Narrative:

The 2 aircraft involved were assigned the same altitude west/O having the required sep for crossing tracks (15 mins). The problem was discovered when the aircraft, transiting from non radar to radar environment, were observed by the controller. At this time the aircraft had passed each other, therefore no action was taken nor was evasive action required. Factors contributing to this error were, lack of automated flight data processing on one of the aircraft, controller fatigue and sector overload. Callback conversation with reporter revealed the following: one of the aircraft, a widebody transport, was northbound on A22 at FL350. The other aircraft was wbound on a random route at FL350. Reporter stated that he simply missed the significance of both aircraft in conflict at the same altitude. In his report he stated that a contributing factor was controller workload. His estimate of traffic figures in the sector was 40 aircraft. Fatigue was also mentioned as a factor. Reporter was working his sixth day which is common, with 10 hours a day not uncommon. The primary cause of this conflict was his failure to see the pending conflict in time to descend one of the aircraft.

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Original NASA ASRS Text

Title: ACR-HVT CROSSED THE ROUTE OF AN ACR-WDB AT THE SAME ALT WITH LESS THAN STANDARD SEPARATION.

Narrative: THE 2 ACFT INVOLVED WERE ASSIGNED THE SAME ALT W/O HAVING THE REQUIRED SEP FOR XING TRACKS (15 MINS). THE PROB WAS DISCOVERED WHEN THE ACFT, TRANSITING FROM NON RADAR TO RADAR ENVIRONMENT, WERE OBSERVED BY THE CTLR. AT THIS TIME THE ACFT HAD PASSED EACH OTHER, THEREFORE NO ACTION WAS TAKEN NOR WAS EVASIVE ACTION REQUIRED. FACTORS CONTRIBUTING TO THIS ERROR WERE, LACK OF AUTOMATED FLT DATA PROCESSING ON ONE OF THE ACFT, CTLR FATIGUE AND SECTOR OVERLOAD. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: ONE OF THE ACFT, A WDB, WAS NBOUND ON A22 AT FL350. THE OTHER ACFT WAS WBOUND ON A RANDOM ROUTE AT FL350. RPTR STATED THAT HE SIMPLY MISSED THE SIGNIFICANCE OF BOTH ACFT IN CONFLICT AT THE SAME ALT. IN HIS RPT HE STATED THAT A CONTRIBUTING FACTOR WAS CTLR WORKLOAD. HIS ESTIMATE OF TFC FIGURES IN THE SECTOR WAS 40 ACFT. FATIGUE WAS ALSO MENTIONED AS A FACTOR. RPTR WAS WORKING HIS SIXTH DAY WHICH IS COMMON, WITH 10 HRS A DAY NOT UNCOMMON. THE PRIMARY CAUSE OF THIS CONFLICT WAS HIS FAILURE TO SEE THE PENDING CONFLICT IN TIME TO DSND ONE OF THE ACFT.

Data retrieved from NASA's ASRS site as of August 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.