Narrative:

On a scheduled flight into iad, we were given a clearance to cross 'robrt' at 9000 ft. Began a 750 FPM descent and shortly thereafter, contacted dulles approach. Approaching 10000 ft, TCASII issued a TA. Target was displayed 5-10 mi behind us, approximately 2000 ft higher, same direction of flight, and in a high rate of descent. Before we had time to query ATC about the traffic, a 'climb, crossing climb' RA was issued. I disengaged the autoplt and began a 1700 FPM climb (we were approximately 9600 ft at the time of the RA). The captain (who was not flying) informed approach that we were in a TCASII commanded climb. The controller replied that the traffic was leveling at 10000 ft and if we did anything we should descend. The captain then said to me that maybe I should stop the climb. I told him that maneuvering in opposition to TCASII might cause a midair regardless of ATC instructions. At about 10300 ft, the captain looked out his side window and exclaimed 'whoa!' I looked and saw the traffic, an air carrier widebody transport, pass us at very close range. The air carrier jet then told approach that TCASII was telling them to descend. If we had stopped our climb when ATC instructed, we may have collided. I also feel that air carrier did not comply with its own TCASII at first, because we passed much too close (they were probably at their assigned altitude of 10000 ft). It is my understanding that some pilots routinely disregard TCASII RA's. To prevent these sits from recurring, controllers and pilots should be educated more about the dynamics of TCASII encounters. Controllers need to stay out of the encounter once an RA (or RA's) is issued, and pilots must strictly comply with the RA. The reason I was sure about what to do was that I had just read about this type of situation in a NASA callback.

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Original NASA ASRS Text

Title: NMAC RESULTS WHEN TCASII RA IS NOT OBEYED.

Narrative: ON A SCHEDULED FLT INTO IAD, WE WERE GIVEN A CLRNC TO CROSS 'ROBRT' AT 9000 FT. BEGAN A 750 FPM DSCNT AND SHORTLY THEREAFTER, CONTACTED DULLES APCH. APCHING 10000 FT, TCASII ISSUED A TA. TARGET WAS DISPLAYED 5-10 MI BEHIND US, APPROX 2000 FT HIGHER, SAME DIRECTION OF FLT, AND IN A HIGH RATE OF DSCNT. BEFORE WE HAD TIME TO QUERY ATC ABOUT THE TFC, A 'CLB, XING CLB' RA WAS ISSUED. I DISENGAGED THE AUTOPLT AND BEGAN A 1700 FPM CLB (WE WERE APPROX 9600 FT AT THE TIME OF THE RA). THE CAPT (WHO WAS NOT FLYING) INFORMED APCH THAT WE WERE IN A TCASII COMMANDED CLB. THE CTLR REPLIED THAT THE TFC WAS LEVELING AT 10000 FT AND IF WE DID ANYTHING WE SHOULD DSND. THE CAPT THEN SAID TO ME THAT MAYBE I SHOULD STOP THE CLB. I TOLD HIM THAT MANEUVERING IN OPPOSITION TO TCASII MIGHT CAUSE A MIDAIR REGARDLESS OF ATC INSTRUCTIONS. AT ABOUT 10300 FT, THE CAPT LOOKED OUT HIS SIDE WINDOW AND EXCLAIMED 'WHOA!' I LOOKED AND SAW THE TFC, AN ACR WDB, PASS US AT VERY CLOSE RANGE. THE ACR JET THEN TOLD APCH THAT TCASII WAS TELLING THEM TO DSND. IF WE HAD STOPPED OUR CLB WHEN ATC INSTRUCTED, WE MAY HAVE COLLIDED. I ALSO FEEL THAT ACR DID NOT COMPLY WITH ITS OWN TCASII AT FIRST, BECAUSE WE PASSED MUCH TOO CLOSE (THEY WERE PROBABLY AT THEIR ASSIGNED ALT OF 10000 FT). IT IS MY UNDERSTANDING THAT SOME PLTS ROUTINELY DISREGARD TCASII RA'S. TO PREVENT THESE SITS FROM RECURRING, CTLRS AND PLTS SHOULD BE EDUCATED MORE ABOUT THE DYNAMICS OF TCASII ENCOUNTERS. CTLRS NEED TO STAY OUT OF THE ENCOUNTER ONCE AN RA (OR RA'S) IS ISSUED, AND PLTS MUST STRICTLY COMPLY WITH THE RA. THE REASON I WAS SURE ABOUT WHAT TO DO WAS THAT I HAD JUST READ ABOUT THIS TYPE OF SIT IN A NASA CALLBACK.

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.