Narrative:

At 13000 ft cruise flight captain and I encountered a stabilizer trim; mach trim; and autoplt pitch trim caution message in our EICAS screen. This lead to hand flying the airplane in a no trim situation. Because extra force was required to fly the airplane we declared an emergency; running the company flight manual instructions on each of the items; briefing our flight attendant and returning to the gate at ZZZ without further incident. Our other MEL's at the time were an ide #1; rtu #2 (communication); navigation light; and dome light. All are acceptable to fly with according to our MEL manual. Upon landing we changed aircraft and departed shortly after in a different aircraft. Later; I did inform my supervisors the items would need to be repaired and cleared before I would feel comfortable flying the aircraft again. It is my understanding that repairs were made that evening. I do not know what lead to this particular system failure but the collection of MEL's may have played a part. It is my belief that items should be cleared/repaired in a timely manner. In the future; if numerous MEL's are encountered on an aircraft at a single time; then I believe I should discuss the situation with my supervisor and if need be; decline the flight.

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Original NASA ASRS Text

Title: A CL-600 FLIGHT CREW EXPERIENCED EICAS MESSAGES STAB TRIM; MACH TRIM; AND AUTOPILOT TRIM. THEY DECLARED AN EMERGENCY AND RETURNED TO THEIR DEPARTURE AIRPORT.

Narrative: AT 13000 FT CRUISE FLT CAPT AND I ENCOUNTERED A STABILIZER TRIM; MACH TRIM; AND AUTOPLT PITCH TRIM CAUTION MESSAGE IN OUR EICAS SCREEN. THIS LEAD TO HAND FLYING THE AIRPLANE IN A NO TRIM SITUATION. BECAUSE EXTRA FORCE WAS REQUIRED TO FLY THE AIRPLANE WE DECLARED AN EMER; RUNNING THE COMPANY FLT MANUAL INSTRUCTIONS ON EACH OF THE ITEMS; BRIEFING OUR FLT ATTENDANT AND RETURNING TO THE GATE AT ZZZ WITHOUT FURTHER INCIDENT. OUR OTHER MEL'S AT THE TIME WERE AN IDE #1; RTU #2 (COM); NAV LIGHT; AND DOME LIGHT. ALL ARE ACCEPTABLE TO FLY WITH ACCORDING TO OUR MEL MANUAL. UPON LNDG WE CHANGED ACFT AND DEPARTED SHORTLY AFTER IN A DIFFERENT ACFT. LATER; I DID INFORM MY SUPVRS THE ITEMS WOULD NEED TO BE REPAIRED AND CLRED BEFORE I WOULD FEEL COMFORTABLE FLYING THE ACFT AGAIN. IT IS MY UNDERSTANDING THAT REPAIRS WERE MADE THAT EVENING. I DO NOT KNOW WHAT LEAD TO THIS PARTICULAR SYSTEM FAILURE BUT THE COLLECTION OF MEL'S MAY HAVE PLAYED A PART. IT IS MY BELIEF THAT ITEMS SHOULD BE CLRED/REPAIRED IN A TIMELY MANNER. IN THE FUTURE; IF NUMEROUS MEL'S ARE ENCOUNTERED ON AN ACFT AT A SINGLE TIME; THEN I BELIEVE I SHOULD DISCUSS THE SITUATION WITH MY SUPVR AND IF NEED BE; DECLINE THE FLT.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.