As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA - AIRCRAFT EXPERIENCED LOUD BANGING WHEN NOSE LANDING GEAR RETRACTED. EMERGENCY DECLARED, RETURNED MIA WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED RIGHT NOSE GEAR DOOR ACTUATOR CYLINDER. SYSTEM GROUND CHECK NORMAL OPERATION.