What was found
CLT FL 319 - AFTER TAKEOFF, THE LANDING GEAR WOULD NOT RETRACT. CREW CYCLED THE GEAR, AND THE GEAR RETRACTED. DURING THE SUBSEQUENT RADIO REPORT TO COMPANY MAINTENANCE, THE AIRCRAFT EXPERIENCED OTHER NON-GEAR RELATED DIFFICULTIES. THE FLIGHT RETURNED TO CLT FOR MAINTENANCE CONSIDERATIONS. MAINTENANCE REPLACED THE 23GA PROXIMITY SENSOR ON THE LEFT MAIN LANDING GEAR.