Close proximity air carrier-medium large transport GA-small aircraft IMC on approach to dca.

Attributes
ACN	192723
Time
Date	199110
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dca
State Reference	DC
Altitude	msl bound lower : 2000 msl bound upper : 2300
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dca
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : commercial pilot : atp pilot : instrument
Experience	flight time last 90 days : 240 flight time total : 20000 flight time type : 1210
ASRS Report	192723
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : nmac non adherence : published procedure non adherence : required legal separation
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	controller : issued new clearance flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	vertical : 300
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was captain on flight arriving dca. RVR was inoperative. Prevailing visibility from dca tower was 1 1/2 mi at time of approach. We had been cleared for ILS to 36. Altitude was approximately 2300 ft MSL on localizer. Everything looked good. Approach issued clearance to the right to 030 degree for vectors. TCASII then gave a TA followed by an RA to climb min 1500 FPM. I executed the climb per TCASII. Climbed to approximately 2800 ft MSL. There TCASII issued 'end of conflict.' advised approach of our actions. They gave a clearance to climb to 3000 ft MSL. And there additional heading south to intercept the localizer and cleared for approach which ended on a go around due to lack of visibility. Revectored for a catii approach and landing. Upon landing, called RAPCON and talked to supervisor, the traffic was IFR, and flew across the localizer path. He said they were 'building a model' of the incident from tapes. Hopefully they will find the cause of the incident. Controller or pilot of light aircraft. I feel that had we not had TCASII, we would be statistics in the morning headlines.

Original NASA ASRS Text

Title: CLOSE PROX ACR-MLG GA-SMA IMC ON APCH TO DCA.

Narrative: I WAS CAPT ON FLT ARRIVING DCA. RVR WAS INOP. PREVAILING VISIBILITY FROM DCA TWR WAS 1 1/2 MI AT TIME OF APCH. WE HAD BEEN CLRED FOR ILS TO 36. ALT WAS APPROX 2300 FT MSL ON LOC. EVERYTHING LOOKED GOOD. APCH ISSUED CLRNC TO THE R TO 030 DEG FOR VECTORS. TCASII THEN GAVE A TA FOLLOWED BY AN RA TO CLB MIN 1500 FPM. I EXECUTED THE CLB PER TCASII. CLBED TO APPROX 2800 FT MSL. THERE TCASII ISSUED 'END OF CONFLICT.' ADVISED APCH OF OUR ACTIONS. THEY GAVE A CLRNC TO CLB TO 3000 FT MSL. AND THERE ADDITIONAL HDG S TO INTERCEPT THE LOC AND CLRED FOR APCH WHICH ENDED ON A GAR DUE TO LACK OF VISIBILITY. REVECTORED FOR A CATII APCH AND LNDG. UPON LNDG, CALLED RAPCON AND TALKED TO SUPVR, THE TFC WAS IFR, AND FLEW ACROSS THE LOC PATH. HE SAID THEY WERE 'BUILDING A MODEL' OF THE INCIDENT FROM TAPES. HOPEFULLY THEY WILL FIND THE CAUSE OF THE INCIDENT. CTLR OR PLT OF LIGHT ACFT. I FEEL THAT HAD WE NOT HAD TCASII, WE WOULD BE STATISTICS IN THE MORNING HEADLINES.

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.