AN MD SUPER 80 ON TURNING ONTO A SNOW COVERED TXWY HAD THE NOSE GEAR SLIDE UP AGAINST A SNOW BANK CAUSING THE NOSE GEAR AND STEERING TILLER TO EXCEED THE TILLER LIMITS STRANDING THE ACFT.

Narrative

THIS WAS A NORMAL APCH AND LNDG WITH AUTOBRAKES ON MEDIUM. RWY 9R WAS ICE AND SNOW COVERED BUT PLOWED; BRAKING ACTION WAS RPTED GOOD FOR FIRST 2/3 OF RWY AND POOR ON LAST 1/3 BY THE ACFT JUST EXITING THE RWY. UPON LNDG AND ROLLOUT; I HAD VERY GOOD DECELERATION TO ALMOST A COMPLETE STOP. TWR ASKED IF WE WERE GOING TO MAKE TXWY F. WE ADVISED THAT WE COULD AND STARTED A L TURN TO THE 90 DEG TXWY. THROUGH ABOUT 45 DEGS OF ACFT TURN; THE NOSEWHEEL TILLER WAS FORCED FURTHER L TO BEYOND FULL DEFLECTION. (I BELIEVE THAT THE PLOWED EDGE OF THE SNOW BUILD-UP CAUSED THE ADDITIONAL DEFLECTION). AT THE POINT WHEN TILLER WENT FULL TURN; THERE WAS A 'POP' AND THE TILLER JAMMED IN THAT POS. I THEN APPLIED BRAKES TO STOP THE ACFT; BUT IT CONTINUED THE DRIFT TOWARDS THE R EDGE OF TXWY F. I THEN WENT INTO REVERSE THRUST TO ABOUT 1.4 EPR. THIS STOPPED THE ACFT FORWARD MOVEMENT. THE NOSEWHEEL STOPPED AT THE DOUBLE YELLOW EDGE TXWY MARKER. (I FOUND THIS OUT WHEN THE GND CREW PLOWED THE 6 INCHES OF SNOW AWAY FOR TUG TRACTION.) WE THEN NOTIFIED THE TWR THAT WE WERE STUCK AND NOT CLR OF THE RWY. THE TWR HAD TO SEND OUT A TUG AND A MECH FOR INSPECTION OF THE NOSEWHEEL STEERING. WHEN THE GND CREW ARRIVED THEY INFORMED US THAT THE ACFT WAS STILL COMPLETELY ON THE TXWY. THEY HOOKED UP THE TOW BAR AND STRAIGHTENED THE NOSEWHEEL; WITH NO DAMAGE NOTED. WE WERE THEN TOWED TO GATE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT WHEN MAINT ARRIVED A TOW BAR WAS ATTACHED AND THE NOSE GEAR CTRED AND THE STEERING RETURNED TO NORMAL OP. THE RPTR SAID THE ACFT DID NOT DEPART THE TXWY AT ANY TIME. THE RPTR SAID AT THE GATE MAINT AGAIN CHKED THE STEERING AND FOUND IT OK FOR SVC.