What was found
DURING APPROACH PUT GEAR HANDLE DOWN & IMMEDIATELY GOT A GEAR DISAGREE L AMBER CAS MESSAGE & A YELLOW X ON LT GEAR INDICATOR. TERMINATED APPROACH & RAN THRU EMER/ABNORMAL CHECKLIST FOR CAS MESSAGE. IAW CHECKLIST, PULLED LANDING GEAR BLOWDOWN HANDLE & GEAR STATUS DIDN`T CHANGE. PULLED THE MAIN GEAR UPLOCK HANDLE & AGAIN, GEAR STATUS DIDN'T CHANGE. AFTER RUNNING CHKLST THRU TO CONCLUSION, DID A LOW PASS & TOWER CONFIRMED GEAR WAS DOWN & NOT IN WHEEL WELL. CAME BACK AROUND & LANDED. WENT FLAPS FULL, THE INDICATOR TURNED TO A RED X. GEAR DID NOT COLLAPSE DURING LANDING OR WHILE BEING TUGGED IN FROM RUNWAY. THE GEAR INDICATIONS NEVER CHANGED. REMOVED AND REPLACED FAILED L MLG UPLOCK SWITCH IAW AMM 32-32-10