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ZAU controller experienced operational error at FL300 when separation instructions to opposite direction traffic were too late to be effective.
| Attributes | |
| ACN | 723783 |
| Time | |
| Date | 200701 |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | navaid : dbq.vortac |
| State Reference | IA |
| Altitude | msl single value : 30000 |
| Environment | |
| Flight Conditions | VMC IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zau.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Regional Jet 700 ER&LR |
| Operating Under FAR Part | Part 121 |
| Flight Phase | descent : intermediate altitude |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zau.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | B757-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Experience | controller radar : 15 |
| ASRS Report | 723783 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | conflict : airborne critical non adherence : required legal separation |
| Independent Detector | atc equipment : conflict alert aircraft equipment : tcas other controllera |
| Resolutory Action | controller : issued new clearance controller : issued alert flight crew : took evasive action |
| Consequence | faa : investigated |
| Supplementary | |
| Problem Areas | ATC Human Performance |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Air carrier Y was a wbound overflt and air carrier X was an ord lander descending from FL330 to FL240. Conflict alert went off about 15 mi apart and opposite direction. I turned air carrier X 30 degrees left and expedited the aircraft down. He replied and stated that he had the traffic in sight. I then turned air carrier Y 30 degrees left. Air carrier Y did not respond to the clearance. Air carrier Y stated that he had a TCAS advisory and was responding to an alert. He was descending immediately. I was then going to turn the air carrier X further since I could no longer give control instructions to the air carrier Y due to the RA. But the air carrier X then informed me that he was also responding to an RA and descending. Due to the TCAS advisories and the RA instructions; the aircraft were closer together than they would have been if I had been able to separate them. If the air carrier Y had taken the 30 degree turn and not descended; then separation would not have been lost. The sector was also metering for ord with a controller on the d-side who was not certified for metering.
Original NASA ASRS Text
Title: ZAU CTLR EXPERIENCED OPERROR AT FL300 WHEN SEPARATION INSTRUCTIONS TO OPPOSITE DIRECTION TFC WERE TOO LATE TO BE EFFECTIVE.
Narrative: ACR Y WAS A WBOUND OVERFLT AND ACR X WAS AN ORD LANDER DSNDING FROM FL330 TO FL240. CONFLICT ALERT WENT OFF ABOUT 15 MI APART AND OPPOSITE DIRECTION. I TURNED ACR X 30 DEGS L AND EXPEDITED THE ACFT DOWN. HE REPLIED AND STATED THAT HE HAD THE TFC IN SIGHT. I THEN TURNED ACR Y 30 DEGS L. ACR Y DID NOT RESPOND TO THE CLRNC. ACR Y STATED THAT HE HAD A TCAS ADVISORY AND WAS RESPONDING TO AN ALERT. HE WAS DSNDING IMMEDIATELY. I WAS THEN GOING TO TURN THE ACR X FURTHER SINCE I COULD NO LONGER GIVE CTL INSTRUCTIONS TO THE ACR Y DUE TO THE RA. BUT THE ACR X THEN INFORMED ME THAT HE WAS ALSO RESPONDING TO AN RA AND DSNDING. DUE TO THE TCAS ADVISORIES AND THE RA INSTRUCTIONS; THE ACFT WERE CLOSER TOGETHER THAN THEY WOULD HAVE BEEN IF I HAD BEEN ABLE TO SEPARATE THEM. IF THE ACR Y HAD TAKEN THE 30 DEG TURN AND NOT DSNDED; THEN SEPARATION WOULD NOT HAVE BEEN LOST. THE SECTOR WAS ALSO METERING FOR ORD WITH A CTLR ON THE D-SIDE WHO WAS NOT CERTIFIED FOR METERING.
Data retrieved from NASA's ASRS site as of January 2009 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.