As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD AND CONTINUOUS HYDRAULIC THUMPING SOUND OCCURRING FROM NOSE GEAR AREA. THUMPING STARTED RIGHT AFTER GEAR RETRACTION AND CONTINUED UNTIL GEAR WAS EXTENDED. THUMPING WAS HEARD AND FELT AT 3-5 SECOND INTERVALS UNTIL THE GEAR WAS EXTENDED SEVERAL MINUTES LATER. DECLARED EMERGENCY, LANDED WITHOUT INCIDENT. R&R UPLOCK PROXIMITY MLG (RH) SENSOR #2.