Narrative:

About 20 mi north of fat we were asked by fat approach to tell them we we had the airport in sight for a visibility. They were calling 4 mi visibility and haze. We told them we wanted vectors to an ILS. They were landing 29R. We were descended to 3000' and vectored for ILS. We were given a heading of 200 degrees. ATC said there was traffic at 2 O'clock at 3000', a military mlt Y. We picked up traffic at 11 O'clock and asked him. He said traffic was at 2 O'clock and being vectored for visibility approach to 29L. We asked him again and told him we had traffic at 11 O'clock. He reiterated traffic was at 2 O'clock. ATC said we would be vectored through the ILS localizer and reintercept on the other side. The traffic at 11 O'clock was getting closer ATC, then said to turn to 320 degree heading. The 2 aircraft were on converging courses at 3000'. I decided to descend and told the first officer to tell ATC we were leaving 3000'. We passed under the mlt Y by about 500'. We then turned to 320 degree heading and completed the ILS. Then ATC told us he had the aircraft mixed up, but at no time did he try to separate us with altitude. Every vector was turning us into the other aircraft. The last heading would have put our belly to the mlt Y at the same altitude on a converging course, so I elected to descend under the mlt Y. The mlt Y seemed to take evasive action by climbing. Controller should have had altitude sep while conducting parallel approachs in IFR. Also, controller had 2 aircraft mixed up, as he admitted on the radio.

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Original NASA ASRS Text

Title: APCH CTLR VECTORING LGT FOR ILS CREATES A LESS THAN STANDARD SEPARATION INCIDENT WITH AN MLT BY CONFUSING TRAFFIC INFORMATION CALLS.

Narrative: ABOUT 20 MI N OF FAT WE WERE ASKED BY FAT APCH TO TELL THEM WE WE HAD THE ARPT IN SIGHT FOR A VIS. THEY WERE CALLING 4 MI VISIBILITY AND HAZE. WE TOLD THEM WE WANTED VECTORS TO AN ILS. THEY WERE LNDG 29R. WE WERE DSNDED TO 3000' AND VECTORED FOR ILS. WE WERE GIVEN A HDG OF 200 DEGS. ATC SAID THERE WAS TFC AT 2 O'CLOCK AT 3000', A MIL MLT Y. WE PICKED UP TFC AT 11 O'CLOCK AND ASKED HIM. HE SAID TFC WAS AT 2 O'CLOCK AND BEING VECTORED FOR VIS APCH TO 29L. WE ASKED HIM AGAIN AND TOLD HIM WE HAD TFC AT 11 O'CLOCK. HE REITERATED TFC WAS AT 2 O'CLOCK. ATC SAID WE WOULD BE VECTORED THROUGH THE ILS LOC AND REINTERCEPT ON THE OTHER SIDE. THE TFC AT 11 O'CLOCK WAS GETTING CLOSER ATC, THEN SAID TO TURN TO 320 DEG HDG. THE 2 ACFT WERE ON CONVERGING COURSES AT 3000'. I DECIDED TO DSND AND TOLD THE F/O TO TELL ATC WE WERE LEAVING 3000'. WE PASSED UNDER THE MLT Y BY ABOUT 500'. WE THEN TURNED TO 320 DEG HDG AND COMPLETED THE ILS. THEN ATC TOLD US HE HAD THE ACFT MIXED UP, BUT AT NO TIME DID HE TRY TO SEPARATE US WITH ALT. EVERY VECTOR WAS TURNING US INTO THE OTHER ACFT. THE LAST HDG WOULD HAVE PUT OUR BELLY TO THE MLT Y AT THE SAME ALT ON A CONVERGING COURSE, SO I ELECTED TO DSND UNDER THE MLT Y. THE MLT Y SEEMED TO TAKE EVASIVE ACTION BY CLBING. CTLR SHOULD HAVE HAD ALT SEP WHILE CONDUCTING PARALLEL APCHS IN IFR. ALSO, CTLR HAD 2 ACFT MIXED UP, AS HE ADMITTED ON THE RADIO.

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.