Narrative:

I was sequencing jet arrs to ewr. I built a gap to put air carrier X in sequence. I issued a crossing restr to air carrier Y to cross pxt at FL290. I descended air carrier X to FL280 from FL330. 1 min later, air carrier Y reported leaving FL370 for FL290. Both aircraft were converging on pxt. Air carrier X was not descending very much. I issued a 040 degree heading for descent and asked air carrier Y his heading. He replied 030 degrees. I then issued air carrier X a 020 degree heading to ensure separation. I missed the readback. (At this time the aircraft were 8 mi apart and on diverging headings.) air carrier Y had answered and taken air carrier X's heading. After 2 updates on my display, I noticed air carrier Y turning at air carrier X - - both at FL300 and descending. I immediately turned both aircraft away from each other. After reviewing the audio tape recording I was shocked to hear that it was air carrier Y who read back the 020 degree heading and not air carrier X. He did not use the 'air carrier Y' in his call sign. It was a clear transmission to air carrier X, and they did not even question if the clearance was for them. I believe the classic hear what you want to hear is why I missed the readback, but if air carrier Y answered the turn for air carrier X by saying air carrier Y, I might have had a better chance to hear the mistake and immediately correct it. I was only working 4 aircraft on that frequency.

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Original NASA ASRS Text

Title: PLTDEV WHEN ACR Y RESPONDS AND TURNS TO HDG ASSIGNED TO ACR X. ACR Y DID NOT SEE COMPANY IDENT WHEN HDG WAS REPEATED. ACR X DID NOT CHALLENGE THE CLRNC. RPTR WAS NOT AWARE THAT ACR X HAD NOT ACKNOWLEDGED THE CLRNC UNTIL ACR Y'S TARGET WAS OBSERVED TURNING. LTSS.

Narrative: I WAS SEQUENCING JET ARRS TO EWR. I BUILT A GAP TO PUT ACR X IN SEQUENCE. I ISSUED A XING RESTR TO ACR Y TO CROSS PXT AT FL290. I DSNDED ACR X TO FL280 FROM FL330. 1 MIN LATER, ACR Y RPTED LEAVING FL370 FOR FL290. BOTH ACFT WERE CONVERGING ON PXT. ACR X WAS NOT DSNDING VERY MUCH. I ISSUED A 040 DEG HDG FOR DSCNT AND ASKED ACR Y HIS HDG. HE REPLIED 030 DEGS. I THEN ISSUED ACR X A 020 DEG HDG TO ENSURE SEPARATION. I MISSED THE READBACK. (AT THIS TIME THE ACFT WERE 8 MI APART AND ON DIVERGING HDGS.) ACR Y HAD ANSWERED AND TAKEN ACR X'S HDG. AFTER 2 UPDATES ON MY DISPLAY, I NOTICED ACR Y TURNING AT ACR X - - BOTH AT FL300 AND DSNDING. I IMMEDIATELY TURNED BOTH ACFT AWAY FROM EACH OTHER. AFTER REVIEWING THE AUDIO TAPE RECORDING I WAS SHOCKED TO HEAR THAT IT WAS ACR Y WHO READ BACK THE 020 DEG HDG AND NOT ACR X. HE DID NOT USE THE 'ACR Y' IN HIS CALL SIGN. IT WAS A CLR XMISSION TO ACR X, AND THEY DID NOT EVEN QUESTION IF THE CLRNC WAS FOR THEM. I BELIEVE THE CLASSIC HEAR WHAT YOU WANT TO HEAR IS WHY I MISSED THE READBACK, BUT IF ACR Y ANSWERED THE TURN FOR ACR X BY SAYING ACR Y, I MIGHT HAVE HAD A BETTER CHANCE TO HEAR THE MISTAKE AND IMMEDIATELY CORRECT IT. I WAS ONLY WORKING 4 ACFT ON THAT FREQ.

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.