What was found
BOS - FLT 6527 - AFTER TAKEOFF, THE LANDING GEAR LEVER WOULD NOT MOVE UP TO THE RETRACT POSITION. CREW ACCOMPLISHED QUICK REFERENCE HANDBOOK PROCEDURES AND RETURNED TO FIELD AT BOS. FLIGHT LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE REMOVED AND REPLACED THE S-106 AIR GROUND SENSE PROXIMITY SENSOR IN ASSOCIATION WITH MM. OPERATIONAL CHECK GOOD. (M)