What was found
WHILE ON FLIGHT TO TEST GEAR FOR PREVIOUS LG DISCREPANCY, SDR COEA2015012101807, THE GEAR RETRACTED WITHOUT A PROBLEM. WHEN THE GEAR WAS PUT DOWN FOR LANDING, THE LT MAIN GEAR INDICATIONS DID NOT INDICATE DOWN & LOCKED. THE CREW ATTEMPTED TO USE THE EMER EXTENSION SYS WITH NO SUCCESS. THE GEAR WAS CYCLED & A SECOND ATTEMPT FAILED. AN EMER WAS DECLARED & A FLY BY THE TOWER WAS PERFORMED TO CHECK IF GEAR WAS DOWN. TOWER REPORTED GEAR APPEARED TO BE DOWN & LOCKED. CREW ATTEMPTED TO PUT GEAR DOWN AGAIN, THIS TIME SUCCESSFULLY. ACFT PERFORMED A NORMAL LANDING. CLEANED & REINSTALLED LT MLG SELF-CLEANING VLV & ADJUSTED THE LT MLG DOWN LOCK PROXIMITY SWITCHES. PERFORMED NUMEROUS GEAR CYCLES & MULTIPLE FREE FALL ASSIST TESTS WITHOUT ANY DISCREPANCIES. OPERATIONS CHECKED GOOD. ACFT RETURNED TO SERVICE.