What was found
DURING TAXI OUT, THE AIRCRAFT'S MAIN BRAKES LOCKED, CAUSING THE AIRCRAFT TO STOP UN-COMMANDED, AND CAUSING FLIGHT ATTENDANT CREW INJURIES REQUIRING MEDICAL ATTENTION. THE FLIGHT CREW ALSO REPORTED THAT THE AUTO-BRAKE SYSTEM FAILED TO ARM. CORRECTIVE ACTION: MAINTENANCE FOUND THE NO.3 BRAKE ASSEMBLY INBOARD ROTOR FALLING BETWEEN THE STATORS AND LOCKING UP THE NO.3 BRAKE. THE NR 3 BRAKE ASSEMBLY WAS REMOVED AND REPLACED PER THE MD90 AMM. MAINTENANCE ALSO PERFORMED AN ANTI-SKID SYSTEM RETURN-TO-SERVICE TEST WITH NO PRESENT STATUS FAULTS, AND AN AUTO-BRAKE SYSTEM RTS TEST THAT PASSED. THE AUTO-BRAKE SYSTEM ARMED NORMALLY. THE AIRCRAFT WAS RETURNED TO SERVICE. (LP# 9690726)