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Air carrier X descent through occupied altitude TCASII RA had less than standard separation from air carrier Y TCASII RA. Evasive action taken. System error.
| Attributes | |
| ACN | 230622 |
| Time | |
| Date | 199301 |
| Day | Thu |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : ccv |
| State Reference | VA |
| Altitude | msl bound lower : 31000 msl bound upper : 31000 |
| Environment | |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zdc |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other Other |
| Flight Phase | descent other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Large Transport, Low Wing, 3 Turbojet Eng |
| Flight Phase | cruise other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Experience | controller radar : 1 |
| ASRS Report | 230622 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : published procedure non adherence : required legal separation |
| Independent Detector | atc equipment other atc equipment : unspecified aircraft equipment other aircraft equipment : unspecified |
| Resolutory Action | controller : issued new clearance flight crew : took evasive action other |
| Consequence | faa : investigated |
| Miss Distance | horizontal : 12000 vertical : 1600 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Intra Facility Coordination Failure Operational Error |
Narrative:
Traffic went from light to heavy and complex in matter of mins. Transferring controller causing confusion with constant calls on handoff line and not providing constant separation between air carrier X and 3 other acrs. Air carrier X northbound being overtaken by widebody transport. Air carrier Y sbound FL310. Transferring controller attempts point out on medium large transport climbing from FL300 to FL350 and then changes mind. Air carrier X given clearance to FL290 for bad ride and to resolve situation with widebody transport. Transferring controller again points out medium large transport climbing who is in conflict alert with handoff large transport. At FL330 medium large transport is also traffic for air carrier Y who is then turned left to avoid potential conflict with medium large transport. Conflict alert activates between air carrier X and air carrier Y. Both aircraft are issued turns to provide separation. Both aircraft advised me of TCASII alert and that they are executing resolution. Air carrier Y was not initially observed as traffic for air carrier X due to distraction caused by widebody transport overtaking, by multiple calls on handoff line, and by transferring controller attempting to climb medium large transport on boundary between sectors through parallel and head-on traffic.
Original NASA ASRS Text
Title: ACR X DSCNT THROUGH OCCUPIED ALT TCASII RA HAD LTSS FROM ACR Y TCASII RA. EVASIVE ACTION TAKEN. SYS ERROR.
Narrative: TFC WENT FROM LIGHT TO HVY AND COMPLEX IN MATTER OF MINS. TRANSFERRING CTLR CAUSING CONFUSION WITH CONSTANT CALLS ON HDOF LINE AND NOT PROVIDING CONSTANT SEPARATION BTWN ACR X AND 3 OTHER ACRS. ACR X NBOUND BEING OVERTAKEN BY WDB. ACR Y SBOUND FL310. TRANSFERRING CTLR ATTEMPTS POINT OUT ON MLG CLBING FROM FL300 TO FL350 AND THEN CHANGES MIND. ACR X GIVEN CLRNC TO FL290 FOR BAD RIDE AND TO RESOLVE SIT WITH WDB. TRANSFERRING CTLR AGAIN POINTS OUT MLG CLBING WHO IS IN CONFLICT ALERT WITH HDOF LGT. AT FL330 MLG IS ALSO TFC FOR ACR Y WHO IS THEN TURNED L TO AVOID POTENTIAL CONFLICT WITH MLG. CONFLICT ALERT ACTIVATES BTWN ACR X AND ACR Y. BOTH ACFT ARE ISSUED TURNS TO PROVIDE SEPARATION. BOTH ACFT ADVISED ME OF TCASII ALERT AND THAT THEY ARE EXECUTING RESOLUTION. ACR Y WAS NOT INITIALLY OBSERVED AS TFC FOR ACR X DUE TO DISTR CAUSED BY WDB OVERTAKING, BY MULTIPLE CALLS ON HDOF LINE, AND BY TRANSFERRING CTLR ATTEMPTING TO CLB MLG ON BOUNDARY BTWN SECTORS THROUGH PARALLEL AND HEAD-ON TFC.
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.