|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||airport : cos|
|Altitude||msl bound lower : 9000|
msl bound upper : 9000
|Controlling Facilities||tracon : cos|
|Make Model Name||Medium Large Transport|
|Flight Phase||descent : approach|
|Route In Use||enroute : on vectors|
|Make Model Name||Any Unknown or Unlisted Aircraft Manufacturer|
|Flight Phase||climbout : intermediate altitude|
|Affiliation||government : military|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
pilot : military
|Experience||flight time last 90 days : 30|
flight time total : 2000
|Affiliation||government : military|
|Function||flight crew : first officer|
|Qualification||pilot : military|
|Anomaly||conflict : nmac|
|Independent Detector||other flight crewa|
|Resolutory Action||none taken : insufficient time|
|Miss Distance||horizontal : 0|
vertical : 175
|Primary Problem||Flight Crew Human Performance|
On vectors for final ILS 17R. Level at 9000 ft, 260 degree heading, 180 KTS, base leg. Approach control called out traffic at our 12 O'clock position, descending for landing at cos. That traffic was never seen, nor ever became a factor. As we were being vectored across the localizer, I asked approach control if they wanted us to turn to intercept. They gave us a turn to 150 degree heading to intercept the ILS 17R localizer (from the west), cleared for the approach. Immediately after receiving the new vector, the other aircraft passed approximately 150-200 ft over the top of us on a southerly heading. From the time we saw the other aircraft until he passed over us was a matter of a few seconds, with no time to react, or take evasive action. It appeared the other aircraft was in a climb. The WX was VMC, we were on an IFR clearance in VMC, outside the cos arsa. There was no evasive action taken on our part, and apparently not by the other aircraft as well. We were heading to the west, into a low sun over the mountains with the entire crew looking outside for traffic, but mostly from our 12 - 9 O'clock position due to the other traffic that was called out previously. Approach control never advised us of the traffic, and advised us they didn't pick them up until they were approximately 1 NM away. No damage occurred. Do not believe there was a departure or deviation from any rules or regulations on either pilot's part. Lessons learned: 1) can never be too diligent in clearing for other traffic. 2) we departed cos for a radar pattern, and were initially given the frequency for the southern sector (124.0). We were never changed over to the northern sector frequency (118.5) during the approach. Had this been the case, the other traffic may have heard us on the approach and known we were in that area for the approach, and might have seen us sooner, and we might have heard him, and also seen him sooner.
Original NASA ASRS Text
Title: MIL ACFT HAS NMAC ON VECTORS FOR ILS APCH.
Narrative: ON VECTORS FOR FINAL ILS 17R. LEVEL AT 9000 FT, 260 DEG HDG, 180 KTS, BASE LEG. APCH CTL CALLED OUT TFC AT OUR 12 O'CLOCK POS, DSNDING FOR LNDG AT COS. THAT TFC WAS NEVER SEEN, NOR EVER BECAME A FACTOR. AS WE WERE BEING VECTORED ACROSS THE LOC, I ASKED APCH CTL IF THEY WANTED US TO TURN TO INTERCEPT. THEY GAVE US A TURN TO 150 DEG HDG TO INTERCEPT THE ILS 17R LOC (FROM THE W), CLRED FOR THE APCH. IMMEDIATELY AFTER RECEIVING THE NEW VECTOR, THE OTHER ACFT PASSED APPROX 150-200 FT OVER THE TOP OF US ON A SOUTHERLY HDG. FROM THE TIME WE SAW THE OTHER ACFT UNTIL HE PASSED OVER US WAS A MATTER OF A FEW SECONDS, WITH NO TIME TO REACT, OR TAKE EVASIVE ACTION. IT APPEARED THE OTHER ACFT WAS IN A CLB. THE WX WAS VMC, WE WERE ON AN IFR CLRNC IN VMC, OUTSIDE THE COS ARSA. THERE WAS NO EVASIVE ACTION TAKEN ON OUR PART, AND APPARENTLY NOT BY THE OTHER ACFT AS WELL. WE WERE HDG TO THE W, INTO A LOW SUN OVER THE MOUNTAINS WITH THE ENTIRE CREW LOOKING OUTSIDE FOR TFC, BUT MOSTLY FROM OUR 12 - 9 O'CLOCK POS DUE TO THE OTHER TFC THAT WAS CALLED OUT PREVIOUSLY. APCH CTL NEVER ADVISED US OF THE TFC, AND ADVISED US THEY DIDN'T PICK THEM UP UNTIL THEY WERE APPROX 1 NM AWAY. NO DAMAGE OCCURRED. DO NOT BELIEVE THERE WAS A DEP OR DEV FROM ANY RULES OR REGS ON EITHER PLT'S PART. LESSONS LEARNED: 1) CAN NEVER BE TOO DILIGENT IN CLRING FOR OTHER TFC. 2) WE DEPARTED COS FOR A RADAR PATTERN, AND WERE INITIALLY GIVEN THE FREQ FOR THE SOUTHERN SECTOR (124.0). WE WERE NEVER CHANGED OVER TO THE NORTHERN SECTOR FREQ (118.5) DURING THE APCH. HAD THIS BEEN THE CASE, THE OTHER TFC MAY HAVE HEARD US ON THE APCH AND KNOWN WE WERE IN THAT AREA FOR THE APCH, AND MIGHT HAVE SEEN US SOONER, AND WE MIGHT HAVE HEARD HIM, AND ALSO SEEN HIM SOONER.
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.