EMER DECLARED WITH PARTIAL LOSS OF ACFT CTL. RETURN LAND.

Narrative

THE FLT BLOCKED OUT ON TIME; XA55L; AND PROCEEDED NORMALLY THROUGH ALL CHKLISTS INCLUDING THE BEFORE TKOF CHKLIST IN WHICH THE FLT CTLS; AILERONS; ELEVATORS AND RUDDER WERE VERIFIED UNLOCKED AND FREE AND THE RED 'CTL' LIGHT WAS EXTINGUISHED. TKOF WAS NORMAL UNTIL ROTATION (V1) WHERE UPON THE PLANE HEADED TO THE L AND R RUDDER PRESSURE WOULD NOT MOVE THE RUDDER. I TOLD THE CAPT THAT WE HAD A PROBLEM AND I SUSPECTED THE RUDDER WAS LOCKED. THE RED 'CTL' LIGHT WAS STILL OUT AND STAYED OUT UNTIL ABOUT 300 FT AGL (20-30 SECONDS). WE WORKED ON THE PROBLEM MOMENTARILY WITHOUT SUCCESS. THE CAPT TOOK CTL OF THE ACFT AND CALLED FOR THE EMER CHKLIST TO SEE IF THERE WAS A PROC FOR THIS SITUATION; BUT THERE WAS NOT. WE NOTIFIED ATC; DECLARED AN EMER; REQUESTED PRIORITY AND EMER EQUIP AND WIDE TURNS BACK TO THE ARPT. THE CAPT LINED UP ON FINAL USING AILERONS AND DIFFERENTIAL PWR. THE FLT ATTENDANT WAS NOTIFIED TO PREPARE THE CABIN FOR AN EMER LNDG. ON FINAL AT ABOUT 200 FT AGL THE RED 'CTL' LIGHT WENT OUT AND RUDDER CTL WAS RESTORED BY ITSELF. THE REST OF THE APCH AND LNDG PROCEEDED WITHOUT FURTHER INCIDENT. LATER THAT DAY; MAINT INFORMED US THAT THE LINEAR ACTUATOR FOR THE RUDDER HAD FAILED AND HAD CAUSED THE RUDDER TO LOCK. MY ONLY SUGGESTION WOULD POSSIBLY BE TO INSPECT THIS AREA AND CHK THE LOCKING MECHANISM AND ITS BACKUP.