SMT TAXIING FOR TKOF HAS GND BRAKE FIRE.

Narrative

I RPTED FOR DUTY AT BHM. I WAS ASSIGNED SMT FOR A FLT TO MOBILE DOWNTOWN ARPT. THE ACFT HAD JUST COME OUT OF A 50 HR EVENT. THERE WERE NO UNANSWERED SQUAWKS ON THE ACFT DISCREPANCY RECORD. THE ACFT PASSED MY PREFLT INSPECTION SATISFACTORILY. THE ACFT WAS LOADED WITHIN LIMITATIONS. TAXI CLRNC WAS RECEIVED. TAXI FROM THE RAMP NBOUND ON TXWY G WAS NORMAL. AFTER XING RWY 36 AT MIDFIELD AND TURNING SW ON TXWY A; THE ACFT REQUIRED MORE PWR THAN NORMAL TO TAXI. THERE WERE 2 COMPANY SMT'S BEHIND ME ON THE TXWY. THE ACFT WAS PULLING SLIGHTLY TO THE L AS IF THE L BRAKE WAS DRAGGING. THE PARKING BRAKE HANDLE WOULD NOT GO IN ANY FURTHER THAN IT WAS SO I REQUESTED TO GND CTL TO RETURN TO THE RAMP. I WAS CLRED TO TAXI ON RWY 5. WHILE ON THE RWY; THE GND CTLR ADVISED THAT THERE WERE SPARKS COMING FROM MY ACFT. I COULD SEE THE L MAIN WHEEL AND CONCURRED WHAT HE RPTED. I TOLD HIM I HAD A HOT BRAKE. I TURNED AND CLRED THE RWY. AS I STOPPED THE ACFT; I COULD SEE THE L WHEEL WAS ON FIRE. I SHUT DOWN THE ACFT; GOT OUT AND USED THE ONBOARD FIRE EXTINGUISHER ON THE L WHEEL. I COULD SEE THAT THE R WHEEL WAS ALSO ON FIRE AND I EMPTIED THE FIRE EXTINGUISHER ON THE R WHEEL. THE ARPT FIRE FIGHTERS ARRIVED AND PUT OUT THE FLAMES AS THEY RECURRED ON EACH WHEEL.