As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DTW - FLT 3187 - ON APPROACH, RIGHT GEAR HUNG UP FOR 15 SECONDS UPON GEAR EXTENSION. THE CREW PERFORMED A GO-AROUND AND THE GEAR EXTENDED NORMALLY ON THE SECOND ATTEMPT. MAINTENANCE REPLACED UPLOCK ACTUATOR. SYSTEM OPERATED SATISFACTORILY. (X)