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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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Air carrier X unauthorized airspace entry had less than standard separation from air carrier Y. System error.
| Attributes | |
| ACN | 182474 |
| Time | |
| Date | 199106 |
| Day | Sun |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : bna |
| State Reference | TN |
| Altitude | msl bound lower : 9000 msl bound upper : 9000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : bna tower : hou |
| Operator | common carrier : air carrier |
| Make Model Name | Large Transport, Low Wing, 3 Turbojet Eng |
| Flight Phase | descent other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Flight Phase | climbout : intermediate altitude |
| Route In Use | enroute : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : approach |
| Qualification | controller : radar |
| Experience | controller radar : 8 |
| ASRS Report | 182474 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : departure |
| Qualification | controller : radar |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : published procedure non adherence : required legal separation other anomaly other |
| Resolutory Action | flight crew : took evasive action |
| Consequence | Other |
| Miss Distance | horizontal : 3000 vertical : 700 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error Intra Facility Coordination Failure |
Narrative:
I was working the east and west arrs at bna. Light traffic. Hazy visibility. I issued instructions to an arriving air carrier X to reduce speed to 250 KTS and then descend and maintain 6000 ft. This was in preparation for his turn to downwind and setting up for the visual approach to runway 20L. I had anticipated these instructions to have air carrier X leaving 10000 about 10 DME southeast of the VOR. At the same time departure control had an air carrier Y depart bna in a left turn (090) climbing to 9000. Air carrier X either got slowed down considerably, quicker than seems feasible or he started a descent prior to reaching 250 KTS. (Ground speed readout was 330 KTS leaving 9800 ft). Air carrier Y saw air carrier X and passed below him by 700 ft. My lesson learned is never to issue instructions that can be misused or misinterpreted again. Callback conversation with reporter revealed the following information: reporter stated was distracted by position relief briefing to decombine approach control positions. Reporter had descended air carrier X into departure control airspace without coordination. Reporter was not watching to see what air carrier X was doing. Conflict alert activated. Air carrier Y saw air carrier X and stopped climb. System error was filed.
Original NASA ASRS Text
Title: ACR X UNAUTHORIZED AIRSPACE ENTRY HAD LTSS FROM ACR Y. SYS ERROR.
Narrative: I WAS WORKING THE E AND W ARRS AT BNA. LIGHT TFC. HAZY VISIBILITY. I ISSUED INSTRUCTIONS TO AN ARRIVING ACR X TO REDUCE SPD TO 250 KTS AND THEN DSND AND MAINTAIN 6000 FT. THIS WAS IN PREPARATION FOR HIS TURN TO DOWNWIND AND SETTING UP FOR THE VISUAL APCH TO RWY 20L. I HAD ANTICIPATED THESE INSTRUCTIONS TO HAVE ACR X LEAVING 10000 ABOUT 10 DME SE OF THE VOR. AT THE SAME TIME DEP CTL HAD AN ACR Y DEPART BNA IN A L TURN (090) CLBING TO 9000. ACR X EITHER GOT SLOWED DOWN CONSIDERABLY, QUICKER THAN SEEMS FEASIBLE OR HE STARTED A DSCNT PRIOR TO REACHING 250 KTS. (GND SPD READOUT WAS 330 KTS LEAVING 9800 FT). ACR Y SAW ACR X AND PASSED BELOW HIM BY 700 FT. MY LESSON LEARNED IS NEVER TO ISSUE INSTRUCTIONS THAT CAN BE MISUSED OR MISINTERPRETED AGAIN. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFORMATION: RPTR STATED WAS DISTRACTED BY POS RELIEF BRIEFING TO DECOMBINE APCH CTL POSITIONS. RPTR HAD DSNDED ACR X INTO DEP CTL AIRSPACE WITHOUT COORD. RPTR WAS NOT WATCHING TO SEE WHAT ACR X WAS DOING. CONFLICT ALERT ACTIVATED. ACR Y SAW ACR X AND STOPPED CLB. SYS ERROR WAS FILED.
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.