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Flight crew of air carrier widebody transport did not descend as directed by TCASII RA since they had visual contact with the other aircraft during high altitude cruise.
| Attributes | |
| ACN | 271606 |
| Time | |
| Date | 199405 |
| Day | Thu |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : ydr |
| State Reference | SK |
| Altitude | msl bound lower : 37000 msl bound upper : 39000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | cruise other |
| Route In Use | enroute airway : czwg |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Flight Phase | descent other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 150 flight time total : 12000 flight time type : 500 |
| ASRS Report | 271606 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : required legal separation |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | none taken : anomaly accepted |
| Consequence | Other |
| Miss Distance | horizontal : 12000 vertical : 500 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Aircraft was at FL370 just east of ydr on a direct to dlh. I was relief first officer flying in the right seat. The other first officer in the captain's seat noticed another aircraft to our right that appeared to be at our altitude. A check of the TCASII confirmed that we were both at FL370. We immediately contacted winnipeg center and asked about other aircraft. ATC responded with a climb clearance to FL390, which we rapidly initiated. Passing FL37.5 we received an RA advising us to descend. Since we were above the other aircraft and had him in sight, we elected to continue climb rather than descend back down through his altitude. The other aircraft -- (air carrier Y flight) apparently began a descent because his altitude readout on our screen indicated a descent. Although we should have missed the other aircraft (air carrier Y), I believe that had we followed the TCASII RA advisory, we would have passed at least through his wake turbulence.
Original NASA ASRS Text
Title: FLC OF ACR WDB DID NOT DSND AS DIRECTED BY TCASII RA SINCE THEY HAD VISUAL CONTACT WITH THE OTHER ACFT DURING HIGH ALT CRUISE.
Narrative: ACFT WAS AT FL370 JUST E OF YDR ON A DIRECT TO DLH. I WAS RELIEF FO FLYING IN THE R SEAT. THE OTHER FO IN THE CAPT'S SEAT NOTICED ANOTHER ACFT TO OUR R THAT APPEARED TO BE AT OUR ALT. A CHK OF THE TCASII CONFIRMED THAT WE WERE BOTH AT FL370. WE IMMEDIATELY CONTACTED WINNIPEG CTR AND ASKED ABOUT OTHER ACFT. ATC RESPONDED WITH A CLB CLRNC TO FL390, WHICH WE RAPIDLY INITIATED. PASSING FL37.5 WE RECEIVED AN RA ADVISING US TO DSND. SINCE WE WERE ABOVE THE OTHER ACFT AND HAD HIM IN SIGHT, WE ELECTED TO CONTINUE CLB RATHER THAN DSND BACK DOWN THROUGH HIS ALT. THE OTHER ACFT -- (ACR Y FLT) APPARENTLY BEGAN A DSCNT BECAUSE HIS ALT READOUT ON OUR SCREEN INDICATED A DSCNT. ALTHOUGH WE SHOULD HAVE MISSED THE OTHER ACFT (ACR Y), I BELIEVE THAT HAD WE FOLLOWED THE TCASII RA ADVISORY, WE WOULD HAVE PASSED AT LEAST THROUGH HIS WAKE TURB.
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.