CL65 CREW MADE A VISUAL APCH TO THE WRONG RWY AT DCA.

Narrative

DURING THE FINAL PHASE OF THE RIVER VISUAL TO RWY 19 AT REAGAN WASHINGTON NATIONAL ARPT; WE EXECUTED A GAR AFTER HAVING LINED UP ON THE WRONG RWY (RWY 15). UNEVENTFUL GAR AND SUBSEQUENT LNDG. WE WERE CLRED FOR THE RIVER VISUAL RWY 19 APPROX 10 MI OUT. I HAD FLOWN THIS APCH BEFORE IN DAYLIGHT; BUT NOT AT NIGHT. VISIBILITY WAS EXCELLENT. I HAD RWY 15 IN SIGHT AT ABOUT 8 DME. WHILE CONCENTRATING ON STAYING OVER THE RIVER; I FREQUENTLY LOOKED AWAY FROM THIS ARPT. ABOUT 2-3 DME THE TWR CTLR TOLD US TO 'SQUARE THE BASE' TURN. AT THAT POINT; I REACQUIRED THE ARPT AND WRONGLY IDENTED RWY 15 AS BEING RWY 19; AND BEGAN TO LINE UP ON RWY 15. I SHORTLY REALIZED THAT AN ACFT WAS ON THE RWY; AND THAT I WAS LINED UP ON RWY 15. I INITIATED THE GAR AT THE SAME TIME THE TWR CTLR CALLED FOR A GAR. SUBSEQUENT DEP; RETURN TO ARPT AND LNDG WERE UNREMARKABLE. ON DOWNWIND; I QUESTIONED WHETHER I SHOULD CALL TWR AFTER LNDG. THE CTLR SAID THEY WERE DISCUSSING IT; AND HE WOULD LET ME KNOW. SHORTLY; HE CAME BACK AND TOLD ME TO 'DON'T WORRY ABOUT IT.' THIS IS A FAIRLY DIFFICULT VISUAL APCH TO FLY. EVEN THOUGH I HAD FLOWN IT DURING THE DAY; THE VISUAL CUES ARE DIFFERENT AT NIGHT. RWY 15 WAS VERY PROMINENT DURING THE APCH; AND I APPARENTLY FELL INTO THE TRAP AFTER CONCENTRATING ON STAYING OVER THE RIVER.