As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON APPROACH INTO DCA ON NUMBER ONE NAV, CREW GOT INSTRUMENT APPROACH FLAGS, COMPARITOR FLAGS, AND LOCALIZER/GLIDESCOPE FLAGS. EXECUTED A MISSED APPROACH AND DIVERTED TO IAD. MAINTENANCE PERFORMED OPERATIONAL TESTS OF THE NUMBER 1 AND NUMBER 2 NAV SYSTEM. NO DEFECTS NOTED.