Medium large transport being vectored for final approach has TCASII RA.

Attributes
ACN	245729
Time
Date	199307
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dtw
State Reference	MI
Altitude	msl bound lower : 3600 msl bound upper : 4000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dtw
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp pilot : cfi
Experience	flight time last 90 days : 180 flight time total : 13000 flight time type : 2000
ASRS Report	245729
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other

Narrative:

The captain was flying, and we were being radar vectored to the final approach to runway 21R at dtw. We had just reached an assigned heading of 120 degrees for the vector to the final when the controller issued us an immediate left turn to 360 degrees. As we were passing through a heading of about 070 degrees, our TCASII issued a TA followed immediately by an RA. The captain followed the RA and began an immediate descent to 3600 ft. I searched for traffic, picking up the aircraft passing left to right. He appeared to be at approximately 4000 ft, 2 mi away (estimated). Almost simultaneously the controller asked if we had the traffic in sight. We acknowledged that we had him visually. The captain returned to the 4000 ft assigned altitude and approach gave us another vector toward the final for runway 21R. We landed without further event.

Original NASA ASRS Text

Title: MLG BEING VECTORED FOR FINAL APCH HAS TCASII RA.

Narrative: THE CAPT WAS FLYING, AND WE WERE BEING RADAR VECTORED TO THE FINAL APCH TO RWY 21R AT DTW. WE HAD JUST REACHED AN ASSIGNED HDG OF 120 DEGS FOR THE VECTOR TO THE FINAL WHEN THE CTLR ISSUED US AN IMMEDIATE L TURN TO 360 DEGS. AS WE WERE PASSING THROUGH A HDG OF ABOUT 070 DEGS, OUR TCASII ISSUED A TA FOLLOWED IMMEDIATELY BY AN RA. THE CAPT FOLLOWED THE RA AND BEGAN AN IMMEDIATE DSCNT TO 3600 FT. I SEARCHED FOR TFC, PICKING UP THE ACFT PASSING L TO R. HE APPEARED TO BE AT APPROX 4000 FT, 2 MI AWAY (ESTIMATED). ALMOST SIMULTANEOUSLY THE CTLR ASKED IF WE HAD THE TFC IN SIGHT. WE ACKNOWLEDGED THAT WE HAD HIM VISUALLY. THE CAPT RETURNED TO THE 4000 FT ASSIGNED ALT AND APCH GAVE US ANOTHER VECTOR TOWARD THE FINAL FOR RWY 21R. WE LANDED WITHOUT FURTHER EVENT.

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.