As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED GEAR DISAGREE RED MESSAGE IN FLIGHT, 6 SECONDS AFTER GEAR HANDLE DEPLOYED. NLG EXTENDED NORMALLY AND MANUAL EXTENSION USED FOR MLG. EMERGENCY DECLARED AND CREW LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOOT, R & R MLG SELECTOR VALVE AND PERFORMED CHECKS IAW AMM. ACFT RELEASED FOR SERVICE.