As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DCA - FL 826 - WHILE EXTENDING FLAPS BETWEEN 1 AND 5 DEGREE GEAR WARNING HORN SOUNDED. UNABLE TO SILENCE UNTIL GEAR WAS EXTENDED. RECYCLED WITH SAME RESULTS. MAINTENANCE CLEANED 10 DEGREE SWITCH (S138), PERFORMED GROUND TEST PER MM 31-26-00. SYSTEM CHECKS GOOD. (M)