Narrative:

We were descending into dfw on the acton 1 arrival, ednas transition. The first officer was flying and I was communicating with ATC. Approach control had vectored us to the southeast of acton and held us up to 15000'. Then we were given a turn to 360 degrees to intercept the arrival (aqn 040 degrees right outbnd) and directed to cross hulen intersection (aqn 14 DME) at 11000'. We turned to 360 degrees and initiated descent to 11000'. I told approach control that it would be difficult to make the 11000' crossing restriction having been held to 15000' till that point. The controller then turned us to a 300 degree heading to intercept the arrival in order to give us more airspace in which to make the altitude restriction. As we rolled out on the 300 degree heading, we saw a light aircraft pass beneath us on a near reciprocal heading. Just as we passed over the traffic, the controller advised us of VFR traffic, an small aircraft Y sebnd at 13500'. We were at 14100' descending rapidly to 11000'. While the surface visibility was 10 mi. It appeared hazy at 14000'. Given the maneuvering turns toward the radial, the amount of inside the cockpit attention needed to navigation the arrival and manage altitude and the closure rates and sky conditions, we would have been unable to evade the other aircraft. In this instance, see and avoid was unworkable. Unfortunately, had we collided, we, the crew, would have been held accountable when, in fact, we were doing everything in our professional capabilities to operate safely and responsibly.

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Original NASA ASRS Text

Title: NMAC BETWEEN ACR LGT AND SMA Y NEAR DFW.

Narrative: WE WERE DSNDING INTO DFW ON THE ACTON 1 ARR, EDNAS TRANSITION. THE F/O WAS FLYING AND I WAS COMMUNICATING WITH ATC. APCH CTL HAD VECTORED US TO THE SE OF ACTON AND HELD US UP TO 15000'. THEN WE WERE GIVEN A TURN TO 360 DEGS TO INTERCEPT THE ARR (AQN 040 DEGS R OUTBND) AND DIRECTED TO CROSS HULEN INTXN (AQN 14 DME) AT 11000'. WE TURNED TO 360 DEGS AND INITIATED DSNT TO 11000'. I TOLD APCH CTL THAT IT WOULD BE DIFFICULT TO MAKE THE 11000' XING RESTRICTION HAVING BEEN HELD TO 15000' TILL THAT POINT. THE CTLR THEN TURNED US TO A 300 DEG HDG TO INTERCEPT THE ARR IN ORDER TO GIVE US MORE AIRSPACE IN WHICH TO MAKE THE ALT RESTRICTION. AS WE ROLLED OUT ON THE 300 DEG HDG, WE SAW A LIGHT ACFT PASS BENEATH US ON A NEAR RECIPROCAL HDG. JUST AS WE PASSED OVER THE TFC, THE CTLR ADVISED US OF VFR TFC, AN SMA Y SEBND AT 13500'. WE WERE AT 14100' DSNDING RAPIDLY TO 11000'. WHILE THE SURFACE VISIBILITY WAS 10 MI. IT APPEARED HAZY AT 14000'. GIVEN THE MANEUVERING TURNS TOWARD THE RADIAL, THE AMOUNT OF INSIDE THE COCKPIT ATTN NEEDED TO NAV THE ARR AND MANAGE ALT AND THE CLOSURE RATES AND SKY CONDITIONS, WE WOULD HAVE BEEN UNABLE TO EVADE THE OTHER ACFT. IN THIS INSTANCE, SEE AND AVOID WAS UNWORKABLE. UNFORTUNATELY, HAD WE COLLIDED, WE, THE CREW, WOULD HAVE BEEN HELD ACCOUNTABLE WHEN, IN FACT, WE WERE DOING EVERYTHING IN OUR PROFESSIONAL CAPABILITIES TO OPERATE SAFELY AND RESPONSIBLY.

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.