An A320 captain reported an evasive action in pct airspace based on a TCASII RA.

Attributes
ACN	588718
Time
Date	200307
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : iad.airport
State Reference	DC
Altitude	msl single value : 8000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pct.tracon
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Route In Use	arrival star : jasen
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : pct.tracon
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	588718
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : airborne critical
Independent Detector	aircraft equipment : tcas other flight crewa
Resolutory Action	flight crew : took evasive action
Supplementary
Problem Areas	Airspace Structure Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Vectored off of jasen arrival by approach. On autoplt, on assigned heading, on assigned altitude. Was given right turn back to STAR (direct manne). Received TCASII RA for threat aircraft at our 10 O'clock position, descending into us. Followed fom guidance for TCASII RA. Had to descend approximately 2000 ft away from assigned altitude. Advised ATC of TCASII RA. Never got visual on threat aircraft (we were too busy). TCASII saved us.

Original NASA ASRS Text

Title: AN A320 CAPT RPTED AN EVASIVE ACTION IN PCT AIRSPACE BASED ON A TCASII RA.

Narrative: VECTORED OFF OF JASEN ARR BY APCH. ON AUTOPLT, ON ASSIGNED HDG, ON ASSIGNED ALT. WAS GIVEN R TURN BACK TO STAR (DIRECT MANNE). RECEIVED TCASII RA FOR THREAT ACFT AT OUR 10 O'CLOCK POS, DSNDING INTO US. FOLLOWED FOM GUIDANCE FOR TCASII RA. HAD TO DSND APPROX 2000 FT AWAY FROM ASSIGNED ALT. ADVISED ATC OF TCASII RA. NEVER GOT VISUAL ON THREAT ACFT (WE WERE TOO BUSY). TCASII SAVED US.

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.