B747 FLT CREW HAS TXWY EXCURSION AT YMML.

Narrative

AFTER NORMAL LNDG AND ROLLOUT ON RWY 27 AT YMML; TAXIED THE ACFT CLR OF THE RWY ON TXWY M AND THEN ON TO TXWY E; 2 L-HAND TURNS. THE CAPT AND I HAD PREBRIEFED XFER OF STEERING ON TXWY E PRIOR TO XING RWY 34. PRIOR TO XFER; THE ACFT NOSE WAS TRACKING SLIGHTLY L OF CTRLINE. I CORRECTED TO THE R; NOTING A SLIGHT STIFFNESS IN THE TILLER. I INITIALLY ATTRIBUTED THIS TO THE 15+ KT XWIND FROM THE N (L OF THE ACFT ON TXWY E) WE ENCOUNTERED ON LNDG. I INPUT MORE R TILLER TO THE R TO GET THE DESIRED CORRECTION AND RESPONSE. AS THE CORRECTION TOOK EFFECT; AND I APCHED MY LEAD TO CTRLINE; I PUT IN THE REQUIRED TILLER L TO MAINTAIN CTRLINE. THE NOSE DID NOT INITIALLY RESPOND; AND I INCREASED THE INPUT TO GET THE DESIRED RESULT. AT THIS TIME; XFER OF STEERING WAS ACCOMPLISHED WITH THE CAPT; AND THE NOSE WENT SUDDENLY L. THE CAPT THEN ATTEMPTED TO ARREST THE L MOVEMENT. HOWEVER; THE ACFT DEPARTED THE SHOULDER OF THE TXWY. AT THAT TIME; THE CAPT TOLD ME TO ANNOUNCE TO THE FLT ATTENDANTS AND PAX TO REMAIN SEATED WHILE HE SHUT DOWN THE ENGS. TWR WAS INFORMED; AND EMER EQUIP RESPONDED. OPS WAS INFORMED; AND BUS XPORTATION FOR THE PAX ARRANGED.