B767 on approach to iad receives TCASII RA, conflicting B757.

Attributes
ACN	574238
Time
Date	200302
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pct.tracon
State Reference	VA
Altitude	msl single value : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pct.tracon
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : pct.tracon
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	574238
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : airborne critical non adherence : published procedure non adherence : required legal separation
Independent Detector	aircraft equipment : tcas other controllera other flight crewa
Resolutory Action	controller : issued alert flight crew : took evasive action
Miss Distance	horizontal : 1500 vertical : 0
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous
Air Traffic Incident	Operational Error

Narrative:

On approach vectors to iad, initially on 195 degree heading at 5000 ft, the controller changed our runway from runway 1L to runway 1R and instructed us to turn left to 120 degree heading. We got a TA at our 2 O'clock position. The controller gave us an immediate turn to 270 degrees for traffic and during that turn we saw a B757 immediately in front coming directly toward us at the same altitude. At the same time we got an RA to climb which we responded to along with a right bank of up to 45 degrees. The WX was clear and the closest approach to the other aircraft estimated 1/4 mi. The time of occurrence was XA20. The voice recorder circuit breaker was pulled.

Original NASA ASRS Text

Title: B767 ON APCH TO IAD RECEIVES TCASII RA, CONFLICTING B757.

Narrative: ON APCH VECTORS TO IAD, INITIALLY ON 195 DEG HDG AT 5000 FT, THE CTLR CHANGED OUR RWY FROM RWY 1L TO RWY 1R AND INSTRUCTED US TO TURN L TO 120 DEG HDG. WE GOT A TA AT OUR 2 O'CLOCK POS. THE CTLR GAVE US AN IMMEDIATE TURN TO 270 DEGS FOR TFC AND DURING THAT TURN WE SAW A B757 IMMEDIATELY IN FRONT COMING DIRECTLY TOWARD US AT THE SAME ALT. AT THE SAME TIME WE GOT AN RA TO CLB WHICH WE RESPONDED TO ALONG WITH A R BANK OF UP TO 45 DEGS. THE WX WAS CLR AND THE CLOSEST APCH TO THE OTHER ACFT ESTIMATED 1/4 MI. THE TIME OF OCCURRENCE WAS XA20. THE VOICE RECORDER CIRCUIT BREAKER WAS PULLED.

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.