As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DCA - FL 2286 - ON DESCENT INTO DCA, LEFT LANDING GEAR DOOR SWITCH CAME ON MFDU AFTER THE GEAR WAS LOWERED. CREW HAD THREE GREEN LIGHTS FOR GEAR BUT AS THEY DESCENED BELOW 900 FEET, THE LANDING GEAR AURAL WARNING CAME ON. CREW RECYCLED GEAR AND LIGHT WENT OUT. FLIGHT LANDED IN DCA WITHOUT FURTHER INCIDENT. MX ADJUSTED THE LEFT NR 2 LANDING GEAR DOOR SENSOR PER THE MM. LANDING GEAR FUNCTIONAL CHECK WAS GOOD. (M)