LTT LANDS WITH THE BRAKES LOCKED AND BLOWS ALL 4 TIRES.

Narrative

I WAS CAPT ON AN LTT. WE WERE ON APCH TO OSU ARPT TO DROP OFF PAX. I CALLED FOR GEAR DOWN AND THE SIC RPTED THAT WE HAD NO GREEN NOSE GEAR DOWN LIGHT. THE SIC TESTED THE LIGHT WITH THE TEST SWITCH AND THE LIGHT ILLUMINATED. THIS INDICATED THAT THE BULB WAS FUNCTIONAL. THERE ARE 3 ADDITIONAL INDICATIONS FOR NOSE GEAR DOWN IN THE LTT. THEY ARE: THE ENG SYNC; NOSEWHEEL STEERING ANNUNCIATORS; AND THE ABSENCE OF A GEAR UNSAFE HORN. THESE 3 INDICATIONS WERE POSITIVE AND I FELT THAT THE NOSE GEAR WAS VERY LIKELY DOWN AND LOCKED. HOWEVER; BECAUSE THE GREEN NOSE GEAR DOWN LIGHT DID TEST FUNCTIONALLY; BUT DID NOT ILLUMINATE WITH THE GEAR DOWN; I ELECTED TO TAKE THE MOST CONSERVATIVE ACTION. THIS WAS CLRLY CONFLICTING INFO. WE EXECUTED A MISSED APCH; ADVISED ATC OF OUR PROB; FUEL AND PAX ABOARD AND REQUESTED MEN AND EQUIP. WITH THE GEAR ALREADY EXTENDED; WE DECIDED TO UTILIZE THE EMER GEAR EXTENSION AND PUT NITROGEN PRESSURE IN THE SYS TO INSURE THAT THE NOSE GEAR WAS STABLE. WE FOLLOWED THE CHKLIST FOR THIS PROC. WE STILL HAD NO GREEN NOSE GEAR DOWN LIGHT. HOWEVER; WE HAD DONE EVERYTHING WE COULD TO INSURE THAT IT WAS DOWN. WE TOUCHED DOWN AND THE ACFT BEGAN SKIDDING. IT WAS APPARENT THAT THE BRAKES WERE LOCKED. WHEN THE ACFT CAME TO REST; I INSTRUCTED THE SIC TO EVAC THE CABIN. WHEN I GOT OUT OF THE ACFT I SAW THAT WE HAD BLOWN ALL 4 MAIN TIRES. SUBSEQUENT MAINT INSPECTION FOUND THE LINES CROSSED FOR EMER BRAKES AND EMER GEAR EXTENSION. BY BLOWING THE GEAR DOWN; WE HAD PUT ALL OF THE NITROGEN PRESSURE TO THE BRAKES. WE ALL WALKED AWAY FROM THIS ONE. I WONDER WHAT MIGHT HAVE HAPPENED IF WE HAD A HYD FAILURE AND THE EMER GEAR EXTENSION FAILED TO EXTEND THE GEAR. WOULD ANY PLT BRAKE? I DOUBT IT.