Interface; Workload
Aircraft Equipment Problem Critical
Flight Crew Overcame Equipment Problem; Flight Crew Returned To Departure Airport; General Declared Emergency; General Maintenance Action
Aircraft
On initial climbout at approximately 1;000 FT AGL; as I was completing the after takeoff checklist I noticed a 1/4 left indication on both the rudder and aileron trim. I asked the pilot flying if he had trimmed the aircraft and he hadn't. He then centered the trims and continued the climb but; once centered; the trims deflected left again without command from the pilot flying. The autopilot was engaged and the pilot flying manipulated both trims again. They stabilized momentarily; but as we leveled off at 10;000 to accelerate; I noticed a full right rudder deflection which was not commanded. The autopilot was then disconnected and we continued to climb to 13;000 while the pilot flying tried to get a feel for the aircraft.We then decided to return to our departure airport as controllability had worsened. We were less than 30 miles out and felt that was our best option. Initially; we requested 4L but the condition was worsening so we requested [straight in to] 22R and to have Emergency Equipment standing by.I informed the flight attendants we had a flight control malfunction and would be returning to our departure airport. I gave them the time until touchdown and advised we anticipated no evacuation would be necessary as of that time. Then I performed the landing data assessment and set up the approach and appropriate speeds. An overweight landing was completed at approximately 69;000 LBS with a smooth touchdown and decent rate of less than 200 FPM. Shortly after touchdown we watched the aileron trim go to a full left deflection. We informed ATC that we would no longer need assistance and taxied to the gate with normal operations. Entries were made in the logbook for the overweight landing and trim malfunctions. After discussion on the ground we both felt that the trim indications were not the only issues with this situation.
The First Officer advised he had heard nothing beyond what had occurred during the flight itself.
As we climbed the controls felt light around 1;000 AGL and were not responding as they should. The First Officer asked 'did you do this' pointing at the aileron and rudder trim indices; both trim indications were out of center. I re-centered the trims and continued the climb. This happened a few more times through 10;000 to our assigned altitude of 13;000 and during the climb the aircraft became more difficult to control.[When level] I made shallow turns left and right and the control inputs had very little of their normal feedback.As we made the left turn back to our departure airport the aircraft controls were not responding normally and it was apparent that control of the aircraft was in jeopardy. I was hand flying and the First Officer was operating the radios; I asked him to inform ATC that we needed to land on 22R immediately.As we made our descent to land the First Officer notified the Dispatcher of our return via ACARS. I informed him of the increasing difficulty to control the aircraft. At this point the controls had little or no feed back as I hand flew the ILS. We broke out about 400 FT and made a overweight landing at less than a 200 FPM descent.Maintenance met us at the gate and we discussed the event with them. They mentioned that this aircraft had a Spoiler Stabilizer Control Unit (SSCU) replaced the night before the event and that maybe water got into it or the cannon plug was loose. With the way the controls felt I believe that there was some issue with this repair. The issue was a degradation of control; not a trim runaway or a control and trim malfunction. I believe the SSCU computer was faulty or there was an issue with the repair.
The flight crew of a CRJ-700 encountered uncommanded movement of rudder and aileron trim both with and without the autopilot engaged. The pilot flying stated that there was little or no feedback from manual pilot inputs and felt control of the aircraft was in jeopardy. They declared an emergency and returned to their departure airport.