Narrative:

I was working the cape and ack sectors radar combined at sector 17 at the boston ARTCC. Two of the several aircraft I had on frequency, an air carrier X, large transport, bos mvy mvy 260 J174 XXX dca and air carrier Y, widebody transport, jfk ack tusky vysta XXX eddf. Both aircraft were climbing air carrier X to FL310 and air carrier Y to FL370. At XXXX the conflict alert activated on my radar scope. At XXXY I placed a 'J' ring on air carrier Y. Upon seeing a potential conflict developing I turned both aircraft to ensure separation. I turned air carrier X who was on an assigned heading of 235 degree to intercept mvy 260 radial to a new heading of 255 degree and turned air carrier Y 20 degree to the right. After observing the vector length it appeared that air carrier X had not made or was not turned enough, so I turned air carrier X to a new heading of 280 degree. After both aircraft passed I sent them on their respective routes. According to the operational error detection device I had 4.781 mi lateral separation and even with a 45 degree turn to air carrier X and a 20 degree turn to air carrier Y the separation reduced to 4.0 mi before both aircraft were clear of each other. This particular sector confign has led to many operational errors because of the narrow tunnel through which bos departures and overseas climbing traffic pass in close proximity to each other, approximately 7 mi. If the bos departure misses the turn just a fraction of a second, a head-on situation arises immediately.

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Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM ACR Y. SYSTEM ERROR.

Narrative: I WAS WORKING THE CAPE AND ACK SECTORS RADAR COMBINED AT SECTOR 17 AT THE BOSTON ARTCC. TWO OF THE SEVERAL ACFT I HAD ON FREQ, AN ACR X, LGT, BOS MVY MVY 260 J174 XXX DCA AND ACR Y, WDB, JFK ACK TUSKY VYSTA XXX EDDF. BOTH ACFT WERE CLIMBING ACR X TO FL310 AND ACR Y TO FL370. AT XXXX THE CONFLICT ALERT ACTIVATED ON MY RADAR SCOPE. AT XXXY I PLACED A 'J' RING ON ACR Y. UPON SEEING A POTENTIAL CONFLICT DEVELOPING I TURNED BOTH ACFT TO ENSURE SEPARATION. I TURNED ACR X WHO WAS ON AN ASSIGNED HDG OF 235 DEG TO INTERCEPT MVY 260 RADIAL TO A NEW HDG OF 255 DEG AND TURNED ACR Y 20 DEG TO THE RIGHT. AFTER OBSERVING THE VECTOR LENGTH IT APPEARED THAT ACR X HAD NOT MADE OR WAS NOT TURNED ENOUGH, SO I TURNED ACR X TO A NEW HDG OF 280 DEG. AFTER BOTH ACFT PASSED I SENT THEM ON THEIR RESPECTIVE ROUTES. ACCORDING TO THE OPERATIONAL ERROR DETECTION DEVICE I HAD 4.781 MI LATERAL SEPARATION AND EVEN WITH A 45 DEG TURN TO ACR X AND A 20 DEG TURN TO ACR Y THE SEPARATION REDUCED TO 4.0 MI BEFORE BOTH ACFT WERE CLEAR OF EACH OTHER. THIS PARTICULAR SECTOR CONFIGN HAS LED TO MANY OPERATIONAL ERRORS BECAUSE OF THE NARROW TUNNEL THROUGH WHICH BOS DEPS AND OVERSEAS CLIMBING TFC PASS IN CLOSE PROX TO EACH OTHER, APPROX 7 MI. IF THE BOS DEP MISSES THE TURN JUST A FRACTION OF A SECOND, A HEAD-ON SITUATION ARISES IMMEDIATELY.

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.