As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE RED NOSE GEAR WARNING LIGHT REMAINED ILLUMINATED WHEN GEAR WAS RETRACTED AFTER TAKEOFF FROM BWI. WHEN THE GEAR WAS EXTENDED FOR RETURN TO BWI THREE GREEN DOWN AND LOCKED LIGHTS WERE INDICATED. THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE NLG DOWNLOCK PROXIMITY SWITCH OUT OF LIMITS IAW MM 32-60-05, FIGURE 204. THE DOWNLOCK SWITCH WAS ADJUSTED IAW MM 32-60-05. NO OTHER DEFECTS WERE NOTED.