Air carrier on 4 mi final has TCASII RA. Makes a missed approach.

Attributes
ACN	225752
Time
Date	199211
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dca
State Reference	DC
Altitude	msl bound lower : 600 msl bound upper : 1200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dca tower : lga
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Make Model Name	Helicopter
Flight Phase	descent : approach
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	pilot : flight engineer pilot : cfi pilot : atp pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 1000
ASRS Report	225752
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Miss Distance	vertical : 600
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

I was riding jump seat giving a line check into dca. We were flying the river visual approach to runway 18 at dca. On approach after being cleared to land at 1600-1800 ft MSL, a TCASII advisory appeared at 1200 ft descending. We received an RA requiring 2000 ft climb. The traffic was 600 ft below us and not in sight. The captain followed the RA and flew a missed approach, came back and landed normally. I called the tower after landing. The tower replied that a helicopter was being coordinated with another controller and the helicopter did not have us in sight. (The helicopter was following the river also). Before they could advise us of the traffic, we were going missed approach. In summary, TCASII protected us from poor coordination/handling by dca tower.

Original NASA ASRS Text

Title: ACR ON 4 MI FINAL HAS TCASII RA. MAKES A MISSED APCH.

Narrative: I WAS RIDING JUMP SEAT GIVING A LINE CHK INTO DCA. WE WERE FLYING THE RIVER VISUAL APCH TO RWY 18 AT DCA. ON APCH AFTER BEING CLRED TO LAND AT 1600-1800 FT MSL, A TCASII ADVISORY APPEARED AT 1200 FT DSNDING. WE RECEIVED AN RA REQUIRING 2000 FT CLB. THE TFC WAS 600 FT BELOW US AND NOT IN SIGHT. THE CAPT FOLLOWED THE RA AND FLEW A MISSED APCH, CAME BACK AND LANDED NORMALLY. I CALLED THE TWR AFTER LNDG. THE TWR REPLIED THAT A HELI WAS BEING COORDINATED WITH ANOTHER CTLR AND THE HELI DID NOT HAVE US IN SIGHT. (THE HELI WAS FOLLOWING THE RIVER ALSO). BEFORE THEY COULD ADVISE US OF THE TFC, WE WERE GOING MISSED APCH. IN SUMMARY, TCASII PROTECTED US FROM POOR COORD/HANDLING BY DCA TWR.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.