A B737 FLT EXPERIENCE A MALFUNCTIONING RUDDER RESULTING IN AN EMER LNDG.

Narrative

DURING CLBOUT; FO (PF) DISCOVERED RUDDER TRIM WOULD NOT TRIM TO THE L. THE QRH WAS CONSULTED; BUT NO PROC EXISTS FOR A FAILURE OF THIS NATURE. FO TOOK CTL AGAIN. BY THIS TIME; CONSTANT L RUDDER PRESSURE WAS NEEDED. I (CAPT) CALLED DISPATCH AND ASKED FOR A PHONE PATCH WITH MAINT CTL. MAINT CTL SAID WE COULD TRY TO CYCLE TRIM CIRCUIT BREAKER; BUT THAT WOULD BE MY DECISION. (THE QRH SPECIFICALLY PROHIBITS PLTS FROM CYCLING CIRCUIT BREAKER UNLESS AN AUTH TECHNICIAN APPROVES IT; WHICH I THINK IS MAINT! WE DECLINED THIS ADVICE. IT WOULD HAVE BEEN BETTER IF HE WOULD HAVE JUST SAID TO CYCLE THE BREAKER. HE IS THE AUTH PERSON!) AFTER CONSULTING WITH THE FO; DISPATCH AND MAINT CTL; IT WAS DECIDED TO DIVERT TO MCO. (WE WOULD NOT HAVE BEEN ABLE TO HOLD THE RUDDER PRESSURE FOR THE WHOLE FLT; AND IF INADVERTENTLY RELEASED; A POSSIBLE HARD-OVER COULD OCCUR.) MCO HAD LONG RWYS; AND ALSO HAD OTHER ACFT TO TRY TO GET PAX TO EWR. WE DECLARED AN EMER; BRIEFED FLT ATTENDANTS AND HEADED FOR MCO. NORMAL LNDG WAS MADE WITH NO FURTHER INCIDENT. AS OUR LEGS WOULD GET TIRED; WE WOULD HAVE TO SWITCH; AND THIS REQUIRED SOME COORD.