Narrative:

While descending from FL240 to FL220 I observed an aircraft climbing and overtaking us from the rear on TCASII. While leveling at FL220 we received an aural 'traffic' and the display turned yellow. I glanced out the left window and saw the B727 just in front of the left wing leading edge. I saw 1000 ft on the TCASII and commented he was 1000 ft below. Seconds later we received the climb command and as I looked left again, the B727 appeared to be making a slight left turn to avoid us and continued to climb, level at our altitude and cross our bow on approximately a 10-15 degree divergence. Copilot observed 300 ft on the TCASII. Communications were congested, we think we heard air carrier Y say he had visual contact. Moments later, air carrier Y ask if he should stay at FL220, he was then cleared to FL210. How the problem arose: ATC busy as usual, assigned a wrong altitude discovered by TCASII. New york approach was slow taking handoffs, 360 degrees in progress, frequency congestion, lots of aircraft in a small area. My error was not visually monitoring the B727. I assumed he would level off. If TCASII was working properly, he must have observed us in adequate time to maneuver his aircraft further away from mine. I would have. I will now monitor all aircraft till well clear. Actually, I don't know why he continued climbing and leveled at our altitude. I think I would have stopped at FL215.

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Original NASA ASRS Text

Title: A PVT LTT JET LEVEL AT FL220 IS ALERTED TO B727 TFC IN A CLB BELOW THEM BY TCASII. THE B727 ACFT THEN CONTINUED CLB RESULTING IN LOSS OF SEPARATION.

Narrative: WHILE DSNDING FROM FL240 TO FL220 I OBSERVED AN ACFT CLBING AND OVERTAKING US FROM THE REAR ON TCASII. WHILE LEVELING AT FL220 WE RECEIVED AN AURAL 'TFC' AND THE DISPLAY TURNED YELLOW. I GLANCED OUT THE L WINDOW AND SAW THE B727 JUST IN FRONT OF THE L WING LEADING EDGE. I SAW 1000 FT ON THE TCASII AND COMMENTED HE WAS 1000 FT BELOW. SECONDS LATER WE RECEIVED THE CLB COMMAND AND AS I LOOKED L AGAIN, THE B727 APPEARED TO BE MAKING A SLIGHT L TURN TO AVOID US AND CONTINUED TO CLB, LEVEL AT OUR ALT AND CROSS OUR BOW ON APPROX A 10-15 DEG DIVERGENCE. COPLT OBSERVED 300 FT ON THE TCASII. COMS WERE CONGESTED, WE THINK WE HEARD ACR Y SAY HE HAD VISUAL CONTACT. MOMENTS LATER, ACR Y ASK IF HE SHOULD STAY AT FL220, HE WAS THEN CLRED TO FL210. HOW THE PROB AROSE: ATC BUSY AS USUAL, ASSIGNED A WRONG ALT DISCOVERED BY TCASII. NEW YORK APCH WAS SLOW TAKING HDOFS, 360 DEGS IN PROGRESS, FREQ CONGESTION, LOTS OF ACFT IN A SMALL AREA. MY ERROR WAS NOT VISUALLY MONITORING THE B727. I ASSUMED HE WOULD LEVEL OFF. IF TCASII WAS WORKING PROPERLY, HE MUST HAVE OBSERVED US IN ADEQUATE TIME TO MANEUVER HIS ACFT FURTHER AWAY FROM MINE. I WOULD HAVE. I WILL NOW MONITOR ALL ACFT TILL WELL CLR. ACTUALLY, I DON'T KNOW WHY HE CONTINUED CLBING AND LEVELED AT OUR ALT. I THINK I WOULD HAVE STOPPED AT FL215.

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.