What was found
CREW REPORTED GEAR DISAGREE RED WARNING ON SELECTION OF GEAR DOWN. CREW LANDED WITHOUT INCIDENT AFTER GEAR WAS VERIFIED DOWN. MAINTENANCE PERFORMED OPS TEST OF MLG EXTENSION AND RETRACTION. OPS CHECK WAS GOOD AND NO CODES IN HISTORY. MAINTENANCE CLEANED EXCESSIVE SAND AND GREASE FOUND ON MLG SENSORS AND PERFORMED OPS CHECK OF GEAR EXTENSION AND RETRACTION. ACFT RELEASED FOR SERVICE.