What was found
FLT JB1148 MCO-BTV ON APPROACH INTO BTV CREW DECLARED EMERGENCY LANDING DUE TO "SLAT FAIL" EICAS MESSAGE, LANDING WAS UNEVENTFUL. BTV MX PERFORMED AMM FIM 27-81-00-810-802-A AND FAULT CODE 27811021ACE AND LEFT WING SLAT DRIVE TORQUE TUBES FOUND JAMMED, ATTEMPTED RESET SLATS STILL LOCKED UP. TROUBLESHOOTING OF SLAT ACTUATORS FOUND LEFT WING ACTUATOR NR 4 TORQUE LIMIT INDICATOR TRIPPED. REMOVED AND REPLACED ACTUATOR NR 4 LEFT IAW AMM 27-81-01 AND PERFORMED MECHANICAL AND ELECTRICAL RIGGING IAW AMM 27-80-00. ALL OPS CHECKS GOOD AND AIRCRAFT RETURNED TO SERVICE.