As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED AN EXTERNAL GPU DOOR LEFT OPEN AFTER TAKEOFF. CREW ELECTED TO RETURN TO CLT AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED AND FOUND THE GPU DOOR OPEN. MAINTENANCE SECURED DOOR CLOSED AND NO DEFECTS NOTED. AIRCRAFT WAS RELEASED FOR SERVICE.