An air carrier medium large transport became alarmed about other traffic on a parallel approach.

Attributes
ACN	252736
Time
Date	199309
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : crl airport : dtw
State Reference	MI
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : dtw tower : lax
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : commercial pilot : instrument
Experience	flight time last 90 days : 180 flight time total : 12000 flight time type : 8500
ASRS Report	252736
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : airborne less severe other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

This flight was on vectors to final ILS 3R to dtw. Parallel approach in progress to 3L also. We were on right base at 4000 ft. There was another aircraft on left base for 3L heading right for us at the same altitude. He showed up on TCASII just outside the 2 mi dots at our altitude. The controller claims he turned us to final. If he did, we didn't hear him and we didn't acknowledge him. He realized the potential conflict about the same time we did, and gave us an immediate turn and lower altitude. At no time did we get an RA on the TCASII, we did get a TA.

Original NASA ASRS Text

Title: AN ACR MLG BECAME ALARMED ABOUT OTHER TFC ON A PARALLEL APCH.

Narrative: THIS FLT WAS ON VECTORS TO FINAL ILS 3R TO DTW. PARALLEL APCH IN PROGRESS TO 3L ALSO. WE WERE ON R BASE AT 4000 FT. THERE WAS ANOTHER ACFT ON L BASE FOR 3L HDG RIGHT FOR US AT THE SAME ALT. HE SHOWED UP ON TCASII JUST OUTSIDE THE 2 MI DOTS AT OUR ALT. THE CTLR CLAIMS HE TURNED US TO FINAL. IF HE DID, WE DIDN'T HEAR HIM AND WE DIDN'T ACKNOWLEDGE HIM. HE REALIZED THE POTENTIAL CONFLICT ABOUT THE SAME TIME WE DID, AND GAVE US AN IMMEDIATE TURN AND LOWER ALT. AT NO TIME DID WE GET AN RA ON THE TCASII, WE DID GET A TA.

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.