SF340 FLT CREW DISCOVERS DURING CLIMB OUT THAT AILERON TRIM OPERATES IN THE OPPOSITE DIRECTION FROM THAT COMMANDED. STANDBY TRIM WAS USED FOR REMAINDER OF FLIGHT.

Narrative

DURING PREFLT OF ACFT X TRIM TEST WAS CONDUCTED IN ACCORDANCE WITH NORMAL PROCS. THE FO WAS THE PF. DURING THE LATE STAGE OF THE CLB; THE FO MADE A COMMENT THAT THE ACFT WAS FLYING 'STRANGE.' WHEN ASKED TO CLARIFY; HE SAID IT SEEMED OUT OF TRIM. AS WE LEVELED AT 11000 FT; THE FO NOTICED THAT THE MAIN ROLL TRIM WAS OPERATING IN AN OPPOSITE DIRECTION COMMANDED. THE CAPT TOOK CTL OF THE ACFT AND VERIFIED THE TRIM MALFUNCTION. AFTER THE MALFUNCTION WAS VERIFIED; THE STANDBY ROLL TRIM WAS USED AND OPERATED NORMALLY. THE MAIN ROLL TRIM WAS THEN SET TO NEUTRAL (ZERO INDICATION); AND THE STANDBY TRIM USED FOR THE REMAINDER OF THE FLT. AFTER THE ACFT WAS PROPERLY TRIMMED; CTL OF THE ACFT WAS RETURNED TO THE FO WHO ACTED AS PF FOR THE REMAINDER OF THE FLT. NO FURTHER ABNORMALITIES WERE NOTED; AND THE FLT LANDED SAFELY. THE TRIM MALFUNCTION WAS DETERMINED INFLT BY THE FO ACTING AS PF. ONCE THE MALFUNCTION WAS IDENTED; THE FAULTY TRIM WAS ISOLATED AND STANDBY TRIM USED FOR THE REMAINDER OF THE FLT. EMER AND ABNORMAL CHKLISTS WERE CONSULTED; AND CIRCUIT BREAKERS FOR AFFECTED TRIM WERE NOTED. FLT THEN CONTINUED AND MADE A NORMAL LNDG AT ZZZ. THE EVENT OCCURRED DUE TO THE MALFUNCTION OF THE MAIN ROLL TRIM. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: MAINTENANCE WAS PERFORMED ON THE AILERON TRIM SYSTEM PRIOR TO THIS DEPARTURE AND AN ERROR WAS MADE IN CONNECTING THE ELECTRICAL CONNECTIONS AND TESTING THE REPAIR.