FO OF ACR MLG ACFT LOST DIRECTIONAL CTL OF ACFT DURING LNDG IN SNOW SLUSH ON RWY RESULTING IN DAMAGE TO ACFT AND RWY LIGHTING.

Narrative

FO CONDUCTED FULL ILS APCH TO RWY 12; COUPLED TO AUTOPLT THROUGHOUT APCH. APCH WAS ROUTINE WITH RELATIVELY SMOOTH FLYING CONDITIONS. RPTED WIND WAS 240 AT 7 KTS (STEADY). CAPT CALLED RWY IN SIGHT (12 O'CLOCK) AT 300-400 FT ABOVE TOUCHDOWN ZONE ELEVATION. FO TOOK OVER VISUALLY; DISCONNECTED AUTOPLT; THEN AUTO THROTTLES AND LANDED ACFT MANUALLY. TOUCHDOWN WAS ON CTRLINE; ON SPD AND THE PROPER DISTANCE DOWN RWY. SPOILERS DID NOT DEPLOY AUTOMATICALLY; SO CAPT EXTENDED THEM MANUALLY. AFTER NOSE WAS LOWERED TO RWY; FO APPLIED REVERSE THRUST. ACFT RAPIDLY YAWED 30 DEGS TO THE R. IMMEDIATELY FO CAME OUT OF REVERSE AND APPLIED FORWARD THRUST. CAPT TOOK OVER; APPLIED MORE FORWARD THRUST AND BROUGHT ACFT BACK TO CTRLINE. USING MAX BRAKING; SPOILERS AND REVERSE THRUST; CAPT STOPPED ACFT WITH PLENTY OF RWY STILL REMAINING. TAXIED TO GATE UNEVENTFULLY. UPON REACHING GATE; BOZEMAN GND PERSONNEL RPTED DAMAGE TO 1 REIL AND ONE DISTANCE MARKER (L SIDE OF RWY 12). PRIOR TO LNDG WE RECEIVED RPTS THAT BRAKING ACTION WAS FAIR TO GOOD BY A PREVIOUS LNDG TURBOJET. GND PERSONNEL ALSO RPTED SNOW WAS STARTING TO ACCUMULATE. WE FOUND BRAKING TO BE 'NIL' WITH ABOUT 1-2 INCHES OF SLUSH ON RWY. ALTHOUGH NOT SUBSTANTIATED; NEXT MORNING WE RECEIVED RPTS THAT THE ARR BEFORE US (ABOUT 45 MINS BEFORE) HAD TO WORK HARD TO KEEP THEIR ACFT ON THE RWY; BUT YET RPTED BRAKING FAIR TO GOOD. THAT INFORMATION MAY HAVE POSSIBLY MADE US BETTER PREPARED FOR OUR LNDG ROLLOUT OR MAYBE FROM NOT ATTEMPTING THE LNDG AT ALL.