Narrative:

While descending into syr, aircraft heading approximately 105 degrees, ZOB issued what I thought was a '15 degree right' heading for a vector in our descent to 1000 ft. I must have misunderstood the vector and turned right to 120 degrees. Passing through 11300 ft. At the same time ZOB called about our heading, a TA alert appeared on our TCASII. The target was at our 2 O'clock, 3.5 NM, 500 ft above and climbing. It passed our 3 O'clock at 3 NM, 900 ft. Above and climbing. I immediately turned left to 090 degrees, after the target passed, and asked my copilot what heading was assigned. He felt the vector was '15 degrees left' and had set that on his heading bug, after reading back the clearance. He missed my turn to right, because he was starting to set up his radios for the approach plates. I have to assume the mistake was mine in making the turn in the wrong direction. However, I would have sworn I heard 'turn right 15 degrees.' this problem appears to be a classic communication breakdown. The center never did inform us of the nature of the vector or issue any traffic, that might have helped me to catch my own mistake.

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Original NASA ASRS Text

Title: HDG TRACK DEV CREATES A POTENTIAL CONFLICT. TCASII TA ALERTS FLC TO POSSIBLE FLC DEV IN THE CLRNC INTERP.

Narrative: WHILE DSNDING INTO SYR, ACFT HDG APPROX 105 DEGS, ZOB ISSUED WHAT I THOUGHT WAS A '15 DEG R' HDG FOR A VECTOR IN OUR DSCNT TO 1000 FT. I MUST HAVE MISUNDERSTOOD THE VECTOR AND TURNED R TO 120 DEGS. PASSING THROUGH 11300 FT. AT THE SAME TIME ZOB CALLED ABOUT OUR HDG, A TA ALERT APPEARED ON OUR TCASII. THE TARGET WAS AT OUR 2 O'CLOCK, 3.5 NM, 500 FT ABOVE AND CLBING. IT PASSED OUR 3 O'CLOCK AT 3 NM, 900 FT. ABOVE AND CLBING. I IMMEDIATELY TURNED L TO 090 DEGS, AFTER THE TARGET PASSED, AND ASKED MY COPLT WHAT HDG WAS ASSIGNED. HE FELT THE VECTOR WAS '15 DEGS L' AND HAD SET THAT ON HIS HDG BUG, AFTER READING BACK THE CLRNC. HE MISSED MY TURN TO R, BECAUSE HE WAS STARTING TO SET UP HIS RADIOS FOR THE APCH PLATES. I HAVE TO ASSUME THE MISTAKE WAS MINE IN MAKING THE TURN IN THE WRONG DIRECTION. HOWEVER, I WOULD HAVE SWORN I HEARD 'TURN R 15 DEGS.' THIS PROBLEM APPEARS TO BE A CLASSIC COM BREAKDOWN. THE CTR NEVER DID INFORM US OF THE NATURE OF THE VECTOR OR ISSUE ANY TFC, THAT MIGHT HAVE HELPED ME TO CATCH MY OWN MISTAKE.

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.