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Aircraft target goes into coast status causing controller to forget aircraft, then descend another aircraft to same altitude less than standard separation.
| Attributes | |
| ACN | 199861 |
| Time | |
| Date | 199201 |
| Day | Fri |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : omn airport : dab |
| State Reference | FL |
| Altitude | msl bound lower : 7000 msl bound upper : 7500 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other |
| Flight Phase | descent other |
| Route In Use | enroute : direct enroute airway : dab |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Flight Phase | cruise other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : approach |
| Qualification | controller : radar |
| Experience | controller military : 4 controller radar : 6 |
| ASRS Report | 199861 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument |
| Experience | flight time last 90 days : 108 flight time total : 2030 flight time type : 340 |
| ASRS Report | 199856 |
| Events | |
| Anomaly | non adherence : required legal separation non adherence : published procedure other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | controller : issued new clearance |
| Consequence | Other |
| Miss Distance | horizontal : 6000 vertical : 600 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Aircraft a was inbound from the north to dab. I descended him to 70 due to ftc at 60. Aircraft B was en route northbound at 70. Aircraft B went into coast when he flew over dab - I turned aircraft a on a 070 heading (over omn) vectors for descent. Aircraft B reacquired 2 mi north of dab. Aircraft a reported traffic off his front. I concurred and told aircraft a to descend to 60. I then called traffic to aircraft B who also concurred. There was no need for additional turns as aircraft a was already established in a turn and heading away from aircraft B. I had forgotten about aircraft B when he dropped off the scope. The conflict alert didnþt have time to go off by the time aircraft B reacquired. Supplemental information from acn 199856: we were air carrier a rdu to dab. Our clearance was from omn to dab and we were descending to our assigned altitude of 7000 ft descending through 8000 ft TCASII indicated an aircraft ahead less than 1000 ft below us. I visually picked up the aircraft about 2-3 mils in front of us and asked the controller about it. She responded that the traffic was northbound at 7000 ft. We started a left turn and the captain leveled the aircraft at about 7500 ft. The other aircraft passed approximately 500 ft below us and 1/2 mi to the right. Apparently the controller had cleared us to the same altitude as the northbound aircraft without giving us a vector to the east to set up for our approach to runway 25 at dab.
Original NASA ASRS Text
Title: ACFT TARGET GOES INTO COAST STATUS CAUSING CTLR TO FORGET ACFT, THEN DSND ANOTHER ACFT TO SAME ALT LTSS.
Narrative: ACFT A WAS INBOUND FROM THE N TO DAB. I DSNDED HIM TO 70 DUE TO FTC AT 60. ACFT B WAS ENRTE NBOUND AT 70. ACFT B WENT INTO COAST WHEN HE FLEW OVER DAB - I TURNED ACFT A ON A 070 HDG (OVER OMN) VECTORS FOR DSCNT. ACFT B REACQUIRED 2 MI N OF DAB. ACFT A RPTED TFC OFF HIS FRONT. I CONCURRED AND TOLD ACFT A TO DSND TO 60. I THEN CALLED TFC TO ACFT B WHO ALSO CONCURRED. THERE WAS NO NEED FOR ADDITIONAL TURNS AS ACFT A WAS ALREADY ESTABLISHED IN A TURN AND HDG AWAY FROM ACFT B. I HAD FORGOTTEN ABOUT ACFT B WHEN HE DROPPED OFF THE SCOPE. THE CONFLICT ALERT DIDNþT HAVE TIME TO GO OFF BY THE TIME ACFT B REACQUIRED. SUPPLEMENTAL INFO FROM ACN 199856: WE WERE ACR A RDU TO DAB. OUR CLRNC WAS FROM OMN TO DAB AND WE WERE DSNDING TO OUR ASSIGNED ALT OF 7000 FT DSNDING THROUGH 8000 FT TCASII INDICATED AN ACFT AHEAD LESS THAN 1000 FT BELOW US. I VISUALLY PICKED UP THE ACFT ABOUT 2-3 MILS IN FRONT OF US AND ASKED THE CTLR ABOUT IT. SHE RESPONDED THAT THE TFC WAS NBOUND AT 7000 FT. WE STARTED A L TURN AND THE CAPT LEVELED THE ACFT AT ABOUT 7500 FT. THE OTHER ACFT PASSED APPROX 500 FT BELOW US AND 1/2 MI TO THE R. APPARENTLY THE CTLR HAD CLRED US TO THE SAME ALT AS THE NBOUND ACFT WITHOUT GIVING US A VECTOR TO THE E TO SET UP FOR OUR APCH TO RWY 25 AT DAB.
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.