What was found
CLT-MDT - FLT 910 - AFTER TAKEOFF, WHEN THE GEAR HANDLE WAS PLACED IN THE UP POSITION, THE RIGHT MAIN GEAR UNSAFE LIGHT REMAINED ILLUMINATED. WHEN PLACING THE GEAR HANDLE DOWN, THE UNSAFE LIGHT EXTINGUISHED AND 3 GREEN LIGHTS ILLUMINATED. MAINTENANCE FOUND THE GEARS IN NEED OF LUBRICATION. LUBRICATED AND CYCLED THE LANDING GEARS. THE RIGHT MAIN GEAR UP PROX. SENSOR WAS REPLACED PRECAUTIONARY. (M)