As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6424 - IAD-BUF - DURING APPROACH THE RT MAIN GEAR WOULD NOT INDICATE SAFE. AIRCRAFT LANDED WITH NO FURTHER INCIDENTS. MAINTNENANCE CLEANED AND LUBED DOWNLOCK MICROSWITCH. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (Z)