As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF THE CREW RETACTED THE LANDING GEAR AND NOTED A UNLOCK LIGHT FOR THE GEAR, THE CREW DECLARED AND EMERGENCY THEN FOLLOWED THE CHECKLIST AND RESOLVED THE PROBLEM. THEY RESENDED THE EMERGENCY AND LANDED SAFELY. MX TROUBLESHOT THE LANDING GEAR SYS AND FOUND THE NLG UPLOCK SWITCH TO BE DEFECTIVE, PN 65-430087. THE SWITCH WAS REPLACE WITH NEW AND FUNTIONAL CHECKS WERE SATISFACTORY.