As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH LG DOWN & LOCKED, RECEIVED GEAR UNSAFE HORN AS WELL AS BOTH AMBER & RED GEAR UNSAFE LIGHTS, WHICH WERE ILLUMINATED. GEAR UNSAFE LIGHTS CYCLED 6 TIMES FROM AMBER TO RED WHILE PROCEEDING TO GO AROUND IN LEVEL FLIGHT. ALTERNATE EXTENSION PROCEDURES WERE EXECUTED TO ENSURE GEAR WAS DOWN & LOCKED.