What was found
WHILE SECURING THE AIRCRAFT THE MAIN CABIN DOOR BECAME STUCK AT THE CLOSED POSITION TOOK SIGNIFICANT FORCE TO ACTUATE LOCKING HANDLE. WENT TO OPEN THE DOOR AND EXPERIENCED THE SAME SYMPTOMS AND DOOR BECAME STUCK ABOUT 1 INCH OPEN. ARRIVED AT AIRCRAFT AND INSPECTED MAIN COBIN DOOR, FOUND DOOR HINGE TO BE DRY, PERFORMED LUBTICATION OF / DOOR HINGE. PERFORMED OPERATIONAL CHECK OF MAIN CABIN DOOR SEVERAL TIMES WITH NO DEFECTS. MCC ELECTED TO RELEASE. ALL WORK DONE WITH REFERENCE TO AMM-52-10-00