Regional Jet 200 ER/LR (CRJ200)
Human-Machine Interface; Workload
Aircraft Equipment Problem Critical
Flight Crew Landed As Precaution; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
At approximately 2;000 FT MSL the Mach trim and Stab trim [warnings illuminated]. We lost both and the trim was stuck at 7.2 units ANU. We tried a few times to re-engage to try and regain trim since it was taking a lot of forward force on the yoke to keep the aircraft from over pitching. We climbed to 13;000 FT and leveled off. I turned on the autopilot to reduce the workload but when we leveled off it was unable to maintain level flight. When I disconnected it to maintain altitude there was a sudden jolt of the aircraft. We then both agreed that an immediate return to [our departure airport] was needed. We ran the QRH and were able to get the Mach and Stab trims to re-engage but the controls still felt very heavy and stiff. Since we felt there was a concern for safety of flight we immediately coordinated with ATC for a return to [our departure airport]. Once we were at the gate in [our departure airport] Maintenance came out to the aircraft. A Mechanic tried pushing and pulling on the yoke and noticed that it took an excessive amount of forward push on the yoke to get it to move and even then it wouldn't go all the way forward. When he pulled on the yoke he could only get it to come about halfway back. He then said that there was something definitely not right with the elevator.
A CRJ flight crew returned to their departure airport shortly after takeoff when all modes of pitch axis control were compromised.