Date: 201306
Local time of day: 1801-2400
Location: DCA.Airport, DC
Flight conditions: VMC
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B DCA
ATC / advisory: Tower DCA
Second aircraft: Helicopter
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Human factors: Distraction; Workload
Anomaly: ATC Issue All Types; Conflict Airborne Conflict
Detector: Automation Air Traffic Control; Automation Aircraft RA; Automation Aircraft TA; Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Procedure; Airspace Structure; Human Factors
Primary problem: Ambiguous

Narrative: It was the end of a long day and the events were happening very quickly during a high workload portion of the flight. As all pilots know; the River Visual is a very demanding approach during the best of circumstances. It is very labor intensive when done at night during periods of high traffic volume. The advertised approach in use at DCA was the LDA 19 with VASI being out of service. During the initial approach; Potomac asked if we would accept the charted River Visual approach (VASI back working) and we did. At approximately the 7 DME point we were in the end process of configuring the airplane for landing and the First Officer was accomplishing the Landing Checklist. The radio chatter was considerable and the Tower at some point advised us of helicopter traffic ahead and to the left (I believe he said 10 to 11 o'clock) and he was going to pass from left to right; below us and he 'HAS US IN SIGHT.' It has to be noted that these traffic calls and helicopters have unfortunately become background noise. There are always numerous military and government helicopters running up and down that river at all times of the day and night. Because of this; what would normally be alarming at any other airport in the country has become commonplace at DCA. The FAA allows these aircraft to operate in this environment and we have no choice; but to accept it and deal with it. Therefore; the helicopters being very close are not out of the norm. As you can imagine; I was concentrating on the approach and doing the required gyrations to stay over the river and not violate the White House prohibited airspace; and to keep the aircraft on the proper vertical profile. The Runway 19 visual was loaded in the FMGC and I was using it as a backup to my eyes. I was 'dead on' the donut and everything looked normal. I was at or very slightly above the recommended altitudes at each DME point. As I was approaching 4 DME; I caught a glimpse of the helicopter out of my left window and he did look higher than I expected to see him. I asked the First Officer to confirm if he was going to cross from north to south. He confirmed; however I directed him to ask the Tower and confirm it with them because it did not look right. The First Officer could not get a word in with the Tower. It was at that point; we got a TCAS 'TRAFFIC' call. Again; this is not out of the 'norm' for DCA. I was getting ready to take possible evasive action because it was getting uncomfortable; all this while trying to fly the demanding profile. Within seconds; we got a TCAS alert; 'MONITOR VERTICAL SPEED.' I complied with the TCAS alert and was thinking of going around but it all happened so very quickly that the point was moot. The helicopter passed 200 FT (MAX) below us. We were at 900 FT; slightly above the path. The Tower never called out the traffic beyond the first notification. The landing was uneventful. Due to the workload; we asked the Ground Controller for the Tower number and I called when I got to my vehicle. I called the Tower and spoke with the Controller in charge. At first it was it was obvious he was somewhat on the defensive and I had to press the point and ask very specific questions about the standard helicopter operations in the area. After some prodding; he admitted that it was a military helicopter flying from/to Ft. Meade and that he was at 700 FT and was 'a little higher than normal.' I asked what altitude was he supposed to be at and he replied; 'three to four hundred feet.' In addition; he did admit that the Tower version of collision avoidance did go to alarm but before they had a chance to react; the event was over. I cannot imagine what business is so pressing that these helicopters are allowed to cross the path of airliners carrying hundreds of people! I do not understand why they are not crossed IN-BETWEEN arrivals. They have at least 4 miles between these arriving aircraft and it seems that would be more prudent.




Synopsis: A320 Captain experiences an airborne conflict with a military helicopter at 900 FT during a River Visual to Runway 19 at DCA. TCAS RA states to monitor vertical speed with the helicopter 200 FT below the A320.