As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDING GEAR HANDLE WAS JAMMED IN THE UP POSITION AFTER TAKEOFF. FLIGHT RETURNED TO ATL AND LANDED WITHOUT INCIDENT. EMERGENCY GEAR EXTENSION PROCEDURES WERE UTILIZED FOR LANDING. MAINTENANCE INSPECTED COMPLETE GEAR SYSTEM AND PERFORMED GEAR SWING UP TO TEN TIMES. PROBLEM COULD NOT BE DUPLICATED.