EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Confusion; Distraction; Troubleshooting
Aircraft Equipment Problem Critical
Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action; General Maintenance Action
Human Factors; Aircraft
While climbing out of Saint Louis I added some aileron trim to compensate for pressure I felt. The aircraft seemed to climb and turn like it should so I then engaged the autopilot and continued to climb. Somewhere around FL250 to FL270 the aircraft began a turn to the right off course. We checked to see if we had bumped the autopilot turn knob; trying to figure out why it turned. I turned the autopilot off and trimmed the airplane for level climb and hand flew for a while then engaged autopilot to see if it would be okay. The autopilot and airplane flew fine until we started descent. Around FL290 in descent we had multiple call out messages that were not consistent with where we were. We received 'don't sink'; 'pull up'; 'terrain' and 'bank angle' with little or no bank. When we leveled the oral messages would stop. We consulted the QRH and tried to figure out what applied to what was going on. We even pulled MEL to try and find something. We then descended again and got some of the same messages that we had received earlier. I am not sure at what altitude but at some point I decided to turn the autopilot off and hand fly to our destination. I believe the messages stopped and did not come back. On approach; as we slowed I noticed that I was having to use [increasing] left aileron [input]. On final with Flaps 45 I was between three quarters to full left aileron to left to hold straight and level. This also caught us off guard because there was a crosswind from the right. We touched down smoothly and when we arrived at the gate we moved the yoke and checked the ailerons outside and the trim. I called Maintenance and told them what was going on and wrote up the flight controls as sticking. They then decided to swap aircraft. As I left I passed the Captain that was supposed to take the aircraft from me and told him what happened. He said he thought we should put a separate discrepancy in logbook describing the unwanted turn while autopilot was engaged. He then called that write up in to Maintenance Control. Once I was headed to the hotel I called the Chief Pilot and told him what had happened. [Later] I got a call from the chief pilot and we discussed what had happened.
An EMB-145 flight crew was flummoxed by inappropriate EGPWS call-outs while at high flight levels and a tendency for the aircraft to initiate uncommanded turns to the right.  Upon landing nearly full left aileron was required to maintain wings level on approach; despite a crosswind from the right.