Narrative:

Air carrier X had conflict with air carrier Y. This occurred while both aircraft were being vectored for simultaneous ILS approachs. ILS runways 18R/18L in use, we were on a heading 120 degrees for runway 18R ILS (right base). WX condition at 4000 ft MSL were poor. Scattered clouds and a ceiling below us prevented ground contact. While on heading 120 degrees at 4000 ft MSL, crew noticed another company 727 Y on an opposing vector for runway 18L. (Y was approximately 240 degrees). Y was above our altitude, it was obvious he was descending through ours. Approach control pointed out the traffic and I purposely did not say that we had 'traffic in sight.' approach did not appear concerned as we were vectored through our localizer directly towards the other aircraft. Captain initiated a gentle bank north to ensure separation, then began turn to south to intercept localizer, we estimate that Y passed 500 ft vertical and 500 ft horizontal at no time did either aircraft indicate the other was in sight. Upon intercept, I asked controller Y's altitude, we were at 4000 ft the other at 3200 ft. Had this been actual IMC and PF had not take corrective action, a collision may have resulted. In the future we will be much more aggressive with regard to getting the controller to react. Supplemental information from acn 298184: mem approach called company traffic at '11:00/3 mi.' air carrier X level at 4000 ft, IMC conditions. A break in the clouds allowed a visual with company traffic who was tracking the localizer to runway 18L. We were told to expect the ILS to runway 18R our heading was 120 degrees. When I saw the traffic appeared to be descending through our altitude, I made a 10 degree left turn in order to assure some lateral separation. The ATC controller then gave us a heading of 220 degrees to intercept the localizer to runway 18R. We asked for company's altitude and were told he was at 3200 ft MSL. We had been cleared to 3000 ft. The remainder of the flight was uneventful. However, had we continued to remain in IMC conditions, a midair could have occurred.

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Original NASA ASRS Text

Title: ACR X HAD LTSS FROM ACR Y WHILE ON RADAR VECTOR FOR SIMULTANEOUS ILS APCH.

Narrative: ACR X HAD CONFLICT WITH ACR Y. THIS OCCURRED WHILE BOTH ACFT WERE BEING VECTORED FOR SIMULTANEOUS ILS APCHS. ILS RWYS 18R/18L IN USE, WE WERE ON A HDG 120 DEGS FOR RWY 18R ILS (R BASE). WX CONDITION AT 4000 FT MSL WERE POOR. SCATTERED CLOUDS AND A CEILING BELOW US PREVENTED GND CONTACT. WHILE ON HDG 120 DEGS AT 4000 FT MSL, CREW NOTICED ANOTHER COMPANY 727 Y ON AN OPPOSING VECTOR FOR RWY 18L. (Y WAS APPROX 240 DEGS). Y WAS ABOVE OUR ALT, IT WAS OBVIOUS HE WAS DSNDING THROUGH OURS. APCH CTL POINTED OUT THE TFC AND I PURPOSELY DID NOT SAY THAT WE HAD 'TFC IN SIGHT.' APCH DID NOT APPEAR CONCERNED AS WE WERE VECTORED THROUGH OUR LOC DIRECTLY TOWARDS THE OTHER ACFT. CAPT INITIATED A GENTLE BANK N TO ENSURE SEPARATION, THEN BEGAN TURN TO S TO INTERCEPT LOC, WE ESTIMATE THAT Y PASSED 500 FT VERT AND 500 FT HORIZ AT NO TIME DID EITHER ACFT INDICATE THE OTHER WAS IN SIGHT. UPON INTERCEPT, I ASKED CTLR Y'S ALT, WE WERE AT 4000 FT THE OTHER AT 3200 FT. HAD THIS BEEN ACTUAL IMC AND PF HAD NOT TAKE CORRECTIVE ACTION, A COLLISION MAY HAVE RESULTED. IN THE FUTURE WE WILL BE MUCH MORE AGGRESSIVE WITH REGARD TO GETTING THE CTLR TO REACT. SUPPLEMENTAL INFO FROM ACN 298184: MEM APCH CALLED COMPANY TFC AT '11:00/3 MI.' ACR X LEVEL AT 4000 FT, IMC CONDITIONS. A BREAK IN THE CLOUDS ALLOWED A VISUAL WITH COMPANY TFC WHO WAS TRACKING THE LOC TO RWY 18L. WE WERE TOLD TO EXPECT THE ILS TO RWY 18R OUR HDG WAS 120 DEGS. WHEN I SAW THE TFC APPEARED TO BE DSNDING THROUGH OUR ALT, I MADE A 10 DEG L TURN IN ORDER TO ASSURE SOME LATERAL SEPARATION. THE ATC CTLR THEN GAVE US A HDG OF 220 DEGS TO INTERCEPT THE LOC TO RWY 18R. WE ASKED FOR COMPANY'S ALT AND WERE TOLD HE WAS AT 3200 FT MSL. WE HAD BEEN CLRED TO 3000 FT. THE REMAINDER OF THE FLT WAS UNEVENTFUL. HOWEVER, HAD WE CONTINUED TO REMAIN IN IMC CONDITIONS, A MIDAIR COULD HAVE OCCURRED.

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.