RWY EXCURSION AFTER BRAKE FAILURE ON LTT CPR JET.

Narrative

ACFT TOUCHED DOWN APPROX 1500 DOWN 700 FT RWY. CHK PLT ARMED THRUST REVERSERS AND I PULLED UP ON THE PIGGY BACKS. ONLY THE L THRUST REVERSER DEPLOYED. THE CHK PLT STOWED THE R REVERSER LEVER AND YELLED TO GET ON BRAKES. ACFT VEERED TO L AND NOSEWHEEL STEERING WAS ENGAGED. AFTER ACFT RETURNED TO CTRLINE; L REVERSER PWR WAS INCREASED. AS ACFT SLOWED TO 60 KTS; L THRUST REVERSER WAS STOWED. SHORTLY AFTER I YELLED 'I HAVE NO BRAKES.' THE CHK PLT PULLED EMER BRAKE AND SAID PUMP BRAKES. SHORTLY AFTER THAT THE CHK PLT SAID 'I'VE GOT THE AIRPLANE.' THE CTLS WERE RELEASED TO THE CHK PLT. IT WAS APPARENT TO ME THAT WE WERE GOING TO RUN OFF THE END OF THE RWY. I TRIED REVERSE AGAIN AND ONLY THE L REVERSER DEPLOYED AGAIN. I THEN STOWED BOTH REVERSER LEVERS AS WE LEFT THE RWY AT APPROX 40 KTS. THE ACFT LEFT THE RWY; THE FIELD WAS ROUGH AND SOME ROLLING DITCHES. AS THE ACFT WAS COMING TO A STOP; THE CHK PLT SECURED THE ENGS. THE WHEELS AND BRAKES WERE LOOKED AT AFTER EXITING THE ACFT. L OUTBOARD TIRE WAS BLOWN FROM SKIDDING; L BRAKE WAS SMOKING; R BRAKE WAS COLD. SUPPLEMENTAL INFO FROM ACN 217379: OUR LNDG GROSS WT WAS 15000 POUNDS (1000 POUNDS FUEL). THE LNDG DISTANCE FOR A 16000 POUND AIRPLANE (LOWEST GROSS WT ON THE LNDG CHART) WITH A 10 KT TAILWIND IS 2800 FT ANTISKID ON; OR 3500 FT ANTISKID OFF. (THIS INCLUDES A 1000 FT FLOAT FROM THE RWY THRESHOLD TO THE TOUCHDOWN ZONE). AFTER STOPPING; WE FOUND THE L BRAKE HOT AND R BRAKE COLD. THE L OUTBOARD TIRE ON THE L LNDG GEAR WAS FOUND BLOWN DUE TO SKIDDING. R OUTBOARD WAS ALSO FLAT-SPOTTED. OTHER TIRES SHOWED NO SIGN OF WEAR. THIS WAS THE THIRD TIME IN 3 MONTHS THAT A BRAKE MALFUNCTION HAD OCCURRED ON THIS AIRPLANE. NOTE: AIRPLANE WAS COMPLETING HVY MAINT. TWR CLRED US BY PHONE AND HANDHELD RADIO TO ENTER THE RWY OVERRUN WITH A TUG AND CREW OF MEN TO RECOVER THE ACFT. I PRESUMED THIS CLOSED THE RWY. I THEN MADE PHOTOS OF THE TIRE TRACKS FROM THE RWY END TO THE STOPPING POINT. UNFORTUNATELY; THE TWR HAD NOT CLOSED THE RWY. THIS MADE MY PRESENCE ON THE RWY END AND OVERRUN A TECHNICAL RWY INCURSION. A CLASSIC CASE OF MISCOM.