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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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Operational error between an air carrier DC9 and an air carrier EA31. Both aircraft were initially at FL310 on opposite direction courses. Reporter descended the DC9 to FL290 and turned the EA31. Separation was lost before the DC9 reached the assigned altitude. Reporter claims congestion and data block overlap with the DC9 was due to unexpected handoffs from rerted traffic from another center.
| Attributes | |
| ACN | 365548 |
| Time | |
| Date | 199704 |
| Day | Tue |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : pxv |
| State Reference | IN |
| Altitude | msl bound lower : 31000 msl bound upper : 31000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zid artcc : zkc |
| Operator | common carrier : air carrier |
| Make Model Name | DC-9 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise other descent other |
| Route In Use | enroute other |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | A310 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | cruise other |
| Route In Use | enroute : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Experience | controller non radar : 1 controller radar : 16 |
| ASRS Report | 365548 |
| Person 2 | |
| Affiliation | government : faa |
| Function | other personnel other |
| Qualification | controller : radar |
| ASRS Report | 365549 |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : published procedure non adherence : required legal separation |
| Independent Detector | other controllera |
| Resolutory Action | controller : issued new clearance other |
| Consequence | Other |
| Miss Distance | horizontal : 12600 vertical : 500 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Air carrier X eastbound at FL310. Air carrier Y wbound at FL310. Traffic was light to moderate, and starting to decrease. Due to rerted traffic over pxv from ZKC controller, received unexpected handoffs. This caused congestion and data block overlap around pxv with air carrier X. When data block was uncovered, controller realized air carrier X and air carrier Y would pass about less than 5 mi. Due to darc mode, conflict alert never activated. Air carrier X was descended and air carrier Y turned north. Separation was lost prior to air carrier X reporting FL290. Supplemental information from acn 365549: center radar (cdc) was not operational. The controller did not have all of his tools (conflict alert, dodectagon -- 5 mi ring, etc) and allowed 2 aircraft to converge at FL310. Controllers are trained to control using a variety of tools, and when the tools are not available due to equipment problem/failures, we as an agency, should be responsible for errors of this sort.
Original NASA ASRS Text
Title: OPERROR BTWN AN ACR DC9 AND AN ACR EA31. BOTH ACFT WERE INITIALLY AT FL310 ON OPPOSITE DIRECTION COURSES. RPTR DSNDED THE DC9 TO FL290 AND TURNED THE EA31. SEPARATION WAS LOST BEFORE THE DC9 REACHED THE ASSIGNED ALT. RPTR CLAIMS CONGESTION AND DATA BLOCK OVERLAP WITH THE DC9 WAS DUE TO UNEXPECTED HDOFS FROM RERTED TFC FROM ANOTHER CTR.
Narrative: ACR X EBOUND AT FL310. ACR Y WBOUND AT FL310. TFC WAS LIGHT TO MODERATE, AND STARTING TO DECREASE. DUE TO RERTED TFC OVER PXV FROM ZKC CTLR, RECEIVED UNEXPECTED HDOFS. THIS CAUSED CONGESTION AND DATA BLOCK OVERLAP AROUND PXV WITH ACR X. WHEN DATA BLOCK WAS UNCOVERED, CTLR REALIZED ACR X AND ACR Y WOULD PASS ABOUT LESS THAN 5 MI. DUE TO DARC MODE, CONFLICT ALERT NEVER ACTIVATED. ACR X WAS DSNDED AND ACR Y TURNED N. SEPARATION WAS LOST PRIOR TO ACR X RPTING FL290. SUPPLEMENTAL INFO FROM ACN 365549: CTR RADAR (CDC) WAS NOT OPERATIONAL. THE CTLR DID NOT HAVE ALL OF HIS TOOLS (CONFLICT ALERT, DODECTAGON -- 5 MI RING, ETC) AND ALLOWED 2 ACFT TO CONVERGE AT FL310. CTLRS ARE TRAINED TO CTL USING A VARIETY OF TOOLS, AND WHEN THE TOOLS ARE NOT AVAILABLE DUE TO EQUIP PROB/FAILURES, WE AS AN AGENCY, SHOULD BE RESPONSIBLE FOR ERRORS OF THIS SORT.
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.