What was found
AIRCRAFT WAS NOT GROUNDED: AN EMERGENCY WAS DECLARED INBOUND INTO DCA DUE TO THE FLIGHT CREW REPORTING THAT ENROUTE INTO DCA DURING IMC CONDITIONS AT FL040 NEAR VAAL I INTERSECTION, THE WEATHER RADAR BECAME INTERMITTENT AND THEN UNUSABLE. THE AIRCRAFT LANDED SAFELY AT DCA WITHOUT FURTHER INCIDENT. MAINTENANCE RESET THE WEATHER RADAR CIRCUIT BREAKER AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK OF THE WEATHER RADAR SYSTEM PER AMM 34-41-00 WITH NO ISSUES NOTED.